Personal Health

 

 

Friday, March 18, 2011

Heart disease screens don't change treatment

By Frederik Joelving

Reuters Health

Friday, March 18, 2011

NEW YORK (Reuters Health) – If you don't have signs of heart disease, there is no evidence to suggest that getting heart tests like CT scans or echocardiography will do you much good, researchers say.

"It is shocking how little evidence there is," Dr. Patrick O'Malley of the Uniformed Services University in Bethesda, Maryland, who wrote an editorial in the Archives of Internal Medicine, where the new report was published.

Looking at earlier studies, the authors found screening people with such tests didn't seem to change what drugs doctors prescribed, nor the patients' diet and exercise habits or whether they smoked.

These are all factors that could influence a person's risk of heart disease, which accounts for more than one out of every three deaths in the U.S., according to the American Heart Association.

The hope is that taking a piercing look at the heart will spot problems like calcium buildups that might one day block its blood supply. In principle, that would allow patients and their doctors to take steps to avert heart attacks, strokes and similar conditions down the road.

CT scans may cost anywhere between a few hundred dollars to a couple of thousand, and expose patients to radiation. But like other tests for heart disease, they have never been proven to improve health in patients without symptoms.

Still, the number of Americans who get these tests has been climbing fast in recent years. Every year, for instance, hundreds of thousands of people get CT scans, an imaging technique based high-dose x-rays. No one knows how many of those are done to look for heart problems in patients who don't have any symptoms.

O'Malley said the tests shouldn't be used on people without chest pain and other symptoms of heart disease outside of clinical experiments.

The report is based on a review of seven earlier studies -- all the authors could find -- that tested whether heart imaging had an impact on people's lifestyle and the treatment they got.

The original studies included a broad swath of people without symptoms of heart disease -- some had major risk factors like diabetes and some were healthy middle-aged people.

Across the board, Dr. Daniel Hackam of the University of Western Ontario in London, Canada, and colleagues found no differences between those who had their heart tested and those who didn't.

But they add the studies were so small -- most included only a few hundred individuals -- that a possible impact couldn't be entirely ruled out.

Along with CT, or computed tomography, researchers also looked at screening with echocardiography, ultrasound, and so-called myocardial perfusion imaging.

None of those tests are recommended for screening purposes by the U.S. Preventive Services Task Force, a federal task force. On the other hand, several medical societies, including the American Heart Association, support their use.

Dr. Allen Taylor, a cardiologist at Georgetown University in Washington, D.C., who wasn't involved in the new work, said the findings didn't mean the tests are no good.

"All you can conclude from that paper is we need some better evidence," he told Reuters Health. "Innovation will stop if there is an irrational demand for evidence beyond refute."

"It's completely about the way information is identified by clinicians and put into practice," he added. "The guidelines are not as clear and that's a gap."

Taylor, who said he has no ties to manufacturers of imaging equipment, explained the tests give a better idea of a patient's risk than traditional risk factors like blood pressure and obesity.

But other experts disagree about their usefulness.

"You get more false information than you get real information," Dr. Rita F. Redberg, a cardiologist at the University of California, San Francisco, told Reuters Health last year.

Source: http://bit.ly/g62O3V

Archives of Internal Medicine, online March 14, 2011.

Resveratrol May Be Useful Tool for Reducing Body Fat

ScienceDaily

Friday, March 18, 2011

ScienceDaily (Mar. 18, 2011) — For her thesis entitled Conjugated Linoleic Acid and Resveratrol: the effect of these functional ingredients on the metabolism of triglycerides and adiposity, nutrition and obesity research team member at the University of the Basque Country (UPV/EHU), Ms Arrate Lasa, studied the fat-reducing effect of CLA and resveratrol.

Obesity is a very common illness in developed countries, there being more than 1,000 million overweight persons currently in the world, of which more than 300 million suffer from obesity. This illness brings with it other, associated conditions that result in a significant increase in the morbi-mortality of these persons.

Current strategies for its treatment are various and one field of great interest is what is known as functional ingredients. These are compounds that appear in certain foods and that enhance specific corporal functions, promoting health and reducing risk of diseases.

Fat reduction with functional ingredients

Conjugated Linoleic Acid (CLA) and resveratrol are two functional ingredients that, in various experiments on living beings and in vitro, have proved to have a fat-reducing effect. On the one hand, the properties attributed to CLA indicate that it prevents weight gain and the accumulation of body fat, through inhibiting the synthesis of fat and increasing the oxidation of fatty acids. However, its effects when applied in a hypocaloric diet – for the treatment of obesity – are unknown. On the other, it is known that resveratrol has hypolipemiant properties, but its effect on the use of accumulated fat has not been extensively analysed.

This thesis shows, on the one hand, the results obtained after treatment with CLA in hamsters subjected to energy restriction and, on the other, the effect of resveratrol on accumulated fat and lipolytic activity in cell cultures of adipocytes of murinae and humans. The results obtained show that CLA does not foment weight or body fat loss, induced by an energy restriction diet. Neither does it induce greater lipolysis, nor improvement in serum parameters, in glucose homeostasis or insulin function to any greater extent than with the slimming diet itself. On the contrary, resveratrol reduces the accumulation of triglycerides, in part by activation of lipolysis, in both the adipocytes of mice and of humans.

For all these reasons, it can be concluded that, while CLA may not be a molecule useful in treating obesity, when resveratrol is included in hypocaloric diet, it could well be a useful tool for reducing body fat. More studies are required regarding this latter molecule, firstly to describe other effects of resveratrol and its activating mechanisms, as well as the possible adverse effects and toxicity; secondly studies amongst humans confirm the previously observed effects.

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.

Drug resistance hampers fight against tuberculosis

By Kate Kelland

Reuters

Friday, March 18, 2011

LONDON (Reuters) – Rising rates of multi-drug resistant tuberculosis (TB) are hampering world health programs aimed at tackling TB and threaten to wipe out progress made against the disease, scientists said on Friday.

Experts from the World Health Organization and the European Center for Disease Prevention and Control (ECDC) said they were concerned about spreading multidrug-resistant TB, known as MDR TB, in Europe, and the persistence of TB among children.

A second report, in The Lancet medical journal, said sub-Saharan Africa was disproportionately affected and accounted for four of every five cases of tuberculosis linked to HIV, the human immunodeficiency virus that causes AIDS.

"Increasing rates of drug-resistant TB in eastern Europe, Asia, and sub-Saharan Africa now threaten to undermine the gains made by worldwide tuberculosis control programs," said researchers in The Lancet.

TB kills an estimated 1.7 million people each year and the worldwide number of new cases -- more than 9 million -- is higher than at any other time in history, they said.

According to data from the WHO's European office, reported rates of TB have been falling in Europe since 2005 with a regional average of 36.8 notifications per 100,000 population in 2009. But notification rates of newly detected and relapsed TB cases in 18 high-priority countries remain almost eight times higher than in the rest of the region, the WHO data show.

"Vulnerable populations, including children, still do not have ready access to quality and timely diagnosis and treatment," the WHO-ECDC report said. "This remains a matter of urgency given the high prevalence of multi- and extensively drug-resistant TB in the region.

Up to a third of people worldwide are infected with the bacterium that causes TB, but only a small percentage ever develop the disease. Studies show that people with substance abuse problems, those who are poor and those who live in hard-to-reach communities are more prone to the disease.

The AIDS epidemic drove up the number of TB cases across the world in the late 1980s and 1990s because the immune suppression caused by HIV can make a person far more susceptible to TB.

People can get drug-resistant forms of TB either as a result of catching such a strain from another person or because of inappropriate or incomplete treatment.

