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Friday, June 10, 2011

Deaths no higher in coffee lovers with heart disease

Reuters Health

Friday, June 10, 2011

NEW YORK (Reuters Health) – Women with heart disease who down a few cups of coffee each day tend to live as long as those who avoid the beverage, a large study finds.

The results, reported in the American Journal of Clinical Nutrition, add to a mixed bag of research on whether caffeinated coffee is a hazard for people at high risk of heart problems.

In theory, coffee could be problematic because it has caffeine and other compounds that can raise blood pressure or have other negative effects on the cardiovascular system.

But some studies have found that coffee drinkers have no increased risk of a second heart attack or premature death. A few others have even hinted at protective effects from coffee.

In the new study, which followed nearly 12,000 U.S. nurses with a history of heart disease or stroke, those who regularly drank caffeinated coffee were no more likely to die than non-coffee-drinkers during the study period - which for some was more than 20 years.

Researchers found no link between a woman's coffee intake and her risk of death from heart attack, stroke or any other cause. And that was true even of women who downed four or more cups per day.

"Our results suggest that coffee drinking is OK for patients with cardiovascular disease, but it would be desirable to replicate our results in other populations," lead researcher Dr. Esther Lopez-Garcia, of Universidad Autonoma de Madrid in Spain, told Reuters Health in an email.

One problem with generalizing the current results, she explained, is that all the women in the study were nurses -- so they might not be representative of women with heart disease in general.

Nor can the study discount coffee as a possible cause of cardiovascular problems, at least in some people.

"What this study shows is that, in a general population, there's no obvious harm, or benefit, to consuming coffee after a heart attack," said Ahmed El-Sohemy, an associate professor at the University of Toronto who has studied coffee intake and heart health.

The problem is that certain individuals may benefit from some caffeine, while others may be harmed, according to El-Sohemy, who was not involved in the new study.

Recent studies have pointed to the importance of genetics, El-Sohemy told Reuters Health in an email.

Some research, for example, has linked coffee drinking to increased risks of high blood pressure in people who are naturally "slow metabolizes" of caffeine. But the reverse pattern has been seen in people who quickly process caffeine: more coffee, lower heart risks.

"What this study doesn't tell us is who might coffee be harmful to, and who might benefit from it," El-Sohemy said.

The findings come from the long-running Nurses' Health Study, which began tracking more than 100,000 female nurses in 1976. The researchers focused on 11,697 women who developed heart disease or had a stroke sometime between 1976 and 2002.

Of those women, 62 percent continued to drink caffeinated coffee after their diagnosis.

Overall, 1,159 women had died by 2004. That risk was no greater among coffee drinkers than non-drinkers, including women who drank at least four cups of java per day.

One possibility is that women in relatively worse health would choose to avoid caffeinated coffee, the study authors note. But they found no evidence that changes in women's coffee intake after their heart complication or stroke explained the findings.

They also accounted for factors like age, weight, high blood pressure and diabetes, and still found no association between coffee consumption and risk of death.

The findings, Lopez-Garcia said, "support the idea" that people with heart disease who already drink coffee do not have to give it up.

But she also advised checking with your doctor, particularly if you have uncontrolled high blood pressure or other conditions that could be aggravated by caffeine -- like sleep problems or anxiety.

El-Sohemy was even more cautious. It is hard to make individual recommendations on safe coffee intake, according to the researcher, because of genetic variations in people's caffeine metabolism.

"I don't see how any results can be interpreted from studies that don't take this genetic difference into account," El-Sohemy said.

Tests for genetic variations in the enzyme that processes caffeine are not routinely available, he noted.

Source: http://bit.ly/kUXi5R

American Journal of Clinical Nutrition, online May 11, 2011.

Chemical Found in Foam Cups a Possible Carcinogen

By Jenifer Goodwin
HealthDay Reporter

HealthDay News

Friday, June 10, 2011

FRIDAY, June 10 (HealthDay News) -- The chemical styrene, ubiquitous in foam coffee cups and take-out containers, has been added to the list of chemicals considered possible human carcinogens, according to a new U.S. government report.

On Friday, experts at the U.S. Department of Health and Human Services added styrene, along with five other chemicals -- captafol, cobalt-tungsten carbide (in powder or hard metal form), certain inhalable glass wool fibers, o-nitrotoluene and riddelliine -- to its list of 240 substances that are "reasonably anticipated" to be carcinogenic.

But before you toss those white plastic take-out containers, keep this in mind: the government report says that by far the greatest exposure to styrene comes from cigarette smoke. In fact, one study cited in the report estimates that exposure from smoking cigarettes was roughly 10 times that from all other sources, including indoor and outdoor air, drinking water, soil and food combined.

Styrene is a widely used chemical. Products that contain it include insulation, fiberglass, plastic pipes, automobile parts, drinking cups and other food containers and carpet backing, according to the Agency for Toxic Substances & Disease Registry.

Studies in the lab, animals and humans -- particularly workers in industries such as reinforced plastic that expose them to higher than normal levels of the chemical -- suggest that exposure to styrene causes damage in white blood cells, or lymphocytes and may raise the risk of lymphohematopoietic cancer, such as leukemia and lymphoma.

There is also evidence exposure may raise the risk of esophageal and pancreatic cancer among styrene-exposed workers, according to the Report on Carcinogens, prepared by the National Toxicology Program, part of the U.S. National Institutes of Health.

The report also issued its strongest warning about two other chemicals, formaldehyde (widely used as a preservative) and a botanical known as aristolochic acids, adding both to the list of "known" carcinogens.

"The strength of this report lies in the rigorous scientific review process," said Ruth Lunn, director of the National Toxicology Program Office of the Report on Carcinogens, in a news release.

Aristolochic acids have been shown to cause high rates of bladder or upper urinary tract cancer in people with kidney or renal disease who consumed botanical products containing aristolochic acids, according to the report. Despite a U.S. Food and Drug Administration warning against the use of products containing aristolochic acids, it can still be purchased on the Internet and abroad, particularly in herbal products used to treat arthritis, gout and inflammation.

Formaldehyde has long been listed as a substance "reasonable anticipated" to cause cancer after animal studies showed it increased the risk of nasal cancer. Since then, additional studies in humans have shown exposure increases the risk for certain types of rare cancers, including nasopharyngeal (the nasopharnyx is the upper part of the throat behind the nose), sinonasal and myeloid leukemia, a cancer of the white blood cells, prompting federal officials to strengthen its warning.

Formaldehyde is a colorless, flammable, strong-smelling chemical that is widely used to make resins for household items, such as composite wood products, paper product coatings, plastics, synthetic fibers, and textile finishes. Formaldehyde is also used as a preservative in medical laboratories, mortuaries, and in some hair straightening products.

Representatives of industry took issue with the addition of both formadelhyde and styrene to the NTP's list.

"It will unfairly scare workers, plant neighbors and could have a chilling effect on the development of new products," Tom Dobbins, a spokesman for the American Composites Manufacturers Association, told The New York Times. "Our companies are primarily small businesses, and this could hurt jobs and local economies."

The federal panelists were quick to stress that the public shouldn't panic over the inclusion of any one substance in the Report on Carcinogens.

"A listing in the report does not by itself mean that a substance will cause cancer," John Bucher, associate director of the NTP, told Bloomberg News in a conference call with reporters. Many factors, including the amount and duration of exposure, as well as an individual's susceptibility can affect whether a person will develop cancer.

More information

The U.S. Centers for Disease Control and Prevention's Agency for Toxic Substances & Disease Registry has more on styrene.

Crawling culprit seen in urban kids' asthma

By Alison McCook

Reuters Health

Friday, June 10, 2011

NEW YORK (Reuters Health) – Researchers have identified cockroaches as a potential explanation for dramatic variations between neighborhoods in asthma rates among New York City children.

In some New York City neighborhoods, 19 percent -- nearly 1 in 5 -- children have asthma; in others, the rate is as low as 3 percent.

Heavy traffic, industrial incinerators, and other outdoor air pollution sources have been blamed in the past as potential contributors to asthma differences across the city.

Now, researchers at Columbia University have found that children living in neighborhoods with high rates of asthma were twice as likely to carry antibodies against a cockroach protein in their blood, a sign the kids had been exposed to the insects and were likely allergic to them.

In addition, homes in the neighborhoods with high rates of asthma contained more of the allergen produced by cockroaches in household dust.

This study provides "further evidence that cockroach exposure is part of the story," study author Dr. Matthew Perzanowski told Reuters Health. "Cockroach allergen really could be contributing to disparities in asthma prevalence, even in an urban environment like New York City."

These findings also suggest that controlling cockroaches may help eliminate some of those disparities, Perzanowski noted. But parents don't want to spray tons of harmful chemicals, which could "have other detrimental effects," he added.

Instead, people can take simple steps such as sealing up any cracks, and removing food and water sources. (The New York City Department of Health and Mental Hygiene offers advice for combatting roaches at http://www.nyc.gov/html/doh/html/ehs/ehscroach.shtml )To investigate why some city neighborhoods have more asthma cases than others, Perzanowski and his team visited the homes of 239 seven- and eight-year-olds, half of whom lived in areas with high asthma rates.

Previous research has linked poverty to an increased risk of asthma in childhood. To eliminate the influence of income on the results, the authors only included families with the same middle-income health insurance plan, to ensure they had the same income and access to health care.

More than half of the children already had asthma.

During home visits, the researchers collected dust from the children's beds, then took blood samples to look for antibodies against various allergens associated with asthma -- including cat, dog, mouse, dust mite and cockroach proteins.

Nearly 1 in 4 kids living in neighborhoods with high asthma rates appeared to be allergic to cockroaches, compared to 1 in 10 kids living in areas where asthma is less common.

Homes in high-asthma communities also had higher concentrations of the cockroach allergen, as well as allergens associated with mice and cats, the authors report in the Journal of Allergy and Clinical Immunology.

In addition, kids who were allergic to cockroaches and mice were more likely to have asthma, noted Dr. Joanne Sordillo at the Channing Laboratory, affiliated both with Brigham and Women's Hospital and Harvard Medical School, who reviewed the findings for Reuters Health.

"Mouse or cockroach allergen exposure may increase the risk of allergic sensitization (allergies), which is in turn related to the development of asthma in children," she said in an email.

Although cockroach protein sensitization was more common in kids in high-asthma neighborhoods, overall, children who were allergic to dust and cats were also more likely to have asthma.

Perzanowski explained that cockroaches leave behind proteins that people inhale and can become allergic to, which in turn increases the chance they will develop asthma.

But when it comes to cat ownership, the picture gets a bit murkier, he explained. Some previous research has found that kids in homes with cats were more likely to be allergic, but in this study, having a cat did not predispose kids to asthma.

"It's complicated," the researcher said. "Avoidance of cats doesn't seem to reduce your risk of developing asthma."

Source: http://bit.ly/km9BZP

Journal of Allergy and Clinical Immunology, online May 4, 2011.

Study May Dispel Worries About High Levels of Folic Acid

HealthDay News

Friday, June 10, 2011

FRIDAY, June 10 (HealthDay News) -- Consuming high amounts of folate -- through supplements and foods fortified with folic acid -- does not disrupt a healthy body's use of vitamin B12, according to new research.

Folic acid -- the synthetic form of the vitamin folate -- is added to grain products in the United States to reduce women's risk of conceiving a child with a neural tube birth defect. But some worry that folic acid levels in these foods may be too high for other people. Their concerns stem from studies that found that people with low B12 levels and high folate levels were more likely to have anemia than those with low B12 levels and normal folate levels.

B12 is needed to make red blood cells, and people with low levels of B12 can develop anemia, as well as numbness and tingling in the hands and feet.

The new study found, however, that anemia and other problems related to low levels of vitamin B12 were not likely to get worse with higher intake of folic acid.

It included more than 2,500 university students who reported the amount and type of folic acid-fortified foods and folic acid supplements they consumed in the previous week and in an average month. Blood samples collected from the participants showed that about 5 percent were B12 deficient. Of the students with low B12 levels, there was no significant difference in rates of anemia between those with high and those with low folate levels.

