TUESDAY, Oct. 7 (HealthDay News) -- A fatty acid found in olive oil and other heart-healthy monounsaturated fats wards off hunger pangs, a new study suggests.

The findings might one day lead to the development of new drugs to limit, or even enhance, appetite, the researchers said.

Daniele Piomelli, a professor of pharmacology at the University of California, Irvine, and his colleagues infused the fat -- called oleic acid -- into the intestines of laboratory rodents and found that it was converted into a fat messenger called oleoylethanolamide (OEA).

"This OEA activates a receptor protein causing a specific type of satiety," Piomelli said. "This protein initiates a series of physiological events that lead to activation of nerves in the intestine."

The result: A message goes up to the brain and tells the body, in effect, that it's full. "This is different than compounds that make you eat less at a given meal," he said.

Piomelli and his team surgically infused the fat directly into the animals' intestines, then measured appetite. "The animals eat less," he said.

To further test the mechanism, they injected the fat into mice altered so they couldn't make OEA. "When you infuse the fat into these mice, they don't get the decreased hunger," he said.

The practical application? To someday make a drug that would slow OEA from being broken down in the body, thus extending the feeling of fullness. Likewise, OEA levels might be adjusted to help people who have decreased appetite, Piomelli said.

The findings are published in the October issue of Cell Metabolism.

Roger Clemens, director of regulatory science at the University of Southern California School of Pharmacy and a spokesman for the Institute of Food Technologists, said, "From a basic science perspective, it [the new study] is fascinating. It shows the importance of oleic acid."

And while the new research confirms previous work, Clemens said the practical applications remain in the future.

But he added this caution: Eating extra olive oil isn't a route to curbing hunger. While considered a heart-healthy fat, it contains calories that can add up quickly.

More information

For more on olive oil, visit the American Dietetic Association  .

WEDNESDAY, Oct. 1 (HealthDay News) -- Women with a history of dieting or other practices that restrict their eating habits may be more vulnerable to gaining too much or too little weight during pregnancy, a new study finds.

University of North Carolina researchers, in a study of more than 1,200 women, found these previously restricted eaters tended to gain more than the recommended amount of weight if they were either normal, overweight or obese at the start of pregnancy. Restricted eaters who were underweight at the start of their pregnancy tended to gain less than the recommended amount.

The study, published in the October issue of the Journal of the American Dietetic Association, based the desired weight gain amounts on recommendations made by the Institute of Medicine. The institute says women should gain 28 to 40 pounds if they are underweight, 25 to 35 pounds if normal weight, 15 to 25 pounds if overweight, and at least 15 pounds if obese.

"During pregnancy, it would be useful to target these women with similar nutritional and physical activity strategies in order to avoid excessive weight gain and adverse pregnancy outcomes such as Caesarean sections, Macrosomia, and large-for-gestational age [LGA], as well as shorter duration of breast-feeding and higher weight retention in the postpartum period," study co-author Anna Maria Siega-Riz said in a news release issued by the publisher.

More information

The U.S. Department of Health and Human Services has more about having a healthy pregnancy.

TUESDAY, Sept. 30 (HealthDay News) -- The popular supplements glucosamine and chondroitin are no better than a placebo at preventing cartilage loss in knees of people with the form of arthritis caused by wear and tear, a new study found.

Still, the researcher who led the study said glucosamine may help some people with osteoarthritis.

The researcher, Dr. Allen D. Sawitzke, an associate professor of internal medicine at the University of Utah School of Medicine, also acknowledged that the trial wasn't conclusive because of the small number of participants and the relatively short duration -- two years.

Sawitzke said that what struck him as possibly significant was the lower rate of joint loss for participants taking only glucosamine -- 0.013 millimeters, about one-tenth as much as found in those taking either other supplements or a placebo.

"That is not statistically significant, but it hints to me that there might be something going on," he said.