In The Lancet report, Alimuddin Zumla of University College London Medical School and Stephen Lawn of the University of Cape Town said rising global rates of diabetes and high rates of smoking in low and middle-income countries were now increasingly important drivers of the TB epidemic.

Diabetes raises the risk of developing TB three-fold and smoking increases it two-fold, they said.

The experts concluded that progress toward controlling TB worldwide was being hampered by an absence of a quick and cheap diagnostic test, the long duration of treatment, the lack of an effective vaccine, rising rates of drug-resistant TB and weak health systems in developing countries.

(Editing by Douglas Hamilton)

Less bladder cancer in frequent painkiller users

By Genevra Pittman

Reuters Health

Friday, March 18, 2011

NEW YORK (Reuters Health) – People who use painkillers such as ibuprofen on a regular basis may be less likely to get bladder cancer, according to a new review.

The researchers found a smaller chance of the cancer in people taking medications called non-steroidal anti-inflammatory drugs, or NSAIDs, more than twice a week. That includes drugs such as naproxen, marketed as Aleve, and ibuprofen, or Advil.

They did not find a reduced risk of bladder cancer in people who regularly took aspirin, also an anti-inflammatory.

"There's quite a lot of (research) showing that NSAIDs do protect against a variety of cancers," Dr. Daniel Djakiew, a cancer researcher at Georgetown University Medical Center in Washington, D.C., told Reuters Health.

The review, which was published in the American Journal of Epidemiology, adds support to previous studies that have suggested that people who take NSAIDs may have a smaller risk of bladder cancer as well as colon cancer and prostate cancer.

It's possible, said Djakiew, who did not participate in the current study, that "people that chronically consume ibuprofen and maybe other NSAIDs may be getting an anti-cancer benefit that they're not aware of."

Bladder cancer is the sixth most common cancer in the U.S. According to the National Cancer Institute, there were about 70,000 new cases diagnosed nationwide in 2010, and close to 15,000 deaths from the disease.

Researchers led by Dr. Sarah Daugherty from the National Institutes of Health combined data from three previous studies. The authors of each of those studies had asked participants how frequently they took different kinds of medications, including aspirin and other NSAIDs, and then tracked how many of them were diagnosed with bladder cancer over the following years.

The studies included a total of more than 500,000 people who were an average of 62 years old at the beginning of the study. Researchers followed them for an average of 7 years.

During that time, about 2,500 people were diagnosed with bladder cancer. More than 4 out of 5 of them were men.

Of people who never took NSAIDs other than aspirin, about 0.54 percent - or 1 in 185 people - developed bladder cancer. In comparison, 0.41 percent of people who took non-aspirin NSAIDs more than twice a week got bladder cancer, or 1 in 244 people.

How often people took aspirin was not linked with how likely they were to get bladder cancer.

Djakiew said there are lots of possible reasons why people who take NSAIDs regularly might be less at risk for bladder cancer. One of those possible explanations, he said, is that inflammation caused by bacteria or a virus, for example, makes the DNA mutations that lead to cancer more likely. By definition, NSAIDs cut down on inflammation, and could therefore reduce the chance of a cancer developing and spreading.

In an email to Reuters Health, Daugherty said that NSAIDs may prevent the growth of bladder cancer cells - and that anti-inflammatories other than aspirin might be better at it than aspirin.

But the study cannot prove that NSAIDs are responsible for lowering the risk of bladder cancer, and the findings don't mean that taking NSAIDs every day is the best choice for everyone. Such drugs have side effects, including ulcers.

"Based on our results, it would be premature to make recommendations to patients" to take NSAIDs, Daugherty said.

Source: http://bit.ly/iklzBs

American Journal of Epidemiology, online March 2, 2011.

Thursday, March 17, 2011

Breastfed Children Do Better at School, Study Suggests

ScienceDaily

Thursday, March 17, 2011

ScienceDaily (Mar. 17, 2011) — Researchers have shown that breastfeeding causes children to do better at school. The research conducted by Oxford University and the Institute for Social and Economic Research, Essex University, found that as little as four weeks of breastfeeding for a newborn baby has a significant effect on brain development, which persists until the child is at least 14 years old.

The researchers matched each breastfed baby with one or more babies who were not breastfed, but who were similar in all other respects. Test scores in reading, writing and mathematics for the children at ages five, seven, 11 and 14 revealed a statistically significant difference between those who had been breastfed as compared with those who had not.

The research is published in a working paper 'The Effect of Breastfeeding on Children's Cognitive Development', which has yet to be peer reviewed.

Breastfeeding is more likely to be practiced by mothers who are of higher social class with a higher IQ. The researchers needed to demonstrate whether the relationship between breastfeeding and brain development was caused by the breastfeeding alone, or whether it was because mothers who breastfeed are likely to have more successful children anyway.

They used a rich dataset from the Avon Longitudinal Study of Parents and Children, which covers 12,000 children born in the early 1990s in the Bristol area. Babies were matched on a huge range of characteristics, including: their sex, gestational age, birth weight, their mother's age and marital status, parents' job status and education, and their home environment. Crucially, the researchers also used the parents' attitudes to breastfeeding as measured before birth.

Co-author Dr Almudena Sevilla-Sanz, from the Department of Economics and the Centre for Time Use Research at Oxford University, said: 'Comparing the test scores of groups of children matched in this way, we are effectively estimating the causal effect of breastfeeding. We find that breastfeeding does have a causal effect on children's cognitive outcomes. The difference is statistically significant across English, maths and science scores, and persists into secondary school. Indeed, there is some evidence that the effect tends to grow over time.

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.

Rat Study Sheds Light on How Alcohol Affects Young Brain

HealthDay News

Thursday, March 17, 2011

THURSDAY, March 17 (HealthDay News) -- Based on the results of a new study conducted with rats, researchers say that kids who drink alcohol may have trouble with decision-making in adulthood.

Alcohol consumption during adolescence can change the perception of risk but does not affect how rewards are valued, the University of Washington researchers found.

The investigators studied decision-making in adult rats that had been given free access to alcohol when they were adolescents. The researchers measured changes in the neurotransmitter dopamine when the rats were offered rewards alone and also in response to cues predicting risky or certain outcomes.

"Dopamine is central to the way we process and evaluate rewards and is the primary target in the brain for virtually all abused drugs," study author Jeremy J. Clark, an acting assistant professor of psychiatry and behavioral sciences, explained in a university news release.

In the rats, alcohol use during adolescence increased dopamine signaling to risky options but did not affect responses to rewards.

"Alcohol is corrupting the ability to make a good decision by altering the perception of risk. It doesn't appear to be about the reward," Clark said.

The study was published March 14 in the journal Proceedings of the National Academy of Sciences.

The study authors noted that the findings might lead to improved treatments for those with a history of substance abuse.

More information

The U.S. National Institute on Alcohol Abuse and Alcoholism has more about underage drinking.

New Treatment for Thrombosis?

ScienceDaily

Thursday, March 17, 2011

ScienceDaily (Mar. 17, 2011) — Scientists from the University of Reading have announced a breakthrough in understanding how to control blood clotting which could lead to the development of new treatments and save the lives of thousands of people each year.

Doctors have known for some time that high levels of blood cholesterol can increase the risk of suffering from a heart attack or a stroke. Controlling cholesterol levels has therefore become an important way to reduce the risk of these serious diseases. This has led to the development of drugs that control the function of a protein within our bodies called LXR which regulates cholesterol.

However, researchers from the School of Biological Sciences have discovered that this protein has a double life.