The study, conducted by researchers at the U.S. National Institute of Child Health and Human Development and five other institutions in the United States, Ireland and Norway, was published online June 8 in the American Journal of Clinical Nutrition.

"Our findings are reassuring for people who have low vitamin B12 levels," Dr. James L. Mills, the study's first author, said in a U.S. National Institutes of Health news release. "We found no evidence that folate could worsen their health problems."

Natural sources of folate include leafy green vegetables, citrus fruits and beans.

More information

The U.S. Centers for Disease Control and Prevention has more about folic acid.

Thursday, June 9, 2011

Study Confirms Safety, Cancer-Targeting Ability of Nutrient in Broccoli, Other Vegetables, Researchers Say

ScienceDaily

Thursday, June 9, 2011

ScienceDaily (June 9, 2011) — Sulforaphane, one of the primary phytochemicals in broccoli and other cruciferous vegetables that helps them prevent cancer, has been shown for the first time to selectively target and kill cancer cells while leaving normal prostate cells healthy and unaffected.

The findings, made by scientists in the Linus Pauling Institute at Oregon State University, are another important step forward for the potential use of sulforaphone in cancer prevention and treatment. Clinical prevention trials are already under way for its use in these areas, particularly prostate and breast cancer.

It appears that sulforaphane, which is found at fairly high levels in broccoli, cauliflower and other cruciferous vegetables, is an inhibitor of histone deacetylase, or HDAC enzymes. HDAC inhibition is one of the more promising fields of cancer treatment and is being targeted from both a pharmaceutical and dietary approach, scientists say.

"It's important to demonstrate that sulforaphane is safe if we propose to use it in cancer prevention or therapies," said Emily Ho, a principal investigator in the Linus Pauling Institute, lead author on the study and associate professor in the OSU Department of Nutrition and Exercise Sciences.

"Just because a phytochemical or nutrient is found in food doesn't always mean its safe, and a lot can also depend on the form or levels consumed," Ho said. "But this does appear to be a phytochemical that can selectively kill cancer cells, and that's always what you look for in cancer therapies."

The findings were published in Molecular Nutrition and Food Research, a professional journal. Research was supported by the National Cancer Institute, National Institute of Environmental Health Sciences and the OSU Agricultural Experiment Station.

The Linus Pauling Institute has conducted some of the leading studies on sulforaphane's role as an HDAC inhibitor -- one, but not all, of the mechanisms by which it may help prevent cancer. HDACs are a family of enzymes that, among other things, affect access to DNA and play a role in whether certain genes are expressed or not, such as tumor suppressor genes.

Some of the mechanisms that help prevent inappropriate cell growth -- the hallmark of cancer -- are circumvented in cancer cells. HDAC inhibitors can help "turn on" these silenced genes and restore normal cellular function.

Previous OSU studies done with mouse models showed that prostate tumor growth was slowed by a diet containing sulforaphane.

"It is well documented that sulforaphane can target cancer cells through multiple chemopreventive mechanisms," the researchers wrote in their study. "Here we show for the first time that sulforaphane selectively targets benign hyperplasia cells and cancerous prostate cells while leaving the normal prostate cells unaffected."

"These findings regarding the relative safety of sulforaphane to normal tissues have significant clinical relevance as the use of sulforaphane moves towards use in human clinical trials," they said.

The results also suggest that consumption of sulforaphane-rich foods should be non-toxic, safe, simple and affordable.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Journal Reference:

John D. Clarke, Anna Hsu, Zhen Yu, Roderick H. Dashwood, Emily Ho. Differential effects of sulforaphane on histone deacetylases, cell cycle arrest and apoptosis in normal prostate cells versus hyperplastic and cancerous prostate cells. Molecular Nutrition & Food Research, 2011; DOI: 10.1002/mnfr.201000547

Drugs for Enlarged Prostate May Raise Risk of Aggressive Cancer

By Steven Reinberg
HealthDay Reporter

HealthDay News

Thursday, June 9, 2011

THURSDAY, June 9 (HealthDay News) -- The U.S. Food and Drug Administration is calling for new warning labels on a class of drugs used primarily to treat enlarged prostates, because the medications may raise the risk of developing an aggressive form of prostate cancer.

In a statement released Thursday, the agency said the drugs involved include popular medications sold under the brand names Proscar and Propecia (sold by Merck & Co.) and Avodart and Jalyn (sold by GlaxoSmithKline).

According to the FDA, almost 5 million men were prescribed one of these medications between 2002 and 2009. Of these, nearly 3 million men were between the ages of 50 and 79.

The agency is advising doctors not to start patients on these drugs until prostate cancer -- which can mimic the symptoms of an enlarged prostate -- and other urological conditions have been ruled out.

According to the agency, this new warning is based on the results of two large prostate cancer trials.

Although these trials did not include Propecia, which is prescribed to treat hair loss in men, its label is also being updated. However, the FDA said "the applicability of the Avodart and Proscar studies to Propecia, is currently unknown."

All of these drugs are part of a class of medications called 5-alpha reductase inhibitors (5-ARI). According to the FDA, Proscar, Avodart and Jalyn are approved to treat symptoms of enlarged prostate, while Proscar and Avodart are also approved to reduce the risk of urinary retention or surgery related to an enlarged prostate. Propecia is a lower-dose version of Proscar.

Merck issued a statement Thursday on the FDA ruling.

"Merck stands behind the demonstrated safety and efficacy of Proscar [finasteride, 5mg] and Propecia [finasteride, 1mg]. Both products have been prescribed to millions of men, with Proscar prescribed to those suffering from benign prostatic hyperplasia (BPH or enlarged prostate) since 1992, and Propecia prescribed to men with male pattern hair loss since 1997," the company statement said. "Merck's goal is to ensure the product labeling includes all relevant trial information to help health-care professionals and their patients make informed treatment decisions."

Less than a year ago, GlaxoSmithKline asked the FDA to approve the use of Avodart to prevent prostate cancer, although the FDA declined that request in January. The company based its reasoning on the results of one of the trials on which the agency is now basing its new warning.

In addition to this new side effect, recent research has shown that Proscar, Propecia and Avodart are all associated with increasing the risk of erectile dysfunction in men who take the medications.

Commenting on the FDA warning, prostate cancer expert Dr. Anthony D'Amico, chief of genitourinary radiation oncology at Brigham and Women's Hospital in Boston, said, "I think that the warning is appropriate. The risk is very small, but not zero."

"What both studies show conclusively is there is about a 1 percent increase in being diagnosed with high-grade prostate cancer if you got these drugs -- even though you are less likely to get a low-grade cancer."

Why that is is not clear, D'Amico said. "But I think the warning is fair," he added.

The drugs really do work in preventing prostate cancer, D'Amico said. "You have to weigh the 24 percent reduction against the 1 percent increased incidence of high-grade disease," he said.

"These drugs should only be used in men who have an additional indication to take them beyond prostate cancer prevention," D'Amico said.

More information

For more on prostate cancer, visit the American Cancer Society.

Will eating more broccoli help you live longer?

By Eric Schultz

Reuters Health

Thursday, June 9, 2011

NEW YORK (Reuters Health) – To the likely delight of nagging parents, a new study shows that people who eat more fruit and veggies tend to live longer.

Plants from the mustard family -- including broccoli, cabbage, and cauliflower -- seem particularly beneficial, although the study can't prove that eating more vegetables automatically increases longevity.

It's possible, for instance, that those who consume lots of produce also have a healthier lifestyle in general.

Still, the findings "provide strong support for the current recommendation to increase vegetable consumption to promote cardiovascular health and overall longevity," study researcher Dr. Xianglan Zhang, of Vanderbilt University School of Medicine in Nashville, Tennessee, told Reuters Health.

Mustard-family vegetables are high in vitamin C and fiber and also contain other nutrients that may have health benefits.

The study, published in the American Journal of Clinical Nutrition, is based on a survey of nearly 135,000 adults from Shanghai, China.

Participants filled out questionnaires about their eating habits and health history, and the researchers then divided them into five categories according to how much produce they ate.

Over five years, four percent of the people died. Those who downed the most vegetables or fruits, however, were 15 percent less likely to die over that period than those who ate the fewest.

For mustard-family vegetables, there was an even bigger difference in death rates between people with high and low intakes.

The researchers found a similar pattern when they looked at people dying from heart disease -- about a quarter of all deaths in the study. But there was no evidence that eating fruits and vegetables was linked to cancer risk.

According to Dr. Lydia Bazzano, who was not involved in the study, the results are promising. But they don't prove that just eating more fruit and vegetables will necessarily make people live longer.

"Unmeasured health habits may account for some of the association,"

Bazzano, of Tulane University Health Sciences Center in New Orleans, told Reuters Health.

The researchers did try to rule out alternative explanations -- such as age, weight, exercise, vitamin use, and smoking -- but acknowledge there could be more factors at play.

Still, they encourage people to eat more produce, especially vegetables from the mustard family, as a step toward living longer, healthier lives.

Heart disease is the leading killer worldwide, causing more than 600,000 deaths every year in the U.S., according to the Centers for Disease Control and Prevention. The CDC recommends eating two to four cups of fruit and vegetables daily.

Source: http://bit.ly/isQvG1

American Journal of Clinical Nutrition, online May 18, 2011.

Wednesday, June 8, 2011

Group of blood pressure drugs not linked to cancer

By Eric Schultz

Reuters Health

Wednesday, June 8, 2011

NEW YORK (Reuters Health) – Despite concerns that blood pressure drugs may increase the risk of cancer, a new study suggests that a particular such drug may not be linked to that risk.

Angiotensin-converting enzyme inhibitors, usually referred to as ACE inhibitors, are not associated with a higher rate of cancer, according to a study by researchers at University Hospitals Case Medical Center in Cleveland.

"There were worries in the scientific community that ACE inhibitors were associated with cancer," study co-author Dr. Ilke Sipahi told Reuters Health. The study results, he added, "confirm the safety of ACE inhibitors as far as cancer goes."

ACE inhibitors lower blood pressure by blocking the production of a chemical that causes blood vessels to contract. In addition to controlling blood pressure, they are used to improve survival after heart attacks, and prevent strokes. Before this study, there was a mixed picture about whether ACE inhibitors were linked to cancer.

A previous study by Sipahi's group, for example, found that a similar group of drugs, known as angiotensin receptor blockers, was associated with an increased likelihood of cancer.

In the new study, published in The American Journal of Cardiology, the researchers reviewed existing trials of ACE inhibitors that measured how many patients developed or died of cancer. One of those previous studies linked ACE inhibitors to an increased risk of digestive system cancers, but the authors did not find any association in this review.

Sipahi did caution that the reviewed studies followed patients for a maximum of 5 years, so the team could not determine the effect of ACE inhibitors on the risk of developing cancer over a period longer than 5 years.

Still, the limitations of the data mean that more research is needed, Dr. Christopher Phillips, of Morehouse School of Medicine in Atlanta, Georgia, told Reuters Health.

Phillips, who was not involved in the study, noted that the authors only dove deeply into data for one type of ACE inhibitor, enalapril, marketed as Vasotec. The study showed that enalapril does not increase the risk of cancer, he said. But "can we attribute that to all the ACE inhibitors or just enalapril?"

The limitations mean that the study "should not affect the current clinical prescribing of ACE inhibitors to eligible patients who need them," Phillips said.

Patients taking ACE inhibitors may experience side effects, including cough, headache, drowsiness, or weakness, and in rare cases, kidney failure or swelling of tissues. They range from $10 per month for generic drugs to more than $100 per month for brand names.

Source: http://bit.ly/knld9o

The American Journal of Cardiology, online May 25, 2011.

Regular Exercise May Benefit the Brain as Well as the Body

HealthDay News

Wednesday, June 8, 2011

WEDNESDAY, June 8 (HealthDay News) -- A commitment to high-intensity exercise may keep more than just your body in good shape. New research reveals that long-term aerobic activity may also boost a person's brain function.

