Fish-Oil Supplements Plus Regular Aerobic Exercise Benefit Overweight Patients

May 23, 2007 — In overweight patients, fish oil supplements and regular aerobic exercise reduced body fat and improved cardiovascular and metabolic health, according to the results of a study published in the May issue of the American Journal of Clinical Nutrition.

"Regular exercise and consuming long-chain n-3 fatty acids (FAs) from fish or fish oil can independently improve cardiovascular and metabolic health, but combining these lifestyle modifications may be more effective than either treatment alone," write Alison M. Hill, from the University of South Australia in Adelaide, and colleagues. "Although several studies have investigated the potential for regular aerobic exercise to independently improve body composition and CVD [cardiovascular disease] and metabolic risk factors, few properly controlled studies have investigated the effect of n-3 FA supplementation on these risk factors, particularly body composition."

In this study, 75 overweight volunteers (body mass index [BMI], > 25 kg/m2) with high blood pressure, cholesterol level, or triacylglycerol level were randomized to 1 of the following interventions: fish oil (6 g of tuna fish oil per day), fish oil and exercise, sunflower oil (control; 6 g of sunflower oil per day), or sunflower oil and exercise. The exercise intervention consisted of walking 3 days per week for 45 minutes at 75% of age-predicted maximal heart rate. Plasma lipids, blood pressure, and arterial function were evaluated at 0, 6, and 12 weeks, and body composition was evaluated by dual-energy x-ray absorptiometry at 0 and 12 weeks only.

Compared with the sunflower oil groups, the groups receiving fish oil supplementation had lower triacylglycerol levels, increased high-density lipoprotein (HDL) cholesterol levels, and improved endothelium-dependent arterial vasodilation (P < .05). Compared with the groups not receiving the exercise intervention, those in the exercise groups had better arterial compliance (P < .05). Both fish oil and exercise were independently associated with reduced body fat (P < .05).

"FO [fish oil] supplements and regular exercise both reduce body fat and improve cardiovascular and metabolic health," the authors write. "Increasing intake of n-3 FAs could be a useful adjunct to exercise programs aimed at improving body composition and decreasing cardiovascular disease risk."

The compliance rate was greater than 85%, suggesting that the intervention was well tolerated, probably because of the modest level of physical activity required and because subjects did not need to change their background diet.

"Thus compliance may be sustainable in the longer term," the authors conclude. "Future research should evaluate the efficacy of this combined intervention over a longer duration and investigate the mechanism underlying the improvements in body composition."

A University of Adelaide postgraduate award supported this study. Fish oil and placebo capsules were donated by Nu-Mega Ingredients Pty Ltd. The authors have disclosed no relevant financial relationships.

Am J Clin Nutr. 2007;85:1267-1274.

Source: http://www.medscape.com/viewarticle/557115?src=mp