The protein also appears to be involved in inhibiting the function of blood cells known as platelets, a role that is unconnected to cholesterol levels but which results in reducing the blood clotting response. In the research blood clot formation was inhibited by 40%.

Drugs that target LXR may therefore have benefit in reducing cardiovascular disease for two separate reasons: preventing thrombosis, and controlling cholesterol levels.

Professor Jon Gibbins, Director of the University's Institute for Cardiovascular and Metabolic Research, said: "While blood clotting is essential to prevent bleeding, inappropriate clotting within the circulation, known as thrombosis, is the trigger for heart attacks and strokes -- which kill more people in the UK each year than any other disease."

The study was funded by the British Heart Foundation and Heart Research UK. Researchers found that targeting the LXR protein with anti-thrombotic drugs in mice reduced the size and stability of blood clots (thrombi). The treatment allowed initial thrombi to form (a physiological process necessary to prevent bleeding after injury to blood vessels) but reduced by approximately 40% the stability of the thrombi, preventing clots blocking blood vessels.

Professor Jeremy Pearson, Associate Medical Director at the British Heart Foundation, said: "Both anti-clotting and cholesterol-lowering drugs are vital in reducing the chance of a heart attack or stroke in high-risk patients, but are not always effective and don't suit all patients because of the risk of side-effects.

"This exciting discovery by Professor Gibbins' team shows that drugs which lower cholesterol through targeting LXR protein can also reduce harmful blood clotting -- potentially opening up paths towards new, more effective treatments."

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:

M. Spyridon, L. A. Moraes, C. I. Jones, T. Sage, P. Sasikumar, G. Bucci, J. M. Gibbins. LXR as a novel anti-thrombotic target. Blood, 2011; DOI: 10.1182/blood-2010-09-306142 

Wednesday, March 16, 2011

Vitamin E users show lower ALS risk

Reuters Health

Wednesday, March 16, 2011

NEW YORK (Reuters Health) – People who regularly take vitamin E supplements over the years may have a decreased risk of developing the fatal neurological condition amyotrophic lateral sclerosis (ALS), a new study suggests.

ALS -- also known as Lou Gehrig's disease -- is an invariably fatal disease in which the nerve cells that control movement progressively degenerate, leading to paralysis and death from respiratory failure. It is diagnosed in about 5,000 Americans each year.

Up to 10 percent of ALS cases are an inherited form of the disease. In most cases, though, ALS occurs for no known reason.

Some research has suggested that people with higher intakes of vitamin E have a lower risk of ALS. Those findings do not prove that vitamin E is the reason, but lab research has found that the vitamin -- which acts as a cell-protecting antioxidant -- can delay the onset of symptoms in mice genetically altered to develop an ALS-like condition.

Since ALS is so rare, researchers need to study large groups of people to see what lifestyle factors might be related to the disease.

So for the new study, researchers at Harvard University combined the results of five large U.S. studies involving more than 1 million adults in all.

They found that there was a relationship between the length of vitamin E use and ALS.

People who, at the start of their study, had been using vitamin E supplements regularly for at least five years were about one-third less likely than non-users to develop ALS.

However, it's too soon to make any recommendations on vitamin E, Dr. Eilis J. O'Reilly and her Harvard colleagues report in the American Journal of Epidemiology.

For one, the findings do not prove that vitamin E, itself, provided the benefit. The researchers did try to account for other lifestyle factors -- like people's weight, smoking habits, overall diet and exercise levels. And longer use of vitamin E supplements (from multivitamins or single supplements) was still linked to a lower ALS risk.

But there could still be other explanations for the finding. And promising findings on vitamin E have failed to pan out in the past.

Researchers once thought vitamin E supplements might prevent heart disease, based on studies showing lower rates among vitamin E users. But clinical trials -- where people were randomly assigned to take vitamin E or a placebo -- later showed no such benefit.

In addition, the current findings are based on small numbers. Of the 1 million-plus study participants, 805 were eventually diagnosed with ALS. And of those who had been using vitamin E for at least five years at the outset, just 18 developed ALS; there were 19 cases among people who had used the vitamin for fewer years.

Further studies, O'Reilly's team writes, are needed to see whether vitamin E does in fact affect ALS risk.

In general, experts recommend that adults get 15 milligrams, or 22 international units (IU), of vitamin E each day.

Food sources include wheat germ, nuts such as almonds and hazelnuts, vegetable oils such as sunflower and safflower oils, and some green vegetables, such as spinach and broccoli.

It's unlikely that people could get too much vitamin E from food. But high doses of vitamin E from supplements carry a risk of bleeding. Experts advise that adults consume no more than 2,500 IU of synthetic vitamin E per day.

Multivitamins usually contain 30 IU of vitamin E, while the typical dose in single supplements is 400 IU.

Source: http://bit.ly/hqRiq3

American Journal of Epidemiology, online February 18, 2011.

High Blood Pressure Linked to Drop in Walking Speed, Study Finds

HealthDay News

Wednesday, March 16, 2011

Wednesday, March 16 (HealthDay News) -- High blood pressure is associated with a steeper drop in the average walking speeds of seniors, a new study finds.

Major decreases in walking speed can affect a senior's ability to remain independent and indicate possible health problems; it may also predict who will develop dementia or disabilities, the researchers said.

They tracked the walking speeds of 643 seniors over 14 years. The participants, who were 76 at the start of the study, included 350 without high blood pressure and 293 who had undiagnosed hypertension or were taking medication for the condition.

The participants were divided into three groups: those without hypertension, those whose hypertension was diagnosed and under control; and those who were diagnosed and whose hypertension was not under control.

At the start of the study, the participants' average walking speed was 2.2 mph. During the follow-up, the walking speed of those in the two high blood pressure groups decreased 0.2 miles per hour more than those without high blood pressure -- a 10 percent decline.

The decline in walking speed seemed to occur even among those whose high blood pressure was successfully treated, said Dr. Caterina Rosano, of the University of Pittsburgh, and colleagues.

Further research is needed to learn more about the link between high blood pressure and the sharp drop in walking speeds, she added.

The study, published in the March issue of the Journal of the American Geriatric Society, received funding from the U.S. National Heart, Lung, and Blood Institute, part of the National Institutes of Health.

"The findings from this study suggest an additional reason to stress prevention of high blood pressure," NHLBI Acting Director Dr. Susan B. Shurin said in an institute news release. "Even with medications to treat high blood pressure in older adults, it appears that the condition might be linked to a serious decline in average walking speed. As the mobility of seniors declines, there is an increased risk for falls."

More information

The AGS Foundation for Health in Aging has more about walking problems.

Inflammation Behind Heart Valve Disease, Research Suggests

ScienceDaily

Wednesday, March 16, 2011

ScienceDaily (Mar. 16, 2011) — Research from Karolinska Institutet in Sweden shows that a specific inflammatory factor may be important in the development of the heart valve disease aortic stenosis. The results suggest that anti-inflammatory medication could be a possible new treatment.

Aortic stenosis is the most common heart valve disease, which is caused by calcium deposits and a narrowing of the aortic valve. This is typically seen in the elderly, but can also be caused by a congenital defect. Aortic stenosis is currently treated by surgical replacement of the diseased valve, but research is on-going for identifying medicines which can delay the progress of the disease.

In a new study presented in the journal Circulation, researchers from Karolinska Institutet show that specific pathways of inflammation are important underlying factors in the development of aortic stenosis.

By studying heart valves from patients undergoing surgery for various valve diseases, the researchers have shown that immune cells and a group of inflammatory substances called leukotrienes can be found in calcified heart valves. The most significant inflammation was seen in patients with the narrowest valves on ultrasound examination. The researchers have also shown in cell cultures that leukotrienes stimulate the calcification of heart valve cells.