In the study, Benjamin Tseng, a researcher in the Institute for Exercise and Environmental Medicine's (IEEM) Cerebrovascular Lab at the Texas Health Presbyterian Hospital Dallas, and colleagues compared brain structure and function in 10 athletes and 10 sedentary people.

The types of brain function they looked at included muscle control, executive function (a type of cognition that includes working memory, self-monitoring and the ability to suppress distractions) as well as other neurological functions.

"We know that brain structure and some aspects of cognitive function deteriorate with aging, but we haven't been able to find exactly what the contributing factors and mechanisms are," Tseng said in a hospital news release. "Our preliminary results shed light on this important topic, and we hope the findings lead to better prevention and treatment of Alzheimer's disease and other forms of dementia."

The study participants included 10 Masters athletes, average age 73 years, who had at least 15 years of competitive aerobic training, and 10 sedentary people of a similar age and education level. The investigators found that the brain's white matter fiber was better preserved among the athletes than the inactive people.

In the human brain, white matter plays the critical role of transmitting messages between different regions of gray matter -- areas where functions such as seeing, hearing, speaking, memory and emotions take place. So, without sufficient white matter, gray matter can't do its job, as is the case for many people with various forms of dementia, the study authors explained in the news release.

"Without properly functioning white matter, people can begin to show signs of neurological problems," Dr. Benjamin Levine, director of the IEEM and a professor of medicine and cardiology and a distinguished professor in exercise science at UT Southwestern Medical Center, explained in the news release. "They can lose the ability to do simple daily tasks that we take for granted."

The researchers concluded that their study sheds some light on the mysteries of the aging brain, such as how brain blood flow is related to its structure and function.

"It also tells us that long-term aerobic exercise has definitive, measurable impact on brain health," said Levine. "Most importantly, it lets us know that we have tools that can help fight off dementia and some of the other classic signs of aging with a purposeful, consistent exercise regimen."

The findings were scheduled for presentation this week at the annual meeting of the American College of Sports Medicine, held in conjunction with the World Congress on Exercise Is Medicine, in Denver. Because this study was presented at a medical meeting, the data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.

More information

The U.S. National Library of Medicine provides more information on dementia.

Low-fat diet may not increase diabetes risks

By Genevra Pittman

Reuters Health

Wednesday, June 8, 2011

NEW YORK (Reuters Health) – While the low-fat diet craze led some doctors to worry that Americans would instead start eating too many carbohydrates, a new study suggests that eating low-fat doesn't have to increase carbohydrate-fueled health risks.

Instead, if extra carbohydrates are part of a diet plan that includes more fruits, vegetables, and whole grains, the risk of diabetes - the biggest related health concern -- could actually drop, at least in older women, according to the findings.

However, a low-fat, high-carbohydrate diet could create problems in people who already have diabetes, researchers caution.

"Generally when people reduce the fat in the diet they replace it with carbohydrates," study author Dr. James Shikany told Reuters Health. "There was some concern that the increased carbohydrate intake might lead to if not increased diabetes itself...changes that over time could lead to diabetes."

"We had been telling women to decrease their fat intake for a long time and we really didn't know the possible effects this would have" on diabetes, added Shikany, from the University of Alabama at Birmingham.

The results suggest that balancing both diabetes and other disease risks requires considering the kinds of carbohydrates, fats, and proteins we eat, researchers said, rather than just cutting back on one food group and eating more of another.

The study, published in the American Journal of Clinical Nutrition, included a group of about 2,300 postmenopausal women who were part of the Women's Health Initiative trial, which looked at the effect of diet and hormone therapy on disease risks.

About 900 of the women, selected randomly, were told to decrease their total fat intake so that fat accounted for about 20 percent of the calories in their diet. For a 2,000-calorie diet, that would mean eating 44 grams of fat each day.

As part of the new diet, women were also told to increase the number of fruit, vegetable, and grain servings they ate, and they attended regular sessions with nutritionists to help them do that.

The other 1,400 women, serving as a comparison group, were not given any extra nutritional guidance or told to change their diet.

The researchers followed women for the next 6 years with surveys on diet and exercise and also tested their blood for sugar and insulin levels to look for diabetes or its warning signs.

Women in the low-fat group, on average, said they got between 25 and 29 percent of their calories from fat in follow-up surveys. That compared to 36 to 37 percent in the group without a diet intervention.

U.S. government guidelines suggest adults get between 20 and 35 percent of their calories from fat.

The diet group also generally ate fewer total calories and more fruits, vegetables, grains, and sugar than the comparison group, on average.

After 1 year, women on the low-fat diet had lost more weight than the comparison group and had bigger decreases in their blood sugar and insulin levels. By 6 years, the groups looked similar on those measures. That told researchers that the lower-fat, higher-carbohydrate diet hadn't increased women's chances of getting diabetes.

However, in women who already had diabetes at the start of the study, those on the low-fat diet had a larger increase in blood sugar levels in the first year compared to women who didn't change their diet. That could be because people with diabetes had lost the ability to process the extra carbohydrates, Shikany said.

Carbohydrates are "obviously not a poison," said Dr. David Jenkins, head of the Clinical Nutrition and Risk Factor Modification Center at St. Michael's Hospital in Toronto. "If eaten wisely (they're) useful."

However, in general, "we went from a diet that was rich in saturated fat and cholesterol and was also not good (to) a diet which was equally tasty, but relying on refining the carbohydrates in a particular way" that ups the risk of obesity and diabetes, Jenkins, who was not involved in the new research, told Reuters Health.

Refined carbohydrates include white bread and rice and sugary drinks and snacks.

Jenkins said that getting more fat and protein from vegetable sources, such as by eating beans or adding hummus or peanut butter to bread, is a good way to stave off both diabetes and heart disease.

Doctors now generally recommend a diet that has plenty of healthy, non-saturated fats, rather than one that tries to cut back on all fats, Shikany said - but that doesn't mean the new data isn't useful.

"Things have kind of changed, but there still are plenty of (doctors) who recommend low-fat diets and people who are on these diets," he said. "I certainly think it's a very safe diet, but the question is, is this the best diet?"

Mary Gannon, of the University of Minnesota, said that a diet lower in carbohydrates and higher in fat and protein may actually help people feel fuller sooner - which could lead to weight loss over time. In male patients with diabetes she has studied, men had the most improvement in diabetes markers when they got the smallest percent of their calories from carbohydrates.

Shikany added that because the research was limited to women age 50 and up, his findings don't necessarily apply to men or younger women on a low-fat diet.

Source: http://bit.ly/ktCLuv

American Journal of Clinical Nutrition, online May 11, 2011.

New Guidelines Put Focus on Vitamin D Deficiency

HealthDay News

Wednesday, June 8, 2011

WEDNESDAY, June 8 (HealthDay News) -- It has long been known that getting enough vitamin D is key to bone health, yet vitamin D deficiency remains a common health issue, experts say.

According to the Endocrine Society, very few foods naturally contain or are fortified with vitamin D, and sunlight is one of the best sources of the nutrient.

People who don't get enough vitamin D are at risk for calcium, phosphorus and bone metabolism abnormalities, which can lead to a number of diseases, including osteoporosis. Children with a vitamin D deficiency can also develop skeletal deformities known as rickets, the experts pointed out in a society news release.

"Vitamin D deficiency is very common in all age groups, and it is important that physicians and health-care providers have the best evidence-based recommendations for evaluating, treating and preventing vitamin D deficiency in patients at highest risk," Dr. Michael F. Holick, of Boston University School of Medicine, said in the news release. Holick chairs a task force that authored the society's new clinical practice guidelines published in the July issue of the Journal of Clinical Endocrinology & Metabolism.

The Endocrine Society issued the guidelines in response to the possible health risks associated with vitamin D deficiency. Among the group's recommendations:

People who are considered at high risk should be routinely screened for vitamin D deficiency.

People who are diagnosed with a vitamin D deficiency should be treated with either a vitamin D2 or vitamin D3 supplement.

To maximize bone health and muscle function, people considered at high risk for a deficiency should adhere to the following guidelines for dietary intake of vitamin D:

Infants up to 12 months of age require at least 400 international units (IU) a day.

Children older than 1 year and adults from 19 to 70 years old, including pregnant and lactating women, should consume at least 600 IU daily.

People older than 70 years should get a minimum of 800 IU a day.

The task force stressed that in order to raise the blood level of vitamin D consistently above 30 nanograms per milliliter, a significantly higher intake of vitamin D may be required. The group also noted that vitamin D screening is not necessary for people who are not considered at risk for the deficiency. And, it said there is no evidence supporting use of vitamin D supplements for benefits other than bone health.

More information

The U.S. Office of Dietary Supplements has more on vitamin D.

"Silent" strokes less common in physically fit

By Alison McCook

Reuters Health

Wednesday, June 8, 2011

NEW YORK (Reuters Health) – People who participate in vigorous activity are less likely to experience so-called "silent" strokes, new study findings report.

Specifically, older adults who got the most exercise - equivalent to swimming or biking more than once per week - were 40 percent less likely to experience a silent stroke, in which brain scans show a stroke occurred, but they experienced no symptoms.

Even though these strokes are "silent," people who experience them are more at risk of other problems in the future, such as trouble with walking or mental functioning, as well as typical strokes, explained study author Dr. Joshua Willey at Columbia University.

He and his colleagues found that people who engaged in less vigorous exercise - perhaps doing vigorous activity less frequently, or sticking with low-impact exercise such as golfing or bowling - were no less likely to experience silent strokes.

The study doesn't prove whether physical activity actually prevents stroke. People who participate in such activity may have other habits, or characteristics, that lower their risks.

Still, exercise is helpful for other reasons, Willey said.

"We know that light to moderate exercise helps with many other conditions. And we don't want our results to discourage our patients from doing exercise. Any is better than none, just in general, for overall health," Willey told Reuters Health. "And it seems to be, the more the better."

The study included older adults, many of whom can continue to play tennis, swim, bike, and do other types of vigorous exercise, he said. But before starting a program, it's important to consult your regular doctor or cardiologist, to ensure it's safe, Willey cautioned. Vigorous activity "can be safe once cleared."

During the study, Willey and his team at Columbia and the University of Miami interviewed more than 1,200 people 55 and older who had no symptoms of stroke and were already participating in a study on the risk of stroke about physical activity, then performed brain scans to check for "silent" strokes.

Among the participants, who averaged 70 years of age at the time of their brain scan, 16 percent had experienced a silent stroke, known as silent brain infarcts. Only those who engaged in the most activity had a reduced risk, the authors note in the journal Neurology.

It was somewhat surprising to see that people who engaged in less vigorous forms of exercise were not protected from silent strokes, said Willey.

"That throws us off a little bit."

Previous studies have also shown, however, that only moderate or heavy exercise appears to ward off stroke, he noted. In addition, only 36 percent of participants engaged in light exercise, and this may not be enough people to reveal a true impact, Willey added.

Physical activity had no relationship to the risk of another silent brain event, white matter hyperintensities (WMHs), in which brain scans reveal damage to the channels the brain uses to send instructions to the rest of the body.

WMHs are also linked to later problems, such as dementia and trouble walking, as well as typical stroke, said Willey. Experts remain unclear about what causes WMHs, he noted, and something about the reasons for WMHs may explain the lack of relationship to exercise.

"We need to understand more what these white matter hyperintensities are we're witnessing."

Willey cautioned that this study only shows people who exercised heavily had a lower risk, not that exercise itself prevented silent strokes. In addition, he and his colleagues only measured physical activity by asking people what they did over the previous 2 weeks, and brain scans occurred several years after the exercise interview, which could have affected the findings.

He and his colleagues plan to look at relationships between brain scans and exercise in people who report their activity every year, he added. "We will look into that in the future."

Source: http://bit.ly/Q5TNl

Neurology, 2011.

Brain Scans to Spot Alzheimer's May Be Available This Year

By Randy Dotinga
HealthDay Reporter

HealthDay News

Wednesday, June 8, 2011

WEDNESDAY, June 8 (HealthDay News) -- Brain scans that detect early warning signs of Alzheimer's may be available in the United States as soon as this year, researchers reported this week, though it may be too early for the scans to be of much help for those with the disease.