"It was a null study that didn't show a difference," Sawitzke admitted, before adding: "That's not the same as saying there is no difference. The result was influenced by the slow rate of progression for everybody. The study actually says more about what we need to do for the next investigation than for what patients should do."

The new findings, published in the October issue of the journal Arthritis & Rheumatism,, was a continuation of the earlier Glucosamine/chondroitin Arthritis Intervention Trial (GAIT), led by University of Utah researchers.

Arthritis sufferers take glucosamine either to reduce pain or to slow progression of the condition, Sawitzke said. "Controls pain -- this study says nothing about it," he said. "Slows progression -- the study says we weren't able to show that."

For the new study, GAIT participants were given the chance to continue their original study treatment for an additional 18 months, for a total of two years -- 500 milligrams of glucosamine three times a day; 400 milligrams of chondroitin sulfate three times a day; or a combination of the two supplements; 200 milligrams of the pain killer celecoxib (Celebrex) daily; or a placebo.

X-rays were taken at the start of the study and again at one and two years. Joint space width was measured on 581 knees from 357 patients. None of the trial groups showed significant improvement. But the group taking glucosamine had the least change in joint space width, followed by the groups taking chondroitin, celecoxib, a placebo, and the combination of both supplements, the study found.

If someone with arthritis asked his advice about taking glucosamine, Sawitzke said, "I would ask you why you want to. If it is pain, I would try it for a month and, if you felt better, continue. If it is to slow progression, I would say there is insufficient data. It might be years before you know if there is benefit or no benefit."

Andrew Shao, vice president for science and regulatory affairs at the Council for Responsible Nutrition, the supplement industry trade group, said the study "has some severe limitations, because the decline in joint space was much less than the researchers expected."

"The message for consumers," Shao added, "is that this study doesn't provide us with any meaningful insight whatever, and people should continue to use their products."

Previous studies have not been favorable for glucosamine. A Dutch report earlier this year said the supplement didn't help people with arthritis of the hip. And a 2007 review of 15 studies found no convincing evidence that glucosamine works against arthritis.

The picture remains unclear, Sawitzke said.

"I'd hate to give up on something that might have benefit across the board, but at the same time, we don't have evidence that it's there yet," he said.

More information

Learn more about osteoarthritis and its treatment from the U.S. National Library of Medicine.

SATURDAY, Sept. 27 (HealthDay News) -- People who play football and other fall sports are at increased risk for lower extremity injuries and need to take precautions to protect themselves, says the American Podiatric Medical Association (APMA).

"Stress fractures of the foot, ankle sprains and ligament injuries are all, unfortunately, quite common in popular fall sports such as football," Dr. David Davidson, podiatric medical consultant for the Buffalo Bills of the National Football League, said in an APMA news release. "From maintaining proper conditioning to wearing sport-specific footwear, athletes can function at peak performance much more often when constantly maintaining high levels of footwear safety."

Sprains, fractures and turf toe are among the most common acute injuries suffered by people playing fall sports.

Sprains (stretched or torn ligaments) can be caused by hard sprinting. Prevention includes doing proper warm-up exercises before and after workouts, practices and games. Spend five to 10 minutes stretching, holding and relaxing muscles. Sprains that don't show improvement in three days should be looked at by a doctor. Treatment may include casting, immobilization and a rehabilitation program, the APMA said.

Casting, and sometimes surgery, is required to properly immobilize fractures and set breaks. It usually takes 10 to 12 weeks to recover. You can reduce your risk of stress fractures (incomplete fractures in bones typically caused by overuse) by wearing sport-specific footwear that contains extra padding.

Turf toe is a painful hyperextension of the big toe joint. Competing on artificial turf is the leading cause of this condition, but it can also occur on grass and other natural surfaces, the APMA said. Customized foot orthotics can help protect against turf toe and wearing a stiffer shoe can prevent further aggravation of the condition. Treatment of turf toe usually includes rest, ice, compression and elevation (RICE).

More information

The American Academy of Orthopaedic Surgeons has more about foot and ankle injuries  .