There are similarities between atherosclerosis (calcification of the arteries) and aortic stenosis. However, lipid-lowering medicines known as statins which are capable of preventing atherosclerosis have proved ineffective in preventing calcification of the aortic valve.

"The results suggest that anti-inflammatory medication could be a future treatment for aortic stenosis, and it would mean a lot to these patients, most of whom are elderly, if we could slow the disease to the extent that they do not need surgery," says associate professor and cardiologist Magnus Bδck, one of the researchers behind the study.

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:

Edit Nagy, Daniel C. Andersson, Kenneth Caidahl, Maria J. Eriksson, Per Eriksson, Anders Franco-Cereceda, Gφran K. Hansson, Magnus Bδck. Upregulation of the 5-Lipoxygenase Pathway in Human Aortic Valves Correlates With Severity of Stenosis and Leads to Leukotriene-Induced Effects on Valvular Myofibroblasts. Circulation, 2011; DOI: 10.1161/CIRCULATIONAHA.110.966846

Are high-protein diets bad for your colon?

By Amy Norton

Reuters Health

Wednesday, March 16, 2011

NEW YORK (Reuters Health) – The high-protein, low-carbohydrate diets many people turn to for weight loss might have potentially harmful long-term effects on the colon, a small study hints.

In a study of 17 obese men, UK researchers found that a protein-heavy, low-carb diet created certain changes in the colon that could, over time, contribute to colon cancer risk.

The study looked only at short-term shifts in certain compounds that are byproducts of metabolism, and not actual disease risk. So it does not show whether high-protein diets really raise the risk of any colon diseases.

But the findings raise that possibility, the researchers report in the American Journal of Clinical Nutrition.

"The concern raised by our studies is that the risk of colorectal cancer might be raised by long-term adherence to diets that are high in protein and low in carbohydrate, especially fiber," senior researcher Dr. Harry J. Flint, of the University of Aberdeen, told Reuters Health in an email.

So what does that mean for people who want to lose weight?

Diets relatively high in protein and lower in carbs have been shown to help heavy people shed pounds. And, Flint and his colleagues point out, obesity is thought to be a risk factor for a number of diseases, including colon cancer.

"People should not be discouraged from losing weight, as this offers important health benefits," Flint said.

However, he added, they should make sure that any weight loss plan they follow includes adequate amounts of fiber. People should also be aware, Flint said, that a high protein intake over months to years might have ill effects in the colon.

The findings are based on 17 obese men who each followed three short-term diets: a one-week menu plan designed to maintain their weight; a four-week high-protein diet with moderate amounts of carbohydrates; and a four-week high-protein diet low in carbs.

The first diet, which allowed about 360 grams of carbs per day, typically offered cereal, eggs and toast for breakfast; a sandwich and salad for lunch; and chicken, fish or soy, along with pasta, for dinner.

The low-carb diet -- which allowed just 22 grams of carbs each day -- generally consisted of eggs-and-bacon breakfasts, and lunches and dinners heavy in meat, poultry and fish, along with some vegetables and cheese.

The moderate-carbohydrate diet allowed 181 grams of carbs each day. Both high-protein diets contained just less than 140 grams of protein per day.

At the end of each diet period, Flint's team analyzed fecal samples from the men to look at levels of certain metabolic byproducts.

On average, the study found, when the men were on the high-protein diets, they had higher levels of substances known as N-nitroso compounds, and certain other metabolites that have been linked to cancer.

And when they were on the high-protein, low-carb diet, they had lowered concentrations of fiber-derived compounds thought to be protective against cancer.

Exactly what those changes might mean for a person's long-term health is not clear. But Flint said that the findings suggest that people should be cautious about consuming too much protein and too little fiber over a prolonged period.

People seeking to lose weight, he and his colleagues say, should be sure to get enough fiber in their diets. In general, experts recommend that adults get about 28 grams of fiber per day -- though it's not known whether that's enough for someone on a high-protein weight-loss diet.

Flint and his colleagues are currently studying that question.

Source: http://bit.ly/eaIyu4

American Journal of Clinical Nutrition, online March 9, 2011.

Tuesday, March 15, 2011 

ADHD and Prenatal Alcohol Exposure: Comparing Profiles of Learning and Memory Impairments in Two Groups of Children

ScienceDaily

Tuesday, March 15, 2011

ScienceDaily (Mar. 15, 2011) — While children with fetal alcohol spectrum disorders (FASD) are known to have deficits in verbal learning and recall, the specifics of these deficits remain unclear. This study compared the verbal learning and memory performance of children with heavy prenatal alcohol exposure (PAE) with that of children with attention-deficit/ hyperactivity disorder (ADHD), finding that both groups of children have difficulty with learning and memory but in different ways.

Results will be published in the June 2011 issue of Alcoholism: Clinical & Experimental Research and are currently available at Early View.

"Children with FASD and ADHD can appear very similar," explained Sarah N. Mattson, a professor in the department of psychology at San Diego State University and corresponding author for the study. "Both alcohol-exposed children and those with ADHD demonstrate behavioral difficulties such as hyperactivity and impulsivity, and children with FASD often meet diagnostic criteria for ADHD. Studies that compare these groups can aid in accurate identification and appropriate diagnoses, which are important as they have implications for the kinds of interventions and resources provided to these children and their families."

"The broad range of neurodevelopmental, cognitive, and behavioral abnormalities that occur in FASD most likely result from a combination of prenatal alcohol exposure and other factors such as other drug exposures, disrupted home environment, abuse, and co-morbid conditions," added Jeffrey R. Wozniak, assistant professor of psychiatry at the University of Minnesota. "This heterogeneity or wide range of potential problems among this population remains a significant challenge to researchers attempting to identify a 'profile' of abnormalities that are associated with PAE."

Mattson and her colleagues used the California Verbal Learning Test -- Children's Version (CVLT-C) to examine three groups (n=22/group) of children, ages seven to 14: those with heavy PAE and ADHD (10 boys, 12 girls); those not exposed to alcohol and with ADHD (14 boys, 8 girls); and those not exposed to alcohol and without ADHD (12 boys, 10 girls). The groups were matched on age, sex, race, ethnicity, right or left-handedness, and socioeconomic status. The test required the children to learn and remember a list of words.

"The children with alcohol exposure had problems with learning information initially, but they were able to remember what they did learn later on," said Mattson. "The children with ADHD, however, were better at recalling information immediately after it had been presented but had difficulty retaining this information over time."

"This pattern of results suggests that FASD may be associated with a specific deficit in the initial encoding of verbal information while, in contrast, ADHD may be associated with a deficit in retrieval," said Wozniak. "The authors speculate that the encoding problems seen in FASD may be related to underlying difficulties in executive functioning -- those processes by which a child organizes and directs his/her own learning."

Mattson explained that "inefficient encoding of verbal material" means that when children are presented with verbal information, they have difficulty learning that information. "If children have encoding deficits, it may be experienced as a memory problem as they will recall less than their peers," she said. "They may also find it difficult to remember and follow instructions given to them by teachers or parents and have difficulty learning material presented in the classroom."

A "deficit in retrieval of learned material," on the other hand, is related to memory but is different from "forgetting," said Mattson.

"If a child has a difficulty retrieving learned material, the problem is related to accessing material that is stored in the brain," Mattson explained. "These children won't be able to independently generate the material, but if you presented them with some choices they could recognize the correct answer. 'Forgetting' refers to learned information that is no longer available for recall."