"You'll get a more accurate and earlier diagnosis, which can be important to people who want to know what's going on when their memory is starting to decline," said Dr. Christopher Rowe, lead author of one study on the scans. "Unfortunately, until there's an effective therapy, there's nothing that can be done to stop the progression of the disease. The real value is going to come when we have an effective therapy."

According to the Alzheimer's Association, the disease is the sixth leading cause of death in the United States, and the number of deaths has risen in recent years.

Rowe and other researchers just released studies that reveal the effectiveness of PET scans that search for signs of a protein in the brain called beta-amyloid. It essentially gunks up the brain and causes senility.

In one of three new studies, researchers from University of Texas found that levels of the protein, as detected through a PET scanner, were higher in those whose brains took longer to process things. In older people, they linked higher levels to memory problems.

Physicians who find signs of senility in people who undergo brain scans have limited options to help them. There's no cure for the illness, and drug treatments have not proven to be very effective.

Rowe, who's director of nuclear medicine at the Center for PET at Austin Hospital in Melbourne, Australia, said that one company, Avid Radiopharmaceuticals, hopes to get federal approval for amyloid scanning technology by the end of the year. Rowe has consulted for the company.

The scans won't be cheap, according to Rowe, potentially costing thousands of dollars each in the United States. But they accurately diagnose Alzheimer's about 90 percent of the time, he said, compared with an 80 percent rate that physicians reach on their own. And, he said, the scans can detect Alzheimer's at an early stage.

Dr. James R. Burke, director of the Memory Disorders Clinic at Duke University Medical Center, wondered about the value of diagnosis via scanner.

"Would you scan all people over a certain age?" he asked. "What do you say to a cognitively normal individual with increased amyloid in his/her brain that you would not advise for the same person without amyloid? If we had a therapy that reduced amyloid and prevented cognitive decline, then an argument could be made for widespread use of these scans."

However, Burke said, the study of brain scans does have value now as a research tool.

The studies were scheduled to be presented at the annual meeting of the Society of Nuclear Medicine, June 4 to 8 in San Antonio, Texas. Experts note that research presented at meetings should be considered preliminary because it has not been subjected to the rigorous scrutiny given to research published in medical journals.

More information

The U.S. National Institute on Aging has more on Alzheimer's disease.

Shingles May Be Related to Elevated Risk of Multiple Sclerosis

ScienceDaily

Wednesday, June 8, 2011

ScienceDaily (June 8, 2011) — Taiwanese investigators have found that there can be a significantly higher risk of multiple sclerosis (MS) occurring in the year following a shingles, or herpes zoster, attack. The findings, which support a long-held view on how MS may develop, are published in The Journal of Infectious Diseases and now available online.

MS is an autoimmune disease that affects the brain and spinal cord, leading to inflammation and nerve damage as the body's immune cells attack the nervous system. Possible causes that may trigger the inflammation include environmental, genetic, and viral factors. One virus that has been associated with MS is varicella zoster virus, the cause of herpes zoster.

In a study conducted by Herng-Ching Lin, PhD, and colleagues at Taipei Medical University in Taiwan, 315,550 adults with herpes zoster and a control group of 946,650 subjects were tracked and then evaluated for MS occurrence during a one-year follow-up period. The control group was selected randomly from a pool of subjects who had not been diagnosed with herpes zoster or other viral diseases. After adjusting for monthly income and geographic region, the authors found that the group with herpes zoster had a 3.96 times higher risk of developing MS than the control group. The authors noted that this risk, although increased, was still low, as is the frequency of MS in general. The study also noted an interval of approximately 100 days between a herpes zoster event and occurrence of MS.

Although the study was limited almost entirely to Han Chinese adults, the large scope of this nationwide case-controlled study, 1.26 million sampled patients, provides strong epidemiological evidence for a possible role for herpes zoster in the development of MS. The authors also point out that MS has a lower prevalence in Asian compared to Western populations and, thus, it may be difficult to project their findings to other populations.

In an accompanying editorial, Teresa Corona, MD, and Jose Flores, MD, of the National Institute of Neurology and Neurosurgery in Mexico noted that "The evidence provided in this study…allows us to better understand the role of these viral factors as an MS risk among certain genetically susceptible individuals," and that the study should be corroborated in other parts of the world to help clarify the role of this and other viruses in MS.

Fast Facts:

There is epidemiological evidence that some herpes viruses may contribute to multiple sclerosis (MS) occurrence.

The rate of MS prevalence varies by geographical location and income.

In this study, investigators found a significantly higher -- but still low -- risk for MS occurring in the year following a shingles, or herpes zoster, attack compared to a control population.

There is evidence that 30 percent of relapses in MS patients may be associated with an infectious disease.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Journal References:

  1. Jiunn-Horng Kang, Jau-Jiuan Sheu, Senyeong Kao and Herng-Ching Lin. Increased Risk of Multiple Sclerosis Following Herpes Zoster: A Nationwide, Population-Based Study. J Infect Dis., June 7, 2011 DOI: 10.1093/infdis/jir239
  2. Teresa Corona and José Flores. Herpes Zoster and Multiple Sclerosis. Journal of Infectious Diseases, June 7, 2011 DOI: 10.1093/infdis/jir243

Impaired Heart Function Seen in Teens With Type 2 Diabetes

HealthDay News

Wednesday, June 8, 2011

WEDNESDAY, June 8 (HealthDay News) -- Some teens with type 2 diabetes already show signs of impaired heart function, researchers report.

"Past studies in adults with type 2 diabetes show that their heart and blood vessels' ability to adapt to exercise may be impaired. Our study shows that these changes in heart function may begin to happen very early after type 2 diabetes occurs," study author Dr. Teresa Pinto, a pediatric endocrinologist at the Dalhousie University IWK Health Center in Halifax, Nova Scotia, said in an Endocrine Society news release.

Pinto and colleagues examined how the heart and blood vessels of 13 teens with type 2 diabetes responded to exercise, compared to 27 non-diabetic overweight or obese teens and 19 non-diabetic normal-weight teens. The participants were aged 12 to 20, and the study was conducted while Pinto was at the University of Auckland in New Zealand.

MRI scans revealed that during exercise, the hearts of teens with type 2 diabetes did not expand and fill up with blood between heart beats as well as the hearts of the teens in the other two groups. The amount of blood pumped out by the heart was normal in all three groups.

"We showed that the heart's pumping function is strong, but it is not filling as well as normal between heart beats. This is known as diastolic dysfunction," Pinto said. "Although this study did not determine the reason for this, we know that with diabetes, the heart can become stiffer, limiting its ability to stretch and expand."

Pinto and her colleagues also found that teens with diabetes had significantly less blood flow through the femoral arteries (large arteries in the thigh) during exercise compared to the other two groups.

"It appears that irrespective of weight, type 2 diabetes seems to have a negative effect on the heart and blood vessels in adolescents," Pinto said. "This impaired exercise capacity may be reversible with exercise training however, as some literature in adults suggests, but further studies are required to determine this."

The study was slated for presentation this week at the Endocrine Society's annual meeting in Boston. Experts noted that research presented at meetings should be viewed as preliminary until published in a peer-reviewed journal.

More information

The Nemours Foundation has more about diabetes in children and teens.

Breast Cancer Drug Pushes Colon Cancer Cells to Their Death

ScienceDaily

Wednesday, June 8, 2011

ScienceDaily (June 8, 2011) — A new treatment for colon cancer that combines a chemotherapy agent approved to treat breast cancer and a cancer-fighting antibody is ready for clinical trials, according to Penn State College of Medicine researchers.

More than 150,000 cases of colorectal cancer are diagnosed each year, and about 50,000 people die from colorectal cancer yearly. Currently there are limited chemotherapy treatments for colorectal cancer with little that has been in the pipeline in recent years.

Wafik S. El-Deiry, M.D. Ph.D., American Cancer Society Research Professor and Rose Dunlap Professor and chief of hematology/oncology, and his team have tested lapatinib, a targeted chemotherapy agent currently approved for breast cancer treatment, in a new combination with artificial antibodies that mimic a natural cancer-fighting protein produced in the human body. The monoclonal antibodies mapatumumab and lexatumumab act similarly to TRAIL -- tumor necrosis factor [TNF]-related apoptosis-inducing ligand -- a naturally occurring molecule in the body that tells a cell it is time to die. TRAIL sets a process in motion that targets and shuts down tumor cells and keeps them from spreading.

"These are therapeutic antibodies that are manufactured very efficiently, and given to patients," said El-Deiry, who is also the associate director for translational research, Cancer Institute.

The TRAIL receptors -- death receptors -- on the cancer cells respond to TRAIL by dying. The artificial antibodies act as surrogates of TRAIL by activating the same signaling pathway resulting in tumor cell death.

The monoclonal antibodies have an advantage over TRAIL because they remain active in the body for a longer period of time. TRAIL receptor antibodies last for less than 30 minutes, while the artificial monoclonal antibodies last for about nine days. Although the antibodies can act similarly to TRAIL, they do not completely substitute for TRAIL and ultimately which one gets used in what situation is still being tested in clinical trials. But for the purpose of these new advances either one works.

Lapatinib increases the amount of "death receptor" protein available for TRAIL to do its job -- killing off cancerous cells -- El-Deiry and his colleagues report in this week's issue of Science Translational Medicine.

The researchers tested the lapatinib and monoclonal antibody combination in mice. Separately, the two treatments did not increase tumor cell suppression -- but when the drugs were administered together, the researcher found that cell death escalated.

"We have discovered a mechanistic basis for combining these drugs that says one drug upregulates the receptor for the other drug, and maybe now when we combine these two drugs we'll get an even better synergy between them," said El-Deiry. "I think that's probably the most exciting result, to be able to provide a molecular rationale for a new treatment combination for difficult-to-treat advanced colorectal cancers."

The Food and Drug Administration approved lapatinib in 2007 for use as a breast cancer chemotherapy. It blocks two specific types of proteins located on tumor cell surfaces from causing tumors to grow. These proteins are a potent way that tumors are signaled to grow -- and if the proteins are blocked, there is one less mechanism for tumors to proliferate. However, in the treatment El-Deiry has proposed, lapatinib would be used off-label by increasing a different tumor cell death-inducing protein to help colon cancer patients.

Also working on this research were Nathan G. Dolloff, Ph.D; Patrick A. Mayes, Ph.D.; Lori S. Hart, Ph.D.; David T. Dicker, technical specialist; and Robin Humphreys, Human Genome Sciences. The National Institutes of Health supported this research.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Journal Reference:

Nathan G. Dolloff, Patrick A. Mayes, Lori S. Hart, David T. Dicker, Robin Humphreys, and Wafik S. El-Deiry. Off-Target Lapatinib Activity Sensitizes Colon Cancer Cells Through TRAIL Death Receptor Up-Regulation. Science Translational Medicine, 2011; 3 (86): 86ra50 DOI: 10.1126/scitranslmed.3001384

Dieters More Likely to Trust Food Packaging

HealthDay News

Wednesday, June 8, 2011

WEDNESDAY, June 8 (HealthDay News) -- Dieters are more likely than non-dieters to be misled by food names, a new study says.

For example, dieters rated food items with names such as "salad" as being healthier than identical products with names such as "pasta," while non-dieters made no such distinctions.

Dieters also believed that candy labeled "fruit chew" was healthier than the same candy when it was labeled "candy chew," and ate more of the candy when it was called fruit chews, said the University of South Carolina researchers.

"The fact that people's perceptions of healthfulness vary with the name of the food item isn't surprising. What is interesting is that dieters, who try to eat healthy and care about what they eat, fell into these 'naming traps' more than non-dieters who really don't care about healthy eating," study author Caglar Irmak, an assistant professor of marketing, said in a university news release.

The findings from the study of more than 520 people suggest that dieters rely on food names to identify supposedly healthy foods, Irmak explained. Instead, dieters need to focus on reading nutritional information on food products and restaurant menus.

"These results should give dieters pause. The study shows that dieters base their food decisions on the name of the food item instead of the ingredients of the item. As a result, they may eat more than what their dieting goals prescribe," Irmak said.

