Fish Oil and Moderate Exercise Reduces Heart Disease Risk and Body Fat in Overweight Adults

by | Jul 25, 2008 | Cardiovascular Health, Fitness and Exercise, Obesity

Written by Susan Sweeny Johnson, PhD, Biochem.  Combining moderate exercise and taking 6 gm per day of fish oil appears to significantly improve cardiac health and lower percent body fat in overweight adults.

Fish oil supplementation has been shown to improve cardiovascular health by lowering blood triglycerides 25-20% and raising HDL 10%, lowering blood pressure, lowering platelet aggregation and overall lowering risk of death from heart disease. (1,2,3) Aerobic exercise has also been shown to improve blood lipids, lower blood pressure and improved arterial health. (4) Until now there have been no controlled studies on the combined effect of fish oil supplementation and moderate aerobic exercise in overweight adults that have addressed effects on body fat.

In this study, 67 adults with a body mass index (BMI)* over 25 kg/m2 were divided into four groups:

  • Group 1 took fish oil (6g per day)
  • Group 2 took fish oil and exercised by walking 3 times a week for 45 minutes at 75% of maximum heart rate
  • Group 3 took sunflower oil (6 gm per day)
  • Group 4 took sunflower oil and exercised like Group 2

Participants were assessed for changes in blood lipids, blood pressure, arterial function and body composition at 0, 6 and 12 weeks.

Results showed that fish oil without exercise significantly reduced blood triglycerides and raised HDL as previously reported and as compared to sunflower oil, which showed very little change. Adding exercise did not improve lipids further. Blood pressure did not show significant improvement with either oil or exercise during the length of this trial. However, arterial function measured as elasticity of small arteries improved about 25% with the addition of exercise to either oil regimen. Additionally, percent body fat was reduced significantly when supplementation of fish oil was combined with exercise (about 2.8% over 12 weeks).

Thus, combining moderate exercise (walking at a good pace for 45 minutes three times a week) and taking 6 gm per day of fish oil appears to significantly improve cardiac health and lower percent body fat in overweight adults. This regimen seems to be well tolerated, judging from the high compliance of the participants in this study.

Source: Hill, Alison M., Jonathan D. Buckley, Karen J. Murphy, and Peter RC Howe. “Combining fish-oil supplements with regular aerobic exercise improves body composition and cardiovascular disease risk factors.” The American journal of clinical nutrition 85, no. 5 (2007): 1267-1274.

© 2007 American Society for Nutrition

Posted July 25, 2008.

References:

  1. Mozaffarian D, Rimm EB. Fish intake, contaminants, and human health: evaluating the risks and the benefits. JAMA 2006;296:1885–99.
  2. HowePR, Clifton PM, James MJ. Equal antithrombotic and triglyceride lowering effectiveness of eicosapentaenoic acid-rich and docosahexaenoic acid-rich fish oil supplements. Lipids 1999;34(suppl):S307– 8.
  3. Lungershausen YK, Abbey M, Nestel PJ, Howe PR. Reduction of blood pressure and plasma triglycerides by omega-3 fatty acids in treated hypertensives. J Hypertens 1994;12:1041–5.
  4. Warburton DER, Nicol CW, Bredin SSD. Health benefits of physical activity: the evidence. CMAJ 2006;174:801–9.