"Children with FASD might need additional repetition of the information as well as guidance about how to organize the information as they are learning it," added Wozniak. "In contrast, children with ADHD might benefit most from assistance in developing strategies for retrieving information from memory, such as self-cueing."

"This research has important implications for clinicians and educators," noted Mattson. "Understanding the profiles of learning and memory impairments in these populations of children can allow for appropriate intervention and remediation strategies to be implemented."

Wozniak agreed. "Both educators and clinicians will benefit from knowing that children with FASD are, in fact, struggling at the level of encoding information but that their retrieval mechanisms are less affected. Individuals with FASD might benefit most from additional efforts to improve their initial encoding, such as developing strategies for active learning and techniques for 'deepening' their initial processing in order to improve encoding of the information into memory."

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:

Nicole Crocker, Linnea Vaurio, Edward P. Riley, Sarah N. Mattson. Comparison of Verbal Learning and Memory in Children With Heavy Prenatal Alcohol Exposure or Attention-Deficit/Hyperactivity Disorder. Alcoholism: Clinical and Experimental Research, 2011; DOI: 10.1111/j.1530-0277.2011.01444.x 

Monday, March 14, 2011

Diets Rich in Vitamin B May Help Prevent PMS, Study Finds

HealthDay News

Monday, March 14, 2011

MONDAY, March 14 (HealthDay News) -- Women may be less likely to develop premenstrual syndrome if they eat a diet rich in two types of B vitamins, a new study suggests.

Women who consumed thiamine (B1) and riboflavin (B2) in their food significantly reduced their risk of PMS, the data suggested. Thiamine is found in fortified cereals, whole grains, beans and nuts, and researchers said eating two to three servings of thiamine-rich foods a day appeared to thwart PMS.

Riboflavin is available in milk, eggs, meat and green vegetables. Eating one to two servings of fortified cereal or six to seven servings of foods such as spinach, cow or soy milk, or red meat seemed to have a beneficial effect, the researchers found.

The study, led by Dr. Patricia O. Chocano-Bedoya of the University of Massachusetts, Amherst, followed more than 3,000 women participating in the U.S. Nurses Health Study II. All of the women were free of PMS at the start of the study, and they filled out dietary questionnaires three times between 1991 and 1999.

"We observed a significantly lower risk of PMS in women with high intakes of thiamine and riboflavin from food sources only," the authors concluded.

Specifically, women with the highest riboflavin intake had a 35 percent lower risk of developing the physical and emotional symptoms of PMS symptoms compared with those who consumed the least, the researchers found.

According to background information in the study, thiamine and riboflavin may have an impact on brain neurotransmitters such as serotonin and dopamine, which have been linked to PMS.

However, the study, published recently online in the American Journal of Clinical Nutrition, doesn't actually prove that these vitamins will prevent PMS. Other factors could play a role as well, the researchers said.

PMS is a cluster of symptoms that can range from mild to severe. A woman with PMS may experience physical or emotional changes several days before the start of her period. These may include swollen, tender breasts; acne; joint pain; memory problems; anxiety and/or depression, and for some women these changes affect their quality of life.

Intake of vitamin-B supplements did not appear to influence development of PMS. Nor did consumption of niacin, vitamin B-6, folate, and vitamin B-12 in foods, the researchers said.

The authors said additional research should further explore the link between these two B vitamins and the development or treatment of PMS.

More information

The American Congress of Obstetricians and Gynecologists has more about PMS.

Omega-3s linked to less age-related vision loss

By Frederik Joelving

Reuters Health

Monday, March 14, 2011

NEW YORK (Reuters Health) – Women who get lots of omega-3 fatty acids are less likely to develop age-related macular degeneration (AMD), an eye disease affecting millions of older adults in the U.S.

That's the conclusion of a new study, which jibes with earlier research linking fish consumption to slower progression of AMD. Fish rich in omega-3 fatty acids such as DHA and EPA include salmon, trout, sardines, herring and tuna.

AMD is caused by abnormal blood vessel growth behind the retina or breakdown of light-sensitive cells within the retina itself -- both of which can cause serious vision impairment. Some 1.7 million Americans have severe vision loss due to the disease, making it the leading cause of blindness in older adults.

At this point, doctors can halt AMD, but they can't reverse damage to the retina. So researchers have been busy looking for ways to stave off the disease.

"Other than giving up cigarette smoking or never starting smoking, there are no known ways to prevent AMD," said William G. Christen of the Brigham and Women's Hospital in Boston, who worked on the new study, published in the Archives of Ophthalmology.

Christen and colleagues used data from earlier research called the Women's Health Study, in which women 45 years and up had filled out extensive diet questionnaires.

After 10 years, 235 out of 38,022 women had developed AMD severe enough to damage their vision.

When the researchers looked at all food sources of the important fatty acids, the risk of AMD was 38 percent lower in women with the top one-third DHA intake compared to those with the bottom one-third intake. For those who got a lot of EPA, the risk was 34 percent smaller.

"We also looked at the food intake of (just) fish and the data were consistent there," said Christen, also of the Harvard Medical School.

He pointed out, however, that it is too early to recommend that people start supplementing their diet with fish or with fish oil supplements to stave off eye disease.

That's because the study was based on observations, not on a real experiment, and so it can't rule out that women who got lots of omega-3s were simply healthier people.

"It supports the need for randomized clinical trials," said Christen. "The best advice we have at this point is, don't smoke."

Source: http://bit.ly/hd0ewW

 

Archives of Ophthalmology, online March 14, 2011.

In Men, Duration of Diabetes Linked to Raised Heart Risk

By Amanda Gardner
HealthDay Reporter
HealthDay News

Monday, March 14, 2011

MONDAY, March 14 (HealthDay News) -- When a man develops type 2 diabetes could determine his risk of a heart attack, a new study finds.

In fact, men who have had type 2 diabetes for a decade or more face the same risk as those who have already had a prior heart attack, the researchers found.

The findings, appearing this week in the March 14 issue of Archives of Internal Medicine, may help to stratify patients based on risk level, to better determine who needs what type of care and when.

"You don't want to give all these big, powerful, expensive medicines to every single person. Maybe we can tease out the group that would benefit more," said Dr. Robert Scott III, an associate professor of internal medicine at Texas A&M Health Science Center College of Medicine and senior staff cardiologist at Scott & White in Temple, Texas. He was not involved in the new study.

Prior research had indicated that the risk of heart disease in people with type 2 diabetes was the same as in people who had had a previous heart attack. But this research indicates that the risk really does have more to do with timing.

After following about 4,000 men aged 60 to 79 for nine years, British researchers led by S. Goya Wannamethee of University College London, found a higher risk of heart attacks and death in all those who had diabetes, compared to men who didn't have the illness.

Risk rose along with duration of disease -- compared to men without diabetes, men who had early-onset diabetes (in this case, for an average of 17 years or more) had 2.5 times the risk of a heart attack. That level of risk was equal to that of men with a prior history of heart attack, the team noted.

Men who had late-onset diabetes (an average of five years with the disease) had a 54 percent increased risk of a heart attack or of dying.

The risk for cardiovascular problems rose significantly after a man had had diabetes for eight years, the team found.

None of these risk differences were affected by more typical risk factors for heart attack, such as inflammation of the arteries.

"The bottom line was that men who had had diabetes longer, in other words early-onset diabetes diagnosed [in this study] before age 60, had more heart attacks and more events," Scott said. "And therefore they truly did look equivalent to patients who had had a prior heart attack and no diabetes. It looks like it really was an equivalent," he added.