The study appears in the August issue of the Journal of Consumer Research.

More information

The American Heart Association offers no-fad diet tips.

An Alternative to Antibiotics

ScienceDaily

Wednesday, June 8, 2011

ScienceDaily (June 8, 2011) — Antibiotics are among the greatest achievements of medical science. But lately the former multi-purpose weapon fails in the battle against infectious diseases. Bacteria are increasingly developing resistance to antibiotics. Researchers have now found a therapeutic equivalent which could replace penicillin and related phamaceuticals.

More and more pathogens are becoming immune to antibiotics. Some bacteria can no longer be combated. The World Health Organization WHO is warning about resistance to drugs which were once so potent. The WHO's director-general Margaret Chan has pointed out that if measures are not taken quickly, it may soon not be possible to treat many frequently occurring infections. Figures released by the WHO show that in 2010 nearly half-a-million people were infected with a strain of tuberculosis which is resistant to many antibiotics -- one third of those infected died. The Organization states that the growing spread of resistant pathogens is attributable to the indiscriminate use of penicillin and other antibiotics. Research scientists at the Fraunhofer Institute for Cell Therapy and Immunology IZI in Leipzig have found an alternative to the established antibiotics. In the future, antimicrobial peptides will take up the battle against pathogens.

"We have already identified 20 of these short chains of amino acids which kill numerous microbes, including enterococci, yeasts and molds, as well as human pathogenic bacteria such as Streptococcus mutans, which is found in the human oral cavity and causes tooth decay. Even the multi-resistant hospital bug Staphylococcus aureus is not immune, and in our tests its growth was considerably inhibited," says Dr. Andreas Schubert, group manager at Fraunhofer IZI.

From familiar fungicidal and bactericidal peptides the research scientists produced sequence variations and tested them in vitro on various microbes. Putrefactive bacteria, for example, were incubated for an hour with the artificially produced antimicrobial peptides. As the new peptides contain cationic amino acid residues, they can bond with the negatively charged bacterial membrane and penetrate it. In their tests the research scientists compared the survivability of the pathogens with an untreated control. The experts focused on peptides with a length of less than 20 amino acids.

"Antibiotic peptides unlock their microbicidal effect within a few minutes. They also work at a concentration of less than 1 µM, compared with conventional antibiotics which require a concentration of 10 µM," states Schubert, summarizing the test results. "The spectrum of efficacy of the tested peptides includes not only bacteria and molds but also lipid-enveloped viruses. Another key factor is that the peptides identified in our tests do not harm healthy body cells," the scientist explains.

The food sector could also benefit from the antimicrobial peptides given that the bacterial contamination of food products costs the industry billions every year. Fresh lettuce and other salad greens, for example, are badly contaminated by yeasts and molds. The shelf-life of foodstuffs could be improved by adding antimicrobial peptides during the production process. "This is a definite possibility because the short-chain peptides tested during the project do not exhibit any allergological risk on being added to foodstuffs," says Schubert. Magdeburg-based company ÖHMI Analytic GmbH is the project partner in the development of peptides for salad greens. The research scientist is convinced that many possible applications exist, including in machinery manufacture -- for instance to keep hydraulic fluids free of microbes. As a next step the expert and his team are going to test the antimicrobial peptides in vivo on infection models.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff. 

Tuesday, June 7, 2011

Apple Ingredient Keeps Muscles Strong: Component of Apple Peels Found to Help Prevent Muscle Weakening in Mice

ScienceDaily

Tuesday, June 7, 2011

ScienceDaily (June 7, 2011) — In search of a way to prevent the muscle wasting that comes with illness and aging, researchers have landed a natural compound that might just do the trick. The findings reported in the June issue of Cell Metabolism, a Cell Press publication, identify a component of apple peels as a promising new drug candidate for the widespread and debilitating condition that affects nearly everyone at one time or another.

"Muscle wasting is a frequent companion of illness and aging," said Christopher Adams of The University of Iowa, Iowa City. "It prolongs hospitalization, delays recoveries and in some cases prevents people from going back home. It isn't well understood and there is no medicine for it."

Motivated by the desire to change that, Adams' team first looked at what happens to gene activity in muscles under conditions that promote weakening. Those studies turned up 63 genes that change in response to fasting in both people and mice and another 29 that shift their expression in the muscles of both people who are fasting and those with spinal cord injury. Comparison of those gene expression signatures to the signatures of cells treated with more than 1300 bioactive small molecules led them to ursolic acid as a compound with effects that might counteract those of atrophy.

"Ursolic acid is an interesting natural compound," Adams said. "It's part of a normal diet as a component of apple peels. They always say that an apple a day keeps the doctor away…"

The researchers next gave ursolic acid to fasted mice. Those experiments showed that ursolic acid could protect against muscle weakening as predicted. When ursolic acid was added to the food of normal mice for a period of weeks, their muscles grew. Those effects were traced back to enhanced insulin signaling in muscle and to corrections in the gene signatures linked to atrophy.

Animals given ursolic acid also became leaner and had lower blood levels of glucose, cholesterol and triglycerides. The findings therefore suggest that ursolic acid may be responsible for some of the overall benefits of healthy eating.

"We know if you eat a balanced diet like mom told us to eat you get this material," Adams said. "People who eat junk food don't get this."

It is not yet clear whether the findings in mice will translate to human patients, Adams says, but his goal now is to "figure out if this can help people." If so, they don't yet know whether ursolic acid at levels that might be consumed as part of a normal diet might or might not be enough.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Journal Reference:

Steven D. Kunkel, Manish Suneja, Scott M. Ebert, Kale S. Bongers, Daniel K. Fox, Sharon E. Malmberg, Fariborz Alipour, Richard K. Shields, Christopher M. Adams. mRNA Expression Signatures of Human Skeletal Muscle Atrophy Identify a Natural Compound that Increases Muscle Mass. Cell Metabolism, 2011; 13 (6): 627-638 DOI: 10.1016/j.cmet.2011.03.020

U.S. cancer drugs shortage has doctors scrambling

By Debra Sherman and Julie Steenhuysen

Reuters

Tuesday, June 7, 2011

CHICAGO (Reuters) – Cancer medicines desperately needed by sick children and adults are in short supply, undermining the ability of U.S. doctors to administer treatments, top oncologists warned this week.

Many drugs are scarce because there is no incentive for drugmakers to manufacture low-cost generics, which have slim profit margins for pharmaceutical companies. Doctors do not expect that equation to change any time soon, making them scramble to find acceptable alternatives, or to ration or delay treatment when they cannot.

Generic chemotherapy drugs are in particularly tight supply at the nation's hospitals, including mainstay cancer treatments such as cisplatin, doxorubicin, cytarabine and leucovorin.

"These are chestnuts. These are not old-fashioned drugs. They remain incredibly important drugs which serve as the backbone for treating many of the most common and treatable cancers," said Dr. Robert Mayer of the Dana-Farber Cancer Institute in Boston and a past president of American Society of Clinical Oncology (ASCO) which held its annual meeting in Chicago this week.

Cisplatin is used to treat testicular, bladder and ovarian cancers that have spread. The drug, also used to treat lung cancers, is sold under multiple brand names, originally by Bristol-Myers Squibb. A generic form is sold by Teva Pharmaceutical Industries Ltd, among others.

Doxorubicin, also available under multiple brands and as a generic from Teva and others, is used to treat non-Hodgkin's lymphoma, multiple myeloma, acute leukemias and other cancers.

Cytarabine, produced by Hospira Inc and others, is used to treat certain types of leukemia. Leucovorin, also sold by Teva, is used along with certain chemotherapy drugs to treat colorectal, head and neck and other cancers.

Dr. Michael Link, a pediatric oncologist at the Mayo Clinic and current ASCO president, called it a disheartening crisis.

"Here we have highly effective drugs, they've been shown they work and to think we don't have them available is almost unconscionable," Link said. "We don't see an end in sight."

In some cases, doctors can substitute another drug for one that is in short supply.

"It's still uncomfortable to say that this is ideally what we'd like to do, but unfortunately we don't have it," Link said. "You can imagine the conversation and I'm sure they're going on all over -- doctors have to tell their patients or their patients' parents that we can't give them the proven drug because we don't have it."

No Substitute

For some of these medicines in short supply, there may not be acceptable alternatives.

"One could say that substituting Pepsi for Coca-Cola doesn't make a difference. Maybe it does and maybe it doesn't," Mayer said. "But more often it might be substituting 7-UP for Coca-Cola, and that might make a difference."

Leucovorin, a form of folic acid that is used to enhance the effectiveness of other chemotherapy drugs, is one example.

"This is the one that I hear the most about from my colleagues. If you don't have it, you just have to omit it. It certainly isn't in the best interest of patients. It is a very inexpensive drug," Mayer said.

Sophia Parhas, a pharmacy manager at Children's Memorial Hospital in Chicago, said if there is a shortage of the generic, the hospital will often buy the branded product.

"We make some substitutions ... so doctors will go back and forth between daunorubicin and doxorubicin, depending upon which one is short," she said.

Another option is for doctors to flip the order that drugs are given depending on the supply situation. Allen Vaida, executive vice president of the Institute for Safe Medical Practices, which has been tracking the shortage, said doctors have also been forced to delay or ration treatments.

"Patients are started on a therapy and they may go through four or five or six cycles. When a drug becomes short, your cycle may be coming up a month later than planned," he said.

"Oncologists, especially in major cancer centers, are in a quandary. 'Do I start my patient on therapy? Do I save what I have for patients who started two cycles ago?'"

Dr. Richard Schilsky, cancer specialist at the University of Chicago and a past ASCO president, said the shortages have been going on for about nine months with no sign of abating.

"When you talk to the drug companies, they say there are manufacturing problems or they are taking plants offline and then it takes a while to get them back up," he said.

"They point the finger at the FDA (Food and Drug Administration), saying the FDA is under-resourced and they can't get plants inspected to allow resumption of drug production. The drug suppliers are in the middle of this as well," he said.

But underlying all of this, he said, is a dearth of financial incentive to make the lower-cost cancer drugs, especially when new cancer drugs command huge premium prices.

"The return on investment of manufacturing generic drugs is pretty low. If something goes wrong, it may be that some manufacturers decide to pull out rather than fix the problem."

Hospira spokesman Dan Rosenberg said shortages arise for many reasons -- capacity constraints, commodity shortfalls, or when a competitor withdraws its product for some reason or when competitors have shortfalls. It is not always possible for Hospira to ramp up production that quickly, Rosenberg said.

"We are doing everything we can to ensure access to these products for clinicians and patients," he said. "Often, we continue manufacturing products at a loss because we realize there is a critical medical need and we are the only company that provides the medication."

A Teva spokesman said its California plant that makes injectable drugs, which was closed last year due to quality issues, is now back up. But the plant will not reach full capacity until the end of this year.

To address the shortages, U.S. senators Amy Klobuchar, a Democrat from Minnesota, and Robert Casey, a Democrat from Pennsylvania, introduced a bill in February that would make drug companies inform the FDA about supply problems or plans to stop making a drug. The FDA would then have time to work with other suppliers to make the drugs or arrange for imports.

"That is a canary in the coal mine," Schilsky said. "It doesn't really resolve the fundamental problem."

(Reporting by Debra Sherman and Julie Steenhuysen; Editing by Michele Gershberg and Matthew Lewis)

Fetal Exposure to BPA Changes Development of Uterus in Primates, Study Suggests

ScienceDaily

Tuesday, June 7, 2011

ScienceDaily (June 7, 2011) — Exposure in the womb to bisphenol A (BPA), a chemical widely used in the food and medical industries, causes changes in female primates' uterus development, new research suggests.

The results are being presented at The Endocrine Society's 93rd Annual Meeting in Boston.

"Previous studies have shown that BPA can affect the reproductive tract. However, because the studies were done in rodents, it was uncertain if this would also be true in humans," said Carmen Williams, MD, PhD, a clinical investigator with the National Institute of Environmental Sciences (NIEHS), Research Triangle Park, N.C.

