May/June 2009 Alternative Health
Omega-3 Fish Oils May Reduce Weight

by Jack Challem

Taking omega-3 fish oil supplements may help some people lose body fat and weight - a finding that supports the idea that certain nutrients influence weight, regardless of calorie intake.

According to researchers, omega-3s activate several genes involved in burning fat, shifting metabolism away from the storage to the burning of fat.

Researchers at the University of South Australia in Adelaide asked 81 men and women to take 6 grams of fish oils daily or take the fish oils in combination with light exercise. As a control, some of the subjects took sunflower oil, or they took sunflower oil and engaged in moderate exercise.

The fish oils, obtained from tuna, provided a total of 1,560 milligrams of docosahexaenoic acid (DHA) and 360 milligrams of eicosapentaenoic acid (EPA) daily.

At the end of the 12-week study, the results were striking. The combination of fish oil supplementation and regular exercise significantly reduced body fat, which indicates the potential benefit of a combined treatment strategy for optimizing body composition.

On average, people taking the fish oils and engaging in light exercise lost an average of about 3 pounds of weight.

In addition, the fish oil and exercise independently increased muscle mass, though only slightly. In contrast, people taking the sunflower oil had increases in body fat and decreases in muscle. The combination of sunflower oil and exercise led to negligible improvements.

In a separate study, the French National Institute for Health and Medical Research asked 27 women with type 2 diabetes to take 3 grams of either fish oils or placebos daily for two months. The supplements provided 1.8 grams of EPA and DHA daily.

At the end of the study, women taking the fish oils had lost more body fat and their fat cells had shrunk in size. On average, they lost about 1 pound of weight, whereas people taking placebos had no change in weight.

Women taking the fish oils also benefited from lower blood levels of triglycerides, a risk factor for heart disease.

Finally, researchers from Japan fed different types of diets to obesity-prone laboratory mice. Mice given fish oils as eight percent of their diet gained substantially less weight than animals on either high-fat or low-fat diets.

The researchers determined that the fish oils boosted the activity of several genes involved in burning fat, as well as increasing the metabolism of fats in the intestine.

Jack Challem, one of America's most trusted nutrition and health writers, is the publisher of The Nutrition Reporter newsletter. Visit www.nutritionreporter.com.