WEDNESDAY, Aug. 5 (HealthDay News) -- A new review shows that the omega-3 fatty acids found in certain fish not only prevent cardiovascular disease, but may even help treat it.

"A lot of people know that omega-3 fatty acids are a good thing, but have thought of them in the area of nutritional or health foods," said study author Dr. Carl J. Lavie, medical director of cardiac rehabilitation and prevention at the Ochsner Clinic in New Orleans. "They don't realize there is so much data, a lot of data from big studies, that they are not only preventive but also help in therapy for a number of conditions, such as atrial fibrillation, heart attack, atherosclerosis and heart failure."

The report in the Aug. 11 issue of the Journal of the American College of Cardiology cites four trials with almost 40,000 participants that show benefits of omega-3 fatty acids in primary prevention of cardiovascular disease, in treatment after heart attack and, most recently, in heart failure patients.

The benefits of omega-3 fatty acids are such an old story that such studies can go unnoticed, Lavie said. "If you polled cardiologists about whether this is a good thing or a bad thing, I don't know if they would recognize how much has been done in this area," he noted.

As far back as 2002, the American Heart Association issued a scientific statement endorsing omega-3 fatty acid intake, from fish or supplements. It recommended specific amounts of omega-3 fatty acids each day for people in general, with greater intake recommended for people with heart disease.

"For the general population, it should be 500 milligrams a day," Lavie said. "If you have heart disease, it should be 800 or 1,000 milligrams a day."

Lavie includes himself in the second category, because "I have a family history of heart disease. I eat a lot of fish and take a supplement just to be sure."

It's got to be the right kind of fish, the oily species that have a lot of omega-3 fatty acids, Lavie added. "Redfish, trout, salmon," he said. "Salmon is my favorite."

Not much effort is needed for most people to achieve the recommended intake, Lavie said. "Five hundred milligrams a day is two fatty fish meals per week," he added.

But too many people eat non-oily fish such as catfish, Lavie noted. "And they have it fried, which reduces its health benefits," he added.

His review did turn up a few negative studies, including one showing no benefits of omega-3 fatty acids in people who had heart attacks. But it was a relatively small (4,000 people), short (one-year) trial, and the patients in the trial were already getting intensive drug therapy including clot-busting clopidogrel, cholesterol-lowering statins, beta blockers and ACE inhibitors, Lavie noted.

Set against that one trial are the many larger studies cited by Lavie, and epidemiological evidence showing that populations such as Asians and Alaskan Eskimos, whose diets are rich in fish oil, have a low incidence of cardiovascular disease.

The picture is not complete, the new report noted. Studies still must be done to determine the relative benefits of DHA and EPA, the long-chain fatty acids in the omega-3 family. And the American Heart Association says that Omega-3 supplements should be taken only after consulting with a doctor, because too much can cause excessive bleeding in some people.

Another study now in the recruiting stage will test omega-3 fatty acids to prevent not only cardiovascular disease but also cancer, said Dr. JoAnn Manson, chief of preventive medicine at the Harvard-affiliated Brigham and Women's Hospital.

She is a leader of the trial, which is now recruiting 10,000 men aged 60 and older and 10,000 women aged 65 and older. The researchers will test not only the effect of omega-3 fatty acids but also of vitamin D.

Both are "very promising nutrients in prevention of cardiovascular disease, cancer and other chronic diseases," Manson said. In the five-year trial, a quarter of the participants will take both vitamin D and omega-3 fatty acids, a quarter will take the vitamin, a quarter will take the fatty acids and a quarter will take a placebo.

Enthusiasts shouldn't anticipate the results of the trial and start taking large doses of omega-3 fatty acids, Manson warned. "It's too early to jump on the bandwagon and take megadoses, but moderate doses seem reasonable," she said.

More information

Get the official view of the value of omega-3 fatty acids from the American Heart Association  .

WEDNESDAY, July 29 (HealthDay News) -- Food that beckons from the organic aisles of grocery stores may not be any better for you than what lines the rest of supermarket shelves.