The new study used the rhesus monkey, a species that is very similar to humans in regard to pregnancy and fetal development, said Williams, a study co-author.

She and her colleagues conducted the research at NIEHS and the California National Primate Research Center in Davis, which co-funded the study with the NIEHS. During a period that represented the third trimester of human pregnancy, the investigators gave BPA to 12 pregnant monkeys, each carrying a single female fetus.

In the first year of the experiment, six monkeys received BPA orally in a fruit treat, at a dose of 400 micrograms per kilogram of body weight daily, the researchers reported. During the second year, six additional pregnant monkeys received BPA through capsules implanted subcutaneously (below the skin), for a daily dose of 100 micrograms per kilogram. Both forms of BPA resulted in a BPA level in the blood that is close to levels normally found in adult women, according to the authors' abstract.

The investigators analyzed the uterus of each offspring for gene expression. Oral BPA altered expression of HOX and WNT genes that are critical for uterine development, they found. They are still analyzing the data for the animals that received subcutaneous BPA, Williams said.

Differences also appeared in the extent of development of the cells lining the uterine cavity in BPA-exposed animals but not in a control group of unexposed monkeys.

"The long-term effects of BPA exposure on reproductive tract development are unknown," Williams said. "However, this research supports the recommendation that pregnant women should limit their exposure to BPA."

Experts recommend minimizing BPA exposure by using BPA-free products when possible and reducing consumption of canned foods, many of which are lined with BPA-containing epoxy resin.

The study findings were presented by Kathryn Calhoun, MD, an NIEHS research fellow based at the University of North Carolina, Chapel Hill.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Age Alone May Not Cause Testosterone to Fall

By Maureen Salamon
HealthDay Reporter

HealthDay News

Tuesday, June 7, 2011

TUESDAY, June 7 (HealthDay News) -- Testosterone levels don't necessarily drop with age, but it's more likely among older men with declining general health, a new study suggests.

Bucking prior research indicating age-related testosterone deficiency contributes to deteriorating health, fatigue and libido loss, Australian researchers found that blood testosterone amounts didn't fall in older men with optimal health.

The data, gathered as part of the Healthy Man Study, is scheduled to be presented Tuesday at the Endocrine Society's annual meeting in Boston.

"Our interpretation is that age in and of itself does not reduce blood testosterone levels . . . but the accumulating disorders as men age, some preventable and some not, some genetic and some environmental, do have such an impact, albeit pretty modest," said study author Dr. David Handelsman, a professor of reproductive endocrinology and andrology at the University of Sydney.

"This would make the drive for testosterone treatment for the well-known -- but overrated -- age-related decline in blood testosterone misguided," added Handelsman, also director of the university's ANZAC Research Institute. "But, of course, we could be wrong."

Handelsman and his team took blood samples nine times over three months from 325 men over age 40 who reported being in excellent health. Men who took medications that affect testosterone were excluded from the research.

While age had no effect on testosterone concentrations, obesity was linked to a minor decline, the scientists said.

Dr. Ronald Swerdloff, chief of the division of endocrinology at Harbor-UCLA Medical Center in Los Angeles, noted that other studies had documented a greater drop in testosterone among older men and called Handelsman's research "a piece of the puzzle."

"Many people agree that acute and chronic illness will adversely affect blood testosterone levels, so that's not a surprise," said Swerdloff. "But there are reductions that seem to be independent of co-morbid conditions. The fact of the matter is, with an increase in age [comes] a decrease in testosterone levels, [but] the degree of fall differs from study to study, and the variation could be due to many factors."

Swerdloff said he doesn't support companies who try to profit from older men's fears of declining testosterone by selling supplements that purportedly offset the drop.

"Theoretically, they're exploiting the population and taking advantage of a condition that may be real, but not universal, in order to gain financial reward," he said.

Because this study was presented at a medical meeting, the data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.

More information

For more on testosterone, go to the U.S. National Library of Medicine.

Bisphenol A (BPA) Accumulates More Rapidly Within the Body Than Previously Thought

ScienceDaily

Tuesday, June 7, 2011

ScienceDaily (June 7, 2011) — A new University of Missouri study shows that the exposure to the controversial chemical Bisphenol A (BPA) through diet has been underestimated by previous lab tests. In the study, researchers compared BPA concentrations in mice that were given a steady diet supplemented with BPA throughout the day, compared to the more common lab method of single exposure, and found an increased absorption and accumulation of BPA in the blood of mice.

This is the first study to examine concentrations of BPA in any animal models after exposure through a regular, daily diet, which is a better method to mirror the chronic and continuous exposure to BPA that occurs in animals and humans. Cheryl Rosenfeld, associate professor in biomedical sciences and Bond Life Sciences investigator, is the corresponding lead author of the study published in Environmental Health Perspectives on June 6.

The authors continuously exposed the mice to BPA through their feed, which is considered the primary route of exposure to this chemical in animals and humans. In previous studies examining the effects of BPA, mice were exposed to BPA only through a one-time administration. Following the exposure through the diet, a significantly greater increase in the active form of BPA, which is the greatest threat as it is the form that can bind to sex steroid receptors and exert adverse effects, was absorbed and accumulated in the animals.

"People are primarily and unknowingly exposed to BPA through the diet because of the various plastic and paper containers used to store our food are formulated with BPA," Rosenfeld said. "We know that the active form of BPA binds to our steroid receptors, meaning it can affect estrogen, thyroid and testosterone function. It might also cause genetic mutations. Thus, this chemical can hinder our ability to reproduce and possibly cause behavioral abnormalities that we are just beginning to understand."

The study notes that more than 8 billion pounds of BPA are produced every year, and more than 90 percent of people in the United States have measurable amounts of BPA in their bodies.

"We believe that these mouse model studies where the BPA exposure is through the diet is a more accurate representation of what happens to BPA as the human body attempts to processes this toxic substance," said Rosenfeld. "When BPA is taken through the food, the active form may remain in the body for a longer period of time than when it is provided through a single treatment, which does not reflect the continuous exposure that occurs in animal and human populations. We need to study this further to determine where the ingested BPA becomes concentrated and subsequently released back into the bloodstream to be distributed throughout the body."

Funding from this study came from a National Institute of Environmental Health and Sciences challenge grant program that was established to investigate the biological effects of exposure to BPA.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Journal Reference:

Paizlee T. Sieli, Eldin Jašarević, Denise A. Warzak, Jiude Mao, Mark R. Ellersieck, Chunyang Liao, Kurunthachalam Kannan, Séverine H. Collet, Pierre-Louis Toutain, Frederick S. vom Saal, Cheryl S. Rosenfeld. Comparison of Serum Bisphenol A Concentrations in Mice Exposed to Bisphenol A through the Diet Versus Oral Bolus Exposure. Environmental Health Perspectives, 2011; DOI: 10.1289/ehp.1003385

Chronic Pot Smoking Affects Brain Chemistry, Scans Show

HealthDay News

Tuesday, June 7, 2011

TUESDAY, June 7 (HealthDay News) -- Imaging scans show that chronic daily use of marijuana can have a detrimental effect on the brain, according to a new report.

In the study, researchers revealed that chronic use of the drug caused a decrease in the number of receptors involved in a wide array of important mental and bodily functions, including concentration, movement coordination, pleasure, pain tolerance, memory and appetite.

Marijuana, also known as cannabis, is abused more than any other illegal drug in America, according to the U.S. National Institute on Drug Abuse. When smoked or ingested, the drug's psychoactive chemical binds to numerous cannabinoid receptors in the brain and throughout the body, which influence a range of mental states and actions. One of two known types of cannabinoid receptors, called CB1, is involved primarily in the central nervous system.

In conducting the study, researchers compared the brains of 30 chronic daily marijuana smokers to non-smokers over the course of roughly four weeks. Using molecular imaging, researchers were able to visualize changes in the participants' brains and found the cannabinoid CB1 receptors of the smokers had decreased by roughly 20 percent compared to the otherwise healthy people with limited lifetime exposure to marijuana.

"With this study, we were able to show for the first time that people who abuse cannabis have abnormalities of the cannabinoid receptors in the brain," lead author Dr. Jussi Hirvonen said in a Society of Nuclear Medicine news release.

The researchers re-scanned 14 of the smokers after one month of abstinence and found a notable increase in receptor activity in areas that were deficient at the beginning of the study. These findings, the investigators concluded, suggest the adverse effects of chronic marijuana use are reversible.

"This information may prove critical for the development of novel treatments for cannabis abuse. Furthermore, this research shows that the decreased receptors in people who abuse cannabis return to normal when they stop smoking the drug," Hirvonen added.

The study, which was a collaboration between the U.S. National Institute of Mental Health and U.S. National Institute on Drug Abuse, was slated for presentation Monday at the annual meeting of the Society of Nuclear Medicine in San Antonio, Texas. Because this study was presented at a medical meeting, the data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.

More information

The U.S. National Institute on Drug Abuse has more on marijuana and its effects on the brain.

High Amounts of the Hormone Leptin Are Linked to Decreased Depression

ScienceDaily

Tuesday, June 7, 2011

ScienceDaily (June 7, 2011) — Women who have higher levels of the appetite-controlling hormone leptin have fewer symptoms of depression, and this apparent inverse relationship is not related to body mass index (BMI), a new study finds.

The results are being presented at The Endocrine Society's 93rd Annual Meeting in Boston.

"Animal data suggest that leptin may reduce anxiety and improve depression. Our study in women suggests that leptin may indeed have antidepressant qualities," said the study's lead author, Elizabeth Lawson, MD, of Massachusetts General Hospital and Harvard Medical School in Boston.

Leptin, the product of fat cells, signals satiety, or fullness. It is low in thin women and high in obese women, according to Lawson. She also said there is an increased prevalence of anxiety and depression in certain conditions in which leptin levels are typically low. These include the eating disorder anorexia nervosa, in which there is abnormally low weight and body fat, and functional hypothalamic amenorrhea, in which women have stopped menstruating despite having normal weight.

"It is unknown whether low leptin levels contribute to the development of mood disorders in these women," Lawson said.

She and her co-workers studied the relationship between leptin levels and symptoms of anxiety and depression in 64 women. Fifteen of the women had anorexia nervosa, 12 were normal weight with hypothalamic amenorrhea, 20 were normal weight and in good health, and 17 were overweight or obese but still healthy.

All subjects were asked questions to assess symptoms of depression and anxiety, with high scores indicating more symptoms. Besides measuring leptin levels in the blood, the researchers assessed the women's BMI, a measure of weight for height.

They found that higher leptin levels were linked to decreased symptoms of anxiety and depression. The relationship between leptin and depression symptoms was independent of BMI. This finding indicates that leptin may mediate symptoms of depression and that this effect is not a function of low weight, Lawson said.

"Further research administering leptin to humans will be important in understanding whether this hormone has a potential role in the treatment of depression," she said.

The current study received funding from Bioenvision in New York City and from the National Institutes of Health.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Childhood Cancer Survivors at Greater Risk for Tumors as Adults

HealthDay News

Tuesday, June 7, 2011

TUESDAY, June 7 (HealthDay News) -- Children who survive cancer are more likely to develop another tumor later in life, a new study of nearly 18,000 cancer survivors found.

Researchers followed 17,981 cancer survivors who were first diagnosed before the age of 15 over 25 years. During that time, 1,354 new tumors (neoplasms) were found in 1,222 of the survivors. The most common tumors, the study revealed, involved the central nervous system, followed by non-melanoma skin cancer.

Overall, researchers concluded survivors were four times more likely than expected to develop another tumor later in life.

In adults older than 40, the greatest additional risk was for a new tumor -- either malignant or benign -- of the digestive, genital or urinary tract organs, researchers found.

Survivors were more likely to develop a subsequent tumor as they grew older -- from 1.6 percent at age 20 to 13.8 percent at age 60 (compared to just 8.4 percent of 60-year-olds in the general population.)

The survivors were also at increased risk of developing a tumor at younger ages. By age 38, 5 percent of the childhood cancer survivors had developed a new tumor. For a group drawn from the general population, it would take until age 54 for 5 percent to develop a tumor.