"If a male aged 60 walks into my office who just got diagnosed yesterday and didn't have any known heart disease, I might not be as aggressive [in treating him] as we are today," he noted. "That way the patient has less side effects to the medicine and less cost."

But another expert said that clinical implications from the new study remain unclear.

Dr. Chad Teeters, assistant professor of clinical medicine at the University of Rochester Medical Center, said that one problem with the study was that the patients were all older, many had heart risk factors known as "metabolic syndrome," and many were physically inactive, all of which are risk factors for heart disease.

Given this limitation, he said, the new research "doesn't change the game" of how patients are treated.

The study didn't look at men under the age of 60, but the authors did note that people are now getting diagnosed with type 2 diabetes at earlier and earlier ages, perhaps indicating more people who are in need of more aggressive treatment.

And what about the heart risks posed to women by diabetes?

According to Teeters, "Cardiac risk in women doesn't begin to accumulate until later in life due to the protective effects of estrogen, so the effect of duration of diabetes may or may not be similarly associated with cardiac risk in women as it is in men."

Another expert agreed.

"Studies have shown that diabetes is more of a risk factor for heart attacks in men, [but] we don't know anything about [women's risk] from this study," noted Dr. Suzanne Steinbaum, a preventive cardiologist with Lenox Hill Hospital in New York City. "I don't think this gives us any information on women."

More information

There's more on connections between heart disease and diabetes at the American Heart Association.

Study: Lack of Vitamin D May Precede Onset of Parkinson's

HealthDay News

Monday, March 14, 2011

MONDAY, March 14 (HealthDay News) -- A lack of vitamin D is common among people with early Parkinson's disease, but levels of the vitamin don't decrease as the disease progresses, a new study says.

"Vitamin D insufficiency has been associated with a variety of clinical disorders and chronic diseases, including impaired balance, decreased muscle strength, mood and cognitive dysfunction, autoimmune disorders such as multiple sclerosis and diabetes (types 1 and 2), and certain forms of cancer," the study authors wrote as background information for their research. "Vitamin D insufficiency has been reported to be more common in patients with Parkinson disease (PD) than in healthy control subjects, but it is not clear whether having a chronic disease causing reduced mobility contributes to this relatively high prevalence."

The researchers looked at 157 people with early, untreated Parkinson's disease and found that 69.4 percent had some lack of vitamin D, and 26.1 percent had vitamin D deficiency at the start of the study.

"At the end point/final visit, these percentages fell to 51.6 percent and 7 percent, respectively," wrote Dr. Marian L. Evatt, of Emory University School of Medicine and the Atlanta Veterans Affairs Medical Center, and colleagues.

The study was published in the March issue of the journal Archives of Neurology.

"Contrary to our expectations that vitamin D levels might decrease over time because of disease-related inactivity and reduced sun exposure, vitamin D levels increased over the study period," the researchers wrote.

"These findings are consistent with the possibility that long-term insufficiency is present before the clinical manifestations of PD and may play a role in the pathogenesis of PD," they added.

More information

We Move has more about Parkinson's disease.

Mental Decline May Start Years Before Alzheimer's

By Steven Reinberg
HealthDay Reporter

HealthDay News

Monday, March 14, 2011

MONDAY, March 14 (HealthDay News) -- When Alzheimer's disease actually starts is often not clear, but it now appears that it may be preceded by rapid cognitive decline for up to six years before it becomes evident, a new study suggests.

This accelerated deterioration in memory and other mental function is not seen in people who do not develop Alzheimer's disease, the researchers said.

"Alzheimer's disease has a much longer course and affects substantially more people than generally recognized," said lead researcher Robert S. Wilson, a senior neuropsychologist at the Rush Alzheimer's Disease Center in Chicago.

"The results provide further evidence of the magnitude of the public health problem posed by Alzheimer's disease and related disorders and underscore the importance of developing strategies to delay its onset," he said.

For the study, published in the March issue of Archives of Neurology, Wilson's team evaluated information on 2,071 older adults without dementia who took part in two separate studies, including 1,511 who had no signs of cognitive impairment.

The participants were tested on specific cognitive functions such as working memory, perceptual speed and visuo-spatial ability.

During 16 years of follow-up, 462 people developed Alzheimer's disease.

"We found that dementia in Alzheimer's disease is preceded by an average of five to six years of rapid cognitive decline," Wilson said. In fact, the rate of cognitive decline in these participants accelerated more than 15-fold, the researchers noted.

"We also found that the precursor of Alzheimer's disease, mild cognitive impairment, is preceded by about six years of increased cognitive decline," he said. "By contrast, little cognitive decline was evident in people who did not develop these conditions."

Greg M. Cole, associate director for research at the Geriatric Research Clinical Center at the Greater Los Angles Veterans Medical Center and a professor at the University of California Los Angeles, said that the study "is important because researchers will have to test emerging prevention strategies in people with this type of accelerating early decline."

How well a treatment slows an early rate of decline may be useful in predicting prevention methods that work, he said.

"If we ever get there, it would be a great thing because the cost of prevention trials depends on the number of subjects and the time in the trial," he said. And, because most people who take part in trials do not develop Alzheimer's disease, there is a lot of wasted time and money, Cole said. Clinical trials can cost $40 million or more, even ones that fail, he noted.

Being able to predict which people were more likely to develop Alzheimer's would allow more bang for the buck. "If you cut that cost to, say, $5 million, you could do eight trials for the same cost and have eight times the probability of success," Cole said.

"With 450,000 new Alzheimer's disease cases every year and growing, something like this has to be done to try to find something that works and optimize it," he said.

More information

The Alzheimer's Association has more on Alzheimer's disease.

Breast cancer may not change lifespan for older women

By Genevra Pittman

Reuters Health

Monday, March 14, 2011

NEW YORK (Reuters Health) – Older women who are diagnosed with early-stage breast cancer can expect to live just as long as peers without breast cancer, according to a new study.

That's "a very encouraging message," said Dr. Elena Elkin, a breast cancer researcher at Memorial Sloan-Kettering Cancer Center who was not involved with the study. "More of the breast cancers we find are very small and diagnosed at an early stage. For older women especially these cancers generally have a favorable diagnosis," she told Reuters Health.

More than 200,000 women are diagnosed with breast cancer each year in the U.S., and a woman's risk of getting the disease increases as she gets older.

There is ongoing debate in the medical community, however, over whether routine screening for certain cancers will actually extend lives, particularly in older people whose life expectancy is likely to be influenced by other health issues, such as heart disease.

In the current study, researchers compared the life expectancy and causes of death in women age 67 and older who were diagnosed with breast cancer and in a similar group of women without breast cancer.

By consulting a register of cancer diagnoses in Medicare patients, the authors, led by Dr. Mara Schonberg of the Beth Israel Deaconess Medical Center in Brookline, Massachusetts, were able to identify almost 65,000 older women who were diagnosed with breast cancer of any stage between 1992 and 2003. For comparison, they collected information for a group of about 170,000 women of similar age, also on Medicare, who were not diagnosed with breast cancer.

The researchers tracked women in both groups through 2006 - close to 8 years of follow-up on average - to determine how many of them died, and from what cause.

Women diagnosed with ductal carcinoma in situ (DCIS) - the earliest stage of breast cancer - and stage I cancer were just as likely to survive through the end of the study period as women who were never diagnosed with cancer.

Women under 80 who were diagnosed with DCIS were actually slightly more likely to survive for at least 5 years than women who were not diagnosed with breast cancer. That could be because of the "healthy user effect," the authors say - women who are diagnosed with breast cancer are more likely to have been screened for cancer than women who aren't diagnosed, and may also be more health-conscious in other ways.

