Summary: In a randomized, double-blind, placebo-controlled study involving 50 subjects, regular moderate exercise was found to enhance the anti-inflammatory effects of fish oil, thereby reducing the risk of
cardiovascular disease. Subjects were randomized to either receive DHA-rich fish oil (6 g/day, containing 2 g omega-3 fatty acids, 1.6 g DHA), or a placebo (sunflower oil - 6 g/day), for a period of 12 weeks. Subjects were also randomized to either participate in regular moderate exercise (walking 45 min/day, 3 days/week, at 75% maximum heart rate), or to maintain their usual physical activity, for a period of 12 weeks. Researchers set out to examine the combined effect of DHA-rich fish oil supplementation and regular exercise on immune function, particularly in persons with risk factors for
CVD. Results found that while fish oil supplementation decreased superoxide anion production from stimulated blood neutrophils (and this change was negatively correlated with the incorporat ion of DHA into erythrocytes), exercise did not. Regular exercise helped maintain neutrophil bactericidal activity, which was decreased in non-exercising subjects. No significant effects were observed on cytokine production by T cells and monocytes or on neutrophil chemotaxis and adherence. The authors conclude that, "∑the combination of moderate exercise and fish oil supplementation, which reduces cardiovascular risk, may also help to counteract inflammation."