Fish oil plus exercise linked to weight loss
reductions in fat mass by about 1.5 kg, as well as improving heart
health markers, says a new study from Australia.
The study adds to an ever-growing list of potential health benefits from the omega-3 polyunsaturated fatty acids, identified as one of the super-nutrients taking the food and supplements industry by storm. Much of its healthy reputation that is seeping into consumer consciousness is based largely on evidence that it can aid cognitive function, may help protect the heart against cardiovascular disease, and could reduce the risk of certain cancers. "Evidence is limited that fish oil supplementation can reduce body fat in overweight or obese subjects, and, in the studies that do provide evidence, little effort was made to control for the confounding influence of physical activity," wrote lead author Alison Hill in the American Journal of Clinical Nutrition. "The present study is the first properly controlled trial to show an improvement in body composition in overweight or obese subjects after intervention with omega-3 fatty acids and regular aerobic exercise," she added. The researchers, from the University of South Australia in Adelaide, examined the effects of effects of fish oil and exercise, alone and together, on fat mass, lean mass, and cardiovascular health in 75 overweight adults (age range 25-65). The participants all had at least one of the cardiovascular risk factors of mild hypertension, elevated blood triacylglycerols levels, and high total cholesterol levels. Subjects were randomly assigned to receive daily fish oil supplements (260 mg docosahexaenoic acid (DHA) and 60 mg eicosapentaenoic acid (EPA), Hi-DHA, NuMega Ingredients) or placebo (sunflower oil), with or without an exercise regimen. The fish-oil supplements led to a decrease in blood triacylglycerols levels (14 per cent) and an increase plasma HDL cholesterol levels (10 per cent) relative to baseline amounts. The placebo sunflower oil decreased blood triacylglycerols levels and increase plasma HDL cholesterol levels by five and three per cent, respectively. The combination of fish oil and exercise reduced fat mass by 1.6 kg, with no significant changes observed for fish oil alone, or placebo with or without exercise. No significant change in lean mass was observed for any of the groups. "We have confirmed the independent benefits of supplementation with DHA-rich fish oil for triacylglycerols, [and] HDL cholesterol," said the researchers. "We also showed that both fish oil supplementation and regular moderate exercise reduced body fat in overweight or obese subjects who were at risk of CVD." "Future research should evaluate the efficacy of this combined intervention over a longer duration and investigate the mechanism underlying the improvements in body composition," they concluded. The retail market for weight management products was estimated by Euromonitor International to be worth US$0.93bn (€0.73) in Europe in 2005 and $3.93bn in the US, indicating that calls to slim down or face the health consequences is being heeded by a slice of the overweight population at least. Source: American Journal of Clinical Nutrition Volume 85, Pages 1267-1274 "Combining fish-oil supplements with regular aerobic exercise improves body composition and cardiovascular disease risk factors" Authors: A.M. Hill, J.D. Buckley, K.J. Murphy, P.R.C. Howe