Women with stage I breast cancer and those over 80 with DCIS had the same rate of survival over the course of the study as women without breast cancer.

In women under 80 years old, 89 percent survived 5 years after a diagnosis of DCIS and 87 percent after being diagnosed with stage I cancer. In women age 80 and older, 70 percent were still alive 5 years after being diagnosed with DCIS, compared to 66 percent who were diagnosed with stage I breast cancer.

Between 6 and 18 percent of women with early stage cancer that died within 5 years died from breast cancer. Heart disease was the most common cause of death for women with early stage breast cancer.

Survival chances were higher in women with early-stage breast cancer when they had a mastectomy or breast-conserving surgery and radiation together, rather than when they just had breast-conserving surgery or had no surgery at all.

When older women were diagnosed with stage II or higher breast cancer, they did not survive as long as the non-cancer group. A stage II diagnosis, for example, meant women were 1.5 times less likely to survive the study period than women without breast cancer, and a stage III diagnosis meant they were three times less likely to survive.

The findings, the authors say, suggest that doctors should be talking with older women about the risks and benefits of being screened for breast cancer. Screening might pick up an early stage cancer that is advancing - in which case treatment could prevent the cancer from becoming worse.

In some cases, however, screening might pick up cancers that would not end up cutting a woman's life short, especially if she was at risk of dying from another condition, such as heart disease. In that sense, a woman is at risk of being treated with invasive procedures unnecessarily since they would not extend her expected lifespan.

"I suspect that a lot of these cancers are cancers that never would have affected someone's life expectancy" had they not been caught, Schonberg told Reuters Health. However, she said, it's very hard to know which cancers are going to progress and which are not likely to cause a woman's death.

"This is the fundamental problem in screening for cancer in general," Elkin added. She said that each woman's decision about whether or not to get screened should depend on how much she would benefit from doctors catching an early-stage cancer. Every older woman "should not just get a mammogram routinely, but have a discussion with her doctor," she said.

The main message is that "screening can be effective even in older women," Elkin said. "What's important is not necessarily a woman's age but her general health and her life expectancy ... and that's true for any age."

Source: http://bit.ly/eKY591

Journal of Clinical Oncology, online March 14, 2011.

Eating Fish Might Protect Your Eyesight

By Alan Mozes
HealthDay Reporter

HealthDay News

Monday, March 14, 2011

MONDAY, March 14 (HealthDay News) -- Women who consume fish regularly -- and the abundance of omega-3 fatty acids found in that meal choice -- have a lower risk of developing age-related macular degeneration (AMD), new research suggests.

This latest evidence of a protective link between fish oil and eye health mirrors past research that has found the same benefit. In this study, Harvard researchers performed a dietary analysis on more than 38,000 women.

"Our observational data needs to be confirmed in randomized trials," cautioned study author William G. Christen, an associate professor with the division of preventive medicine in the department of medicine at Brigham and Women's Hospital and Harvard Medical School in Boston.

"But already the message seems to be simple and strong," Christen added. "Fish oil, that is the omega-3 fatty acids found in fish, that have long been thought to be protective against cardiovascular disease may also be of significant benefit in the primary prevention of AMD among women who have no disease or have undetected early signs of disease, and have not yet been diagnosed with AMD."

Christen and his colleagues report on their research, which was funded partly by the U.S. National Institutes of Health, in the March 14 online edition of the Archives of Ophthalmology. The study will also appear in the June print issue of the journal.

The authors noted that about 9 million U.S. adults over the age of 40 have experienced some degree of AMD. Most have an early-stage form of the disease, while about 1.7 million have the advanced stage of illness that results in a serious loss of vision.

To date, there is no recognized method, aside from advising patients not to smoke cigarettes, to prevent or slow the onset of AMD among those who do not have the disease or only display the symptoms of early illness.

To explore how diet might function as a prevention tool, the investigators examined tens of thousands of food questionnaires completed by female health professionals who were enrolled in a heart disease and cancer prevention trial called the Women's Health Study.

No men were included in the study. All of the participants were in their 40s at the time of enrollment in 1993, and none had AMD at the study's start.

Eye health was also tracked over the course of a decade, during which time 235 women developed AMD.

The team observed that older women were more likely to consume higher amounts of both omega-3 fatty acids (which include docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), as well as omega-6 fatty acids (which include arachidonic acid and linoleic acid).

Those who consumed the greatest amount of one or both omega-3 fatty acids (DHA, EPA) were found to have a 38 percent lower risk of developing AMD compared with those women who consumed the least.

Specifically, women who ate one or more servings of fish every week had a 42 percent lower risk of AMD than those who consumed fish just once a month or less, the study found.

Most of the lower risk was linked to fish diets composed mainly of canned tuna and dark-meat fish, the researchers noted.

Although the authors uncovered a suggestion that higher consumption of one of the omega-6 fatty acids (linoleic acid) might actually boost the risk for AMD, that link was not deemed significant.

Christen and his associates concluded that their findings are "the strongest evidence to date" that omega-3 fatty acids protect against the onset of AMD.

Dr. David M. Kleinman, an associate professor and retina specialist with the Flaum Eye Institute at the University of Rochester in Rochester, N.Y., described the findings as "unsurprising, but very helpful."

"All scientists are going to say they need more research," he noted. "But this is great data, and it's supportive enough for me to already say to my patients, 'Eat fish. Or almonds.' Because realistically, we're talking about an intervention that has very little risk, and is something that we believe is really good for the eye."

More information

For more on age-related macular degeneration, visit the U.S. National Eye Institute.

Key Mutations Act Cooperatively to Fuel Aggressive Brain Tumor

ScienceDaily

Monday, March 14, 2011

ScienceDaily (Mar. 14, 2011) — St. Jude Children's Research Hospital investigators use a novel model system to show how specific mutations can induce glioma formation in multiple regions of the brain and to begin studying patient response to a new generation of targeted therapies.

Mutations in three pathways important for suppressing tumors cooperate to launch glioblastoma, an aggressive brain tumor that strikes children and adults. But new research from St. Jude Children's Research Hospital scientists shows those changes alone are not sufficient to cause cancer. Tumor formation requires additional mutations, some affecting different points in the same disrupted regulatory pathways.

Researchers demonstrated that in mouse models of glioblastoma, tumors develop in several regions of the brain.

The findings, as well as the technique investigators used to generate them, are now being used as a possible tool for understanding patients' responses to investigational therapies that target some of the same pathways. The research appears in the March 15 edition of the scientific journal Cancer Cell.

The work builds on previous studies that linked glioblastoma to disruptions in the RB1, p53 and Pten pathways, each of which has a key role in preventing tumor formation. For this study, St. Jude investigators developed a novel system that allowed them to delete the genes, either singly or in various combinations, for which the pathways are named. Researchers then tracked the impact of those deletions on the brains of adult mice.

Gliomas are the most common primary malignant brain tumor, representing more than half of the 18,000 malignant brain tumors diagnosed annually in the U.S. These tumors remain the second most common cause of cancer death among individuals ages 15 through 44. Survival is less than 10 percent for patients with the most aggressive gliomas subtype, glioblastoma.

"In this study, we set out to look at the contribution of each of these pathways and how they cooperate to generate gliomas," said Suzanne Baker, Ph.D., a member of the St. Jude Department of Developmental Neurobiology and the paper's senior author. "When you analyze a human tumor, you see all of the accumulated mutations and you don't really know in what order they happened. This experimental system provides an opportunity to initiate a tumor with specific mutations and then ask: What else gives the tumor a selective advantage?"