According to a British review of studies done over the past 50 years, organic and conventionally produced foods have about the same nutrient content, suggesting that neither is better in terms of health benefits.

"We did not find any important differences in nutrient content between organically and conventionally produced foods," said study author Alan Dangour, a registered public health nutritionist with the London School of Hygiene and Tropical Medicine.

Nonetheless, the researchers noted, organic foods continue to grow in popularity. In the United Kingdom, the market share for organic foods increased 22 percent from 2005 to 2007, they said.

Likewise, the market for organic foods in the United States has grown at about a 20 percent rate each year since 1990, reaching $13.8 billion in consumer sales in 2005, according to the Organic Trade Association. That represents 2.5 percent of total food sales in the country, the trade group noted.

"As a registered dietitian, it is good to see that a systematic review of the literature supports what has long been believed -- that the nutritional content of traditionally grown foods and organic foods are comparable," said Connie Diekman, director of university nutrition at Washington University in St. Louis and past president of the American Dietetic Association. "This report provides confirmation for consumers that if they choose conventionally grown foods or organic foods they will be meeting their nutritional needs."

The review zeroed in on 162 studies that dealt with the nutrient content of foods. Only 55 were of what the researchers considered to be "satisfactory quality" -- a strong indicator that, overall, the science on the subject is not up to snuff.

They found no noted differences between conventional and organic crops with regard to vitamin C, magnesium, calcium, potassium, zinc and copper content. Organic crops did have higher levels of phosphorus, and conventionally produced crops had higher levels of nitrogen.

No differences in nutrient content were indicated in the livestock studies, according to the review.

The Oregon-based Organic Center, which promotes organic food, conducted a similar review of the literature, said Charles Benbrook, chief scientist for the Center. That study yielded results similar to those in the British study, but it also found higher levels of healthy antioxidants and polyphenols in organic foods.

"Given that some of the most significant differences favoring organic foods were for key antioxidant nutrients that most Americans do not get enough of on most days, we concluded that the consumption of organic fruits and vegetables, in particular, offered significant health benefits, roughly equivalent to an additional serving of a moderately nutrient dense fruit or vegetable on an average day," Benbrook said.

And there's another aspect to the organic vs. conventional food debate, said Sheah Rarback, director of nutrition at the Mailman Center for Child Development at the University of Miami Miller School of Medicine.

"You have to also look at what you're not getting" with organic foods, she said. "Maybe it's not a big difference nutritionally, but conventional products may have more pesticides."

And that's a particularly important issue for children, she said.

"We know that young children are getting the nutrition, whatever choice they make, but we also have to look at the pesticide issue," Rarback said. "A study published in Environmental Health Perspectives found that children eating conventionally grown fruit had pesticide residue in their urine, which decreased after just five days on an organic diet."

The production of organic food is subject to a variety of regulations, including those that govern the use of pesticides and other chemicals in fruits and vegetables and the use of medicines in animals, the authors of the review noted in their study, which will be published in the September issue of the American Journal of Clinical Nutrition.

Rarback indicated that the ability to get solid research on organic versus conventionally produced products is hampered by variations in the production process.

"There are so many variables," she said. "Where is something grown? Where is it shipped from? How long was it on the truck? There are going to be variables in terms of nutrition just from production methods."

More information

There's more on food and the nutrients in food at the United States Department of Agriculture.

WEDNESDAY, July 22 (HealthDay News) -- When it comes to weight control, it might not be the kind of snack that matters, but who eats it.

When researchers gave similarly "sinful" snacks to obese and non-obese women, the healthy-weight women wanted less of the treat over time, but obese women kept wanting more.

"Obese and non-obese women respond to high-energy, high-density snacks in different ways," said Jennifer Temple, lead author of the study, which appears in the August issue of the American Journal of Clinical Nutrition. "For us, this underscores a need for really doing detailed studies comparing obese and non-obese women in terms of how they respond to food to try to understand things that work better to improve healthy eating."

"You can't take what you see in non-obese women and think it will automatically have the same effect in obese women," added Temple, an assistant professor in exercise and nutrition science at the University at Buffalo, in New York.