The researchers also found that 1.4 percent of those studied whose childhood cancer was treated with direct irradiation near their abdominal and pelvic region developed colorectal cancer by the time they were 50 years old -- roughly the same risk as people who have at least two first-degree relatives with this disease.

"These increased risks of digestive subsequent [tumors] are likely to be related to previous exposure of the digestive tract to radiation," according to the study's authors. They concluded there may be a need for childhood cancer survivors treated with direct abdomino-pelvic irradiation to be considered for routine colonoscopy screening for colorectal cancer.

The researchers added, however, genetic predisposition is also at least partly to blame for the added tumor risk in childhood cancer survivors. The study, published in the June 8 issue of theJAMA, also noted that the magnitude of the risk in the aging process is still unclear.

More information

The National Cancer Institute provides detailed information on current trends in childhood cancer.

Monday, June 6, 2011

Smokers show higher risk of leg artery disease

By Amy Norton

Reuters Health

Monday, June 6, 2011

NEW YORK (Reuters Health) – Women who smoke are much more likely than non-smokers to develop clogged arteries in the legs -- but quitting can lower those odds, according to a study published Monday.

The study, reported in the Annals of Internal Medicine, found that female smokers were up to 17 times more likely than non-smokers to develop peripheral artery disease (PAD).

About 8 million Americans have PAD, which usually arises when atherosclerosis, a hardening and narrowing of the arteries, restricts blood flow to the legs. The main symptom is leg pain or cramps during normal activities, like walking, though not everyone with the condition has symptoms.

People with PAD often have widespread atherosclerosis, including coronary heart disease -- where arteries feeding the heart become narrowed and stiff. For some, leg pain is the first symptom of wider problems.

Smoking has a well-established link to heart disease. But fewer studies have focused on PAD.

The good news from the current study is that women who kicked the habit appeared to lower their risk of PAD -- though they did not eliminate it.

"Our most important finding, in my view, is that smoking cessation substantially reduces this risk," said lead researcher Dr. David Conen, of the University Hospital Basel in Switzerland.

"We found a gradual decrease in risk with an increased duration of smoking abstinence, highlighting the importance of smoking cessation," Conen told Reuters Health in an email.

Compared with lifelong non-smokers, former smokers had three times the risk of developing PAD over 13 years.

But current smokers showed much higher odds: those who smoked fewer than 15 cigarettes a day had a nine-fold higher risk of PAD than lifelong non-smokers, while those who lit up more often had a 17-times higher risk.

"Clearly, our study adds one more reason to quit smoking as soon as possible," Conen said.

However, he added, "the fact that the risk of PAD does not get down to that of women who never smoked also emphasizes the importance that never starting smoking is at least as important."

The findings come from a long-running study of U.S. women who were age 45 or older and free of heart disease and other major health problems at the outset. Of nearly 40,000 women followed for 13 years, 178 were eventually diagnosed with PAD.

Among the heaviest smokers -- 15 or more cigarettes per day -- PAD was diagnosed at a rate of 1.6 cases for every 1,000 women each year. Among lifelong non-smokers, there were 0.1 cases for every 1,000 women each year.

When Conen's team accounted for other PAD risk factors, like older age, obesity and diabetes, smoking itself was still strongly linked to the disease.

The researchers also gained some clues as to why smoking might lead to PAD. Based on blood samples from a subgroup of women, high levels of certain inflammatory proteins accounted for some of the risk linked to smoking.

That, Conen's team says, suggests that smoking leads to PAD, in part, by spurring chronic inflammation in the blood vessels.

He suggested that doctors be careful to look for signs and symptoms of PAD in patients who smoke.

Besides leg pain during exercise, other signs include leg sores that don't heal, feelings of cold or numbness in the legs or feet, and hair loss or slowed hair growth on the legs.

Once PAD is diagnosed, treatment usually involves lifestyle changes to improve a person's overall cardiovascular health, including a healthy diet and regular exercise. People with PAD may also take aspirin or other medications to prevent blood clots.

In cases where leg pain is debilitating, doctors may prescribe medications that improve blood flow to the legs. Some people end up needing angioplasty or bypass surgery to take care of blockages in the leg arteries.

Source: http://bit.ly/an7XRm

Annals of Internal Medicine, June 7, 2011.

Supplement Found to Improve Quality of Life for Female Cancer Survivors

ScienceDaily

Monday, June 6, 2011

ScienceDaily (June 6, 2011) — A natural nutritional supplement, marketed for the last decade as a sexual aid, has been shown to significantly improve overall quality of life for female cancer survivors, according to researchers at Wake Forest Baptist Medical Center.

The findings will be presented June 6 at the 2011 American Society of Clinical Oncology (ASCO) annual meeting in Chicago.

Interested in quality of life issues for female cancer survivors, Kathryn M. Greven, M.D., a radiation oncologist at Wake Forest Baptist, first learned of the supplement, called ArginMax for WomenTM, from a small study conducted at Stanford University that found that it improved sexual function. Sexual dysfunction is prevalent in female cancer survivors, so Greven set out to see if the supplement could produce the same benefit in this population. She found that, while taking the supplement did not result in any improvement in sexual function for female cancer survivors, the supplement did improve their overall quality of life.

With funding from the National Cancer Institute, researchers at the Comprehensive Cancer Center at Wake Forest Baptist, the Derrick L. Davis Forsyth Regional Cancer Center, and multiple other cancer centers across the country recruited 186 female cancer survivors to participate in the study.

To be considered, adult female volunteers had to be at least six months beyond their last active treatment for any kind of cancer, with no current evidence of cancer. Adhering to standard double-blind, placebo-controlled protocol, neither the participants nor the investigators knew who was receiving the supplement and who was receiving a placebo.

The Daily Wellness Company, based in Honolulu, Hawaii, provided materials for the study, including ArginMaxTM and placebo pills. Participants received three capsules of either ArginMaxTM or placebo twice a day for 12 weeks and were asked to complete two standardized questionnaires that accurately measure sexual function and quality of life. The questionnaires were completed at the start of the study, at four weeks, eight weeks and 12 weeks.

The Female Sexual Function Index is a questionnaire that measures different aspects of sexual function, such as desire, arousal, lubrication, orgasm, satisfaction and pain.

The FACT-G questionnaire measures overall quality of life and has been used in research of all cancer types. It evaluates physical, emotional, social and functional well-being.

ArginMaxTM was originally designed as a sexual enhancement aid, so researchers were primarily looking for improvements in sexual function in this new population. They found no benefit in this area.

However, the study findings did reveal an across-the-board boost in measures of overall quality of life for the patients who were randomized to take ArginMaxTM. The FACT-G questionnaires showed improvements in both physical and functional well being among the participants taking the supplement.

"The group taking the supplements experienced significant improvement in overall quality of life, particularly physical well-being," said Greven, the lead investigator on the study. "Bothersome symptoms such as lack of energy, pain, nausea, and sleeplessness were all improved, as were measures of functional well-being, for example the ability to perform normal activities at home or work. Simply, they reported a greater enjoyment of life, without any additional side effects from the supplement."

Edward G. Shaw, M.D., M.A., an oncologist as well as counselor, is principal investigator for Wake Forest Baptist's Community Clinical Oncology Program Research Base and a co-researcher on the study. He explained that cancer survivors can suffer from persistent inflammation, also known as chronic oxidative stress, that can continue for years following treatment of cancer causing fatigue that affects quality of life. He hypothesized that the ingredients in ArginMax for WomenTM may be helping to counteract this process.

ArginMaxTM is made from a patented formula containing a proprietary blend of L-arginine, ginseng, ginkgo, and 14 vitamins and minerals noted for boosting energy and circulation and optimizing hormonal balance. A separate Men's formula also is available.

"Beyond managing individual symptoms as they appear, the medical community has not been able to offer cancer patients more global symptom relief," he said. "This research is empowering for the community of cancer survivors. There's been some thought that dietary supplements could offer a potential benefit, but previous studies on other drugs and supplements have had disappointing outcomes. We'd like to see the results replicated in other studies, as they give us renewed hope in this area."

Greven said the findings have sparked interest among researchers about whether the supplement could improve quality of life and energy levels for other populations, as well. Future studies are being planned.

"It is very exciting that we've found something that has the potential to affect and improve quality of life for female cancer survivors," Greven said. "We still need to do further work to find an approach that will improve female sexual dysfunction."

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Exercise Helps Men Battling Diabetes and Sleep Apnea

HealthDay News

Monday, June 6, 2011

MONDAY, June 6 (HealthDay News) -- Men who have type 2 diabetes in addition to obstructive sleep apnea seem to benefit from a regular exercise regimen, a new study has found.

Greater endurance from consistent physical activity can significantly boost survival rates for men with both conditions, researchers found. The findings are significant since the prevalence of sleep apnea, which commonly occurs in people with diabetes and high blood pressure, is on the rise, the study authors noted.

"Recent findings suggest that patients with sleep apnea have an increased risk of dying of any cause compared with individuals without sleep apnea," study co-author Dr. Skikha Khosla, an endocrinologist at the Washington, D.C. Veterans Affairs Medical Center and George Washington University, said in a news release from the Endocrine Society.

Good exercise capacity has already been linked to a lower risk of death in patients with type 2 diabetes, Khosla added. The new study, slated to be presented Monday at the Endocrine Society's annual meeting in Boston, found that there is a similar relationship in men who also have obstructive sleep apnea, a disorder that disrupts breathing during sleep.

For the study, researchers analyzed 567 male veterans averaging 62 years of age who completed exercise fitness testing between 1996 and 2010. The men's fitness levels were based on the number of peak metabolic equivalents (METs) they achieved during a stress test (a test that determines how well the heart handles exertion). Men who earned 5 or fewer METs were classified as low fitness. Those who earned more than 10 METs were considered high fitness, and anyone in between was graded as moderate.

After taking other risk factors into account, such as race, smoking and medication use, the researchers found that the risk of death among the men was 13 percent lower for every 1-MET increase in fitness level. Moreover, men in the low-fitness category had a 75 percent higher risk of death than those considered high fitness.

"Although these data are epidemiologic and our patient population was small, the trend we saw in mortality is impressive," said Khosla. She added, however, that more studies are needed to confirm the results.

Although people with sleep apnea should strive to get 150 to 200 minutes of physical activity each week, they should talk to their doctor before starting any exercise program and work towards that goal gradually, Khosla advised.

Because this study was presented at a medical meeting, the data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.

More information

The National Sleep Foundation has more on the connection between sleep apnea and exercise.

Leucine Deprivation Proves Deadly to Malignant Melanoma Cells

ScienceDaily

Monday, June 6, 2011

ScienceDaily (June 6, 2011) — Whitehead Institute researchers have found that depriving human melanoma cells of the essential amino acid leucine can be lethal to the cells, suggesting a possible strategy for therapeutic intervention.

T he researchers observed the effect in melanoma cells with a mutation in the RAS/MEK signaling pathway -- the most common mutation found in the deadliest form of skin cancer.

Leucine is one of nine essential amino acids humans must ingest, as we are unable to synthesize them. These nine, along with 12 non-essential amino acids, are the building blocks of proteins used in muscle production and normal cell functions. Cellular amino acid levels and other nutrients are monitored by the mTOR pathway. Typically, when levels of one or more amino acids drop too low, the mTOR pathway is turned off, which activates a process called autophagy.

During autophagy, the cell attempts to boost amino acid levels by breaking down the cell's protein-based structures back into their amino acid components. This is similar to the entire body breaking down fat and muscle when it is on a diet. For a cell, autophagy is a short-term survival mechanism.

According to their paper published in the May 17 issue of Cancer Cell, researchers in the lab of Whitehead Institute Member David Sabatini found that melanoma cells with RAS/MEK pathway mutations short-circuit this chain of events.

"The odd thing is that if you remove this one essential amino acid, leucine, the melanoma cells don't activate autophagy," says Sabatini, who is also a professor of biology at MIT and a Howard Hughes Medical Institute (HHMI) investigator. "Because leucine is essential, they eventually die. Potentially, that could be used as a way of targeting the melanoma cells if one could mimic the lack of leucine."