Investigators found that when Pten, Tp53 and RB1 were all silenced, mice quickly developed high-grade gliomas. In contrast, losing just one of the genes failed to generate the tumors at a high frequency.

In this experimental model, loss of Tp53 was essential for tumor formation, suggesting the gene plays an important role in launching the disease. "But other mutations are still necessary," Baker said.

An analysis of DNA deletions and duplications in the tumors that developed in mice suggests the initiating mutation strongly influences which additional mutations provide a selective advantage to the rogue cell. For example, researchers found genes in the PI3 kinase pathway were commonly amplified in tumors sparked by Pten deletion, but were less common if Rb deletion was also introduced at the initiation of the experiment. Other genes in the Rb pathway were also amplified in tumors regardless of whether Rb deletion was one of the initiating mutations. These pathways regulate cell differentiation, proliferation and death.

The study also addresses the ongoing question of where gliomas begin. Previous work pointed to the brain niche where neural stem cells are found as the origin. Neural stem cells are the undifferentiated cells that give rise to the other, more specialized components of the nervous system. But in this study, 22 percent of the 63 gliomas developed in regions of the brain and spinal cord far from such niches. "That is consistent with what happens in humans and shows that the tumors can certainly develop in areas of the brain outside of the proliferative niches where stem cells are found," Baker said.

The cooperation and complexity identified in this study as driving tumor development have Baker and her colleagues asking new questions. Some focus on a family of drugs known as kinase inhibitors that target some of the same pathways this study showed work cooperatively to drive cancer. "Our mouse model gives us the opportunity to test some of the interesting new agents now being developed and decipher whether tumors that have multiple mutations in these pathways are more or less susceptible to such agents," Baker said. By understanding the pathways that tumor cells depend on, scientists hope to develop better tools for predicting patient response to these same drugs.

Lionel Chow, Cincinnati Children's Hospital Medical Center, formerly a postdoctoral fellow at St. Jude Children's Research Hospital, is the study's first author. The other authors are Raelene Endersby, formerly of St. Jude; Xiaoyan Zhu, Sherri Rankin, Chunxu Qu, Junyuan Zhang, Alberto Broniscer and David Ellison, all of St. Jude.

This work was supported in part by the National Institutes of Health, the Ryan McGee Foundation and ALSAC.

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:

Lionel M.L. Chow, Raelene Endersby, Xiaoyan Zhu, Sherri Rankin, Chunxu Qu, Junyuan Zhang, Alberto Broniscer, David W. Ellison, Suzanne J. Baker. Cooperativity within and among Pten, p53, and Rb Pathways Induces High-Grade Astrocytoma in Adult Brain. Cancer Cell, Volume 19, Issue 3, 305-316, 8 March 2011 DOI: 10.1016/j.ccr.2011.01.039

Stroke More Likely in People With Retinal Disease

HealthDay News

Monday, March 14, 2011

MONDAY, March 14 (HealthDay News) -- New research has linked an eye disease called retinal vein occlusion to an increased risk for stroke.

The disease, referred to as RVO, occurs when the small veins that carry blood away from the retina become blocked. Although more common in adults, RVO can occur at any age. Having diabetes, high blood pressure or vascular disease made development of RVO more likely.

For the study, researchers compared the rates of heart attack and stroke in 4,500 people with RVO and 13,500 without the condition. Those with RVO had an almost twofold higher incidence of stroke -- rates of 1.16 vs. 0.52 strokes per 100 person-years.

No statistically significant differences in heart attack rates between the two groups were detected.

The findings, published in the March issue of Archives of Ophthalmology, suggest that people with RVO and their doctors should be aware of the possible increased likelihood of a stroke, the researchers concluded.

More information

The U.S. National Library of Medicine has more about retinal vein occlusion.

Antioxidants in Pregnancy Prevent Obesity in Animal Offspring

ScienceDaily

Monday, March 14, 2011

ScienceDaily (Mar. 14, 2011) — New biological research may be relevant to the effects of a mother's high-fat diet during pregnancy on the development of obesity in her children.

An animal study at The Children's Hospital of Philadelphia suggests that a high-fat, high-carbohydrate diet causes oxidative stress (an excess of deleterious free radicals) during pregnancy, predisposing the offspring to obesity and diabetes. Feeding rats antioxidants before and during pregnancy completely prevented obesity and glucose intolerance in their offspring.

If the results in animals prove to be similar in humans, the research may have implications for reducing obesity rates in children. "We already know that there are critical periods during human development that influence the later development of obesity," said senior author Rebecca A. Simmons, M.D., a neonatologist at The Children's Hospital of Philadelphia. "This research suggests that if we can prevent inflammation and oxidative stress during pregnancy, we may lower the risk that a child will develop obesity."

The study by Simmons and co-author Sarbattama Sen, M.D., was published in the December 2010 print edition of Diabetes.

Oxidative stress is a condition in which quantities of highly reactive oxygen-containing molecules (free radicals and other chemicals) exceed the body's ability to control their biological damage to cells. It is already known that obesity in people contributes to oxidative stress, in part by causing inflammation. Furthermore, obesity during pregnancy creates an abnormal metabolic environment during human gestation.

The current study tested the hypothesis that a high-fat diet during pregnancy increases oxidative stress and leads to obesity in the offspring of animals. Simmons and Sen also investigated whether supplementing the animals' diet with antioxidants would prevent obesity in the offspring.

The researchers simulated a Western-style diet by feeding high-fat, high-carbohydrate chow to one group of rats, compared to a control group fed a more balanced diet. In two other groups (one fed a Western diet, the other fed a control diet), the researchers added antioxidant vitamins.

Among the rats that ate only the Western diet, the offspring had significantly higher measures of inflammation and oxidative stress, and as early as two weeks of age, were significantly fatter, with impaired glucose tolerance compared to control rats. However, rats eating the Western diet plus antioxidants had offspring with significantly lower oxidative stress, as well as no obesity and significantly better glucose tolerance. The effects persisted at two months of age.

"These results suggest that if we prevent obesity, inflammation and oxidative stress in pregnant animals, we can prevent obesity in the offspring," said Simmons. Simmons added that a next step in this research is to determine the mechanisms by which inflammation and oxidative stress cause more fat tissue to develop.

She cautioned that until these effects are carefully studied in people, one shouldn't conclude that the biological effects seen in animals are the same in humans. In the meantime, she added that, whether pregnant or not, women should certainly not conclude from this study that they should consume large doses of antioxidant vitamins.

The National Institutes of Health and the Diabetes and Endocrinology Research Center at the University of Pennsylvania supported this study.

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:

S. Sen, R. A. Simmons. Maternal Antioxidant Supplementation Prevents Adiposity in the Offspring of Western Diet-Fed Rats. Diabetes, 2010; 59 (12): 3058 DOI: 10.2337/db10-0301

Health Tip: Who's at Risk for Cardiomyopathy

HealthDay News

Monday, March 14, 2011

(HealthDay News) -- Cardiomyopathy is the umbrella term for various conditions that cause the heart muscle to become enlarged, thicken or stiff.

Not every person with cardiomyopathy has noticeable symptoms, the U.S. National Heart, Lung, and Blood Institute says, so it's important to learn the major risk factors. Here's the agency's list:

Having other family members with a history of cardiomyopathy, heart failure or sudden cardiac arrest.

Having another condition that can lead to cardiomyopathy, such as a prior heart attack, heart disease or heart inflammation due to a viral infection.

Being diabetic, having a metabolic disorder or being severely obese.

Having had a disease that causes heart damage.

Being a long-time alcoholic.

Having had high blood pressure for a long time.