The scientists recruited 138 adults 45 men and 93 women who were in good health, but who were either overweight or obese and lived sedentary lives. Their average age was 51 years. Based on body mass index, a measure of weight relative to height, 91 percent of the participants were overweight and 47 percent were obese.
Inflammation tends to accompany excess body fat, so the researchers recruited participants who were most likely high in pro-inflammatory blood compounds at the beginning of the study.
"We wanted to have enough room to see a downward trend. Most other trials testing the effects of omega-3 supplements on inflammation used people who were seriously diseased or skinny and healthy," said Kiecolt-Glaser, also an investigator in Ohio State's Institute for Behavioral Medicine Research (IBMR). "You can see results in people with serious diseases, but there's a lot of other noise in that system. We wanted to make sure we were studying results in people who were fairly fit but who weren't exercising, because exercise can clearly lower inflammation."
The researchers also excluded from participation people taking a variety of medications to control mood, cholesterol and blood pressure as well as vegetarians, patients with diabetes, smokers, those routinely taking fish oil, people who got more than two hours of vigorous exercise each week and those whose body mass index was either below 22.5 or above 40.
Participants received either a placebo or one of two different doses of omega-3 fatty acids either 2.5 grams or 1.25 grams per day. The supplements were calibrated to contain a ratio of the two fish oil fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), of seven to one. Previous research has suggested that EPA has more anti-inflammatory properties than does DHA.
After four months, participants who had taken the omega-3 supplements had significantly lower levels i
|Contact: Jan Kiecolt-Glaser|
Ohio State University