Such information could one day be useful in tailoring dieting strategies for different people.

According to background information in the study, only 10 percent of people who lose weight through dieting and exercise manage to keep that weight off for five years.

Scientists have postulated that one reason for the high failure rate is that people feel deprived of their favorite foods and end up making up for their period of abstinence.

In an earlier study, the same research team had found that "food reinforcement," the term they use to describe motivation to eat, decreased in non-obese women who were asked to consume their favorite snack, be it M&Ms or Oreo cookies, for days at a time.

"After two weeks of eating the same snack food, the women came back into the lab and said, "I don't ever want to see a potato chip again,'" Temple said. "They had no interest in working for the food."

But 300 calories is a large portion, so the researchers decided to do a similar study but with smaller (100-calorie) portions as well as the large portions. In addition, a third group of women consumed no snack calories. The study included 31 obese and 27 non-obese women.

All participants were asked to "work" for their food by performing tasks on a computer program set up as a sort of slot-machine. When all of the shapes on the screen matched, volunteers earned points toward eating.

The women were given pre-packaged portions of their favorite snack to eat every day for two weeks. Snacks tended to fall into one of two categories: high-fat and high-sugar (cookies, candy bars) or savory, meaning just high in fat (such as potato chips).

"For the zero and 100-calorie portions, the obese and non-obese groups looked the same," Temple said. "The food reinforcement didn't change before and after the two weeks, which would be expected."

However, non-obese women who snacked on 300-calorie portions exhibited no increase in motivation to eat, but motivation did increase in obese women who consumed the larger portion, the study found.

"They actually worked harder for the food," Temple said. "This was surprising to us. We had anticipated in the beginning that we might not see a decrease or as large of a decrease, but we didn't expect to see an increase."

In some cases, women reported still wanting the food even though they didn't like it.

The pattern is strikingly similar to that seen in drug addicts.

"We're exploring this idea of sensitization, which happens with drug use," Temple said. "Response to a drug will actually decrease over repeated use."

And that leads to more drug use.

"I stop short of calling overeating an addiction," she added. "I don't think it has all of the same properties, but I think we can learn something about overeating behavior from the drug world. We're applying the same experimental paradigms to food and trying to see if obese people might be more susceptible to having an increased response to repeated food administration."

Marianne Grant, a registered dietitian and health educator with the Texas A&M Health Science Center's Coastal Bend Health Education Center in Corpus Christi, said that something else could be at work.

"This suggests to me that people who were obese were not eating out of hunger," Grant said. "There was some other need that eating was filling for them."

"Everyone is different and approaches eating in a different way," she said. "What works for one person may not work for another person. Overeating may be because of some reason other than hunger. That issue needs to be addressed."

More information

The American Dietetic Association has more on healthy eating  .

SATURDAY, July 4 (HealthDay News) -- While baby boomers are not as young as they used to be, exercise is just as important as ever, but certain precautions are in order to stay injury-free.

"As boomers age, they should take extra steps to protect themselves from injuries when exercising," Dr. Ray Monto, a spokesman for the American Academy of Orthopaedic Surgeons, said in a news release. "A little extra stretching before and after exercise, for example, goes a long way."

To avoid becoming one of the 166,000 people between the ages of 45 and 64 who needed medical help for exercise- and exercise equipment-related injuries last year, the association offers boomers these suggestions:

• Before starting any exercise program, have your doctor check that your heart and body are in good condition and make recommendations based on your age and fitness level.
• Stretch and do three to five minutes of light exercise to warm up at the start.
• Exercise and rest regularly for maximum benefit. Daily moderate exercise is better, and less likely to cause injury, than overdoing it on weekends. Listen to your body, though, and rest or change your workout to meet your physical condition.
• Get a balanced, total body workout by mixing in cardio, strength training and flexibility training. This will also help prevent injuries from overuse. Introduce changes to your routines, such as new exercises, gradually and take lessons when possible to learn proper form and technique.
• Take calcium and Vitamin D supplements daily to help keep bones strong and healthy.

More information

The National Institute on Aging has more about exercise for older adults.