When melanoma cells with RAS/MEK pathway mutations are deprived of leucine, mTOR does not sense it, so mTOR does not turn off, and autophagy never begins. Instead, the cells behave as if there were no nutrient shortage until they reach a metabolic crisis and die.

Although cells in a test tube can be deprived of leucine completely, removing leucine from a mouse or a human is almost impossible, due to large leucine reservoirs in muscles. To test how leucine deprivation works in an animal model, Joon-Ho Sheen, who is first author of the Cancer Cell paper, implanted human melanoma tumors with RAS/MEK pathway mutations into mice. He then fed the mice a leucine-free diet. Within a few days, the leucine concentration in the mice's blood dropped from about 110 micromoles to 60 or 70 micromoles. As the blood leucine levels dropped, so too did the leucine levels within the mice's cells. Still, the drop in leucine wasn't sufficient to kill the melanoma cells in vivo.

Sheen then gave the mice the drug chloroquine along with a leucine-free diet. Chloroquine, which is an anti-malaria drug, inhibits autophagy. With the one-two punch of chloroquine and a leucine-free diet, the melanoma cells died, significantly reducing tumor sizes compared with mice fed either a normal diet or a leucine-free diet without chloroquine.

For Sheen, these results raised more questions, particularly with regard to potential therapeutic applications.

"Thanks to the pioneering work by others in the autophagy field, we were able to show that leucine deprivation triggers apoptosis in melanoma cells. I think our work provides a framework, but there are many areas to fill in," says Sheen, who is a postdoctoral researcher in the Sabatini lab. "In practice, how can you deprive just leucine in humans? Maybe using some sort of enzyme that degrades leucine or a small molecule inhibitor that blocks leucine's uptake by cells. And we need a better way to target autophagy; chloroquine isn't very efficient at this. And those are just the immediate, foreseeable issues."

This research was supported by the National Institutes of Health (NIH), the U.S. Department of Defense (DoD), the Jane Coffin Childs Memorial Fund for Medical Research, and the American Brain Tumor Association.

David Sabatini's primary affiliation is with Whitehead Institute for Biomedical Research, where his laboratory is located and all his research is conducted. He is also a Howard Hughes Medical Institute investigator and a professor of biology at Massachusetts Institute of Technology.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Journal Reference:

Joon-Ho Sheen, Roberto Zoncu, Dohoon Kim, David M. Sabatini. Defective regulation of autophagy upon leucine deprivation reveals a targetable liability of human melanoma cells in vitro and in vivo. Cancer Cell, Volume 19, Issue 5, 613-628, 17 May 2011 DOI: 10.1016/j.ccr.2011.03.012

Ovarian cancer screening doesn't save lives: study

By Genevra Pittman

Reuters Health

Monday, June 6, 2011

NEW YORK (Reuters Health) – Women screened annually for ovarian cancer were just as likely to die from the disease as women who didn't have regular screening, concludes a large new study that found screening did not catch the cancers earlier as it is intended to do.

Calling into question the effectiveness of current ovarian cancer screening techniques, the researchers also found that more of the women screened annually had surgery to remove their ovaries and suffered complications related to false-positive test results -- meaning a screening test suggested they had ovarian cancer when they really didn't.

The finding is in line with other recent research that suggests annual screening doesn't prevent deaths from the disease, which kills most women within 5 years of their diagnosis (see Reuters story of May 18, 2011.)

According to the National Cancer Institute, 1 in 72 women will get ovarian cancer. But symptoms usually don't start until the cancer has spread, so most women who are diagnosed already have an advanced stage of the disease that is harder to treat.

Doctors have hoped that screening women regularly could help catch ovarian cancer earlier, when patients have a better long-term outlook.

"We know with ovarian cancer that when the disease is detected in stage 1 you can have 85-90 percent 5-year survival," said Dr. Christine Berg, one of the new study's authors from the National Institutes of Health. "The question is, can you detect the cancers that are destined on to be stage 3 or unfortunately stage 4 at an early enough stage that you can intervene?"

The current study was part of a larger trial looking at the effectiveness of screening for prostate, lung, colorectal and ovarian cancers. Berg and her colleagues randomly split almost 70,000 women into two roughly equal-sized groups -- one that got yearly screening for ovarian cancer between 1993 and 2001, with both blood tests and ultrasounds, and one that didn't.

The researchers then followed women in both groups until 2010, through questionnaires and a national registry of deaths, to see how many were diagnosed with ovarian cancer and how many died of the disease.

Out of about 34,000 women in each group, 212 women in the screening group were diagnosed with ovarian cancer, and 118 of them died from the disease. That compared to 176 diagnoses and 100 deaths in the group that didn't get regular screening.

Also in both groups, more than three-quarters of women who were diagnosed with ovarian cancer already had stage 3 or 4 disease.

The results are published in the Journal of the American Medical Association, and were presented last weekend at the American Society of Clinical Oncology annual meeting in Chicago.

Berg's team also recorded more than 3,000 cases of false-positives in the screening group, and of those, more than 1,000 women who didn't end up having ovarian cancer had surgery to remove an ovary because of a positive test result. Those surgeries resulted in serious complications, including infection or cardiovascular complications, in 163 women.

"Many people will say, 'Oh it's just a blood test, oh it's just an ultrasound, what's the harm?'" Berg told Reuters Health. "The harm is you might have unnecessary surgery that could hurt you."

The combination of blood tests and ultrasounds that her team tested "shouldn't be used for screening in the average-risk woman," she said. "I don't think it's working at all."

Berg said that it's possible that a modified form of the blood test -- which looks for a protein that hints at the presence of ovarian cancer cells - will help doctors identify early cases of ovarian cancer. But she said that researchers need to understand more about how ovarian cancers grow and spread to find the best early detection strategy.

"In the meantime," Berg added, "I think women who are high risk for ovarian cancer based on family history of the disease or a personal history of breast cancer -- they should see a specialist...to consider being tested for genes that predispose to ovarian cancer. But for the normal-risk woman, I don't think we have a screening strategy."

The U.S. Preventive Services Task Force, a federally supported expert panel, also recommends against routine screening for ovarian cancer.

Source: http://bit.ly/jxhmC9

JAMA, online June 4, 2011.

Yo-Yo Dieting Vs. Obesity? Dieters May Be Healthier, Live Longer, Mouse Study Suggests

ScienceDaily

Monday, June 6, 2011

ScienceDaily (June 6, 2011) — Yo-yo dieters may be healthier and live longer than those who stay obese, a new Ohio University study in mice suggests.

Mice that switched between a high-fat and low-fat diet every four weeks during their approximate two-year lifespan lived about 25 percent longer and had better blood glucose levels than obese animals that ate a high-fat diet. The yo-yo dieters also lived about as long as a control group of mice steadily fed a low-fat diet.

Some experts argue that constantly shedding and regaining pounds can be harmful to health. The new research, presented at the annual meeting of the Endocrine Society in Boston, suggests, however, that yo-yo dieting is preferable to remaining obese and not dieting at all.

"If the conventional wisdom is true, it would discourage a lot of overweight people from losing weight," said study lead author Edward List, a scientist at Ohio University's Edison Biotechnology Institute. "The new research shows that the simple act of gaining and losing weight does not seem detrimental to lifespan."

About 34 percent of American adults are considered to be obese; an additional 34 percent are classified as overweight, according to the Centers for Disease Control and Prevention. Although millions of Americans diet each year, research has shown that few people maintain long-term weight loss.

In the first study on yo-yo dieting of its kind, List and colleagues followed 30 mice on one of three dietary regimens over the course of a little over two years, the typical lifespan of this particular strain of laboratory mouse. The animals on the high-fat diet ate more, weighed more and had higher levels of body fat and fasting blood glucose. They also become glucose intolerant, or pre-diabetic, said List, whose research is supported by the National Institutes of Health, AMVETS and Ohio University.

The health profile of the mice on the yo-yo diet declined during their high-fat food phases, but their weight and blood glucose levels returned to normal levels during their low-fat diet stages. Lifespan -- the "gold standard" for lifelong health status -- was 2.04 years for the yo-yo dieting mice, compared to 1.5 years for the obese mice. The control group lived, on average, for 2.09 years.

Although replicating the research in humans is ideal, List said, it would be challenging to pursue a long-term controlled diet study. Various factors, including illness, can impact weight cycling. Mice can serve as a good model for obesity research, he noted, as they allow researchers to follow the effects of diet choices on lifespan over a relatively short time period.

"The study adds to our understanding of the benefit of losing weight," he said. "I would hope that this encourages people to not give up."

List plans to expand the study to a larger population of mice. He'll also further examine preliminary findings that suggest that the yo-yo dieting animals experienced a reduction in cytokine levels. High levels of cytokine are linked to increased inflammation, which is associated with diseases such as diabetes, heart disease and cancer.

Co-authors of the study are former Ohio University student Jacob Wright-Piekarski, now a medical student with St. Louis University, and Edison Biotechnology Institute scientists Darlene Berryman, an associate professor in the College of Health Sciences and Professions, and John Kopchick, Goll-Ohio Eminent Scholar of molecular biology in the College of Osteopathic Medicine.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Sunday, June 5, 2011

Flaxseed Fails as Treatment for Hot Flashes

By Amanda Gardner
HealthDay Reporter

HealthDay News

Sunday, June 5, 2011

SUNDAY, June 5 (HealthDay News) -- The search for a safe remedy for menopausal hot flashes has been foiled again, with flaxseed the latest in a long line of compounds that apparently don't reduce the incidence of the unpleasant symptoms.

Researchers presenting a new study Sunday at the annual meeting of the American Society of Clinical Oncology in Chicago report that a daily flaxseed bar was no more effective than a placebo in helping with hot flashes in women with or without breast cancer.

"It's unfortunate because these are such common problems, not just in breast cancer survivors but in postmenopausal women in general," said Dr. Joanne E. Mortimer, director of women's cancers programs at City of Hope Cancer Center in Duarte, Calif. "These poor women have one less option." Mortimer was not involved with the study.

Hot flashes often occur in breast cancer patients who have undergone hormonal treatment for their tumors as well as in women going through normal menopause.

"Women who are taking endocrine [hormone] therapy and have significant side effects may be less likely to be adherent to treatment, and that leads to worse outcomes," said Dr. Erica L. Mayer, a breast oncologist with Dana Farber Cancer Institute in Boston, who also was not involved with the new research.

Estrogen therapy has been shown to be effective in reducing the incidence of hot flashes but not without a hefty health cost, including a heightened risk of stroke and blood clots.

Flaxseed contains lignans, which can work against estrogen.

"Anecdotally it [flaxseed] has been thought to improve hot flashes and they [the researchers behind the new study] had some pilot data from a non-randomized trial that women who took flaxseed had decreased hot flashes," said Mayer. "That led to the current trial."

For the new study, almost 200 postmenopausal women who reported having at least 28 hot flashes a week were randomly selected to receive either a placebo or a daily flaxseed bar for six weeks.

About half of the women had had breast cancer and half had not.

Although both groups of women reported declines in the number of hot flashes they were experiencing, that number was about the same in each group, with about a third in each group reporting a 50 percent reduction in symptoms.

There were also side effects in both groups, namely bloating, diarrhea and nausea, most likely due to the fiber in the placebo and flaxseed bars, said study author Sandhya Pruthi, an associate professor of medicine at the Mayo Clinic in Rochester, Minn.

"This is a much more complex brain process that we need to understand," said Mortimer. "Negative studies like this [should] spur us on to find the biological mechanisms behind this [hot flashes]. Right now, we don't even know the mechanisms."

Various antidepressants such as Effexor and Zoloft have been shown to be effective against hot flashes, as has acupuncture, said Mayer.

Still, she added, "This is a disappointing study in that it didn't confirm what we had previously seen, but it supports further high-quality, ongoing research to identify agents which are well-tolerated, acceptable to patients and effective in reducing hot flashes so they can stay on therapy and have better breast cancer outcomes."

More information

The U.S. National Library of Medicine has more on menopause.