Fish oil plus exercise may banish body fat

People looking to shed body fat might want to follow their workouts with a few capsules of fish oil, if preliminary research is correct.

In a study of overweight adults, Australian researchers found that a combination of exercise and fish oil supplements was effective at reducing body fat and improving cholesterol levels and blood vessel function.

Study participants who took fish oil, alone or with exercise, saw their levels of "good" HDL cholesterol go up, while their triglycerides (an unhealthy form of blood fat) took a dip. Meanwhile, both exercise and fish oil seemed to cut body fat.
The overall benefits, according to the study authors, suggest that a combination of exercise and fish oil may improve overweight adults' cardiovascular health.

Peter R. C. Howe and colleagues at the University of South Australia in Adelaide report the findings in the American Journal of Clinical Nutrition.

Numerous studies have shown that the omega-3 fatty acids in fish may benefit the heart, by lowering blood pressure and triglycerides, reducing the risk of blood clots and improving blood vessel function.

There's also evidence from lab studies that fish oil affects metabolism in a way that can reduce body fat, but the little research that has been done in humans has yielded conflicting findings, according to Hill's team.

For their study, the researchers randomly assigned 75 overweight adults to one of four groups: one that took 6 grams of fish oil per day; one that consumed fish oil and walked for 45 minutes three days per week; one that consumed pills containing sunflower oil; and a fourth that combined sunflower oil and walking.

After 12 weeks, the researchers found, volunteers who were taking fish oil showed greater improvements in their blood fats and blood vessel function than those who took sunflower oil.

What's more, exercise and fish oil each helped reduce body fat.

"Increasing intake of (omega-3 fatty acids) could be a useful adjunct to exercise programs aimed at improving body composition and decreasing cardiovascular disease risk," Howe and his colleagues write.

However, they point out, this is the first clinical trial to look at the cardiovascular and weight benefits of combining fish oil with exercise. More research is needed to investigate the long-term effects, the researchers conclude.

SOURCE: American Journal of Clinical Nutrition, May 2007.