Elevation of lipid levels in the blood contributes to postmenopausal women's risk for cardiovascular disease(CVD). Most previous studies of the use of fish-oil supplementation to lower blood lipids have used male subjects. For their study published in The American Journal of Clinical Nutrition, Stark et al. chose a group of postmenopausal women either receiving or not receiving hormone replacement therapy (HRT). In a placebo-controlled double blind trial, 35 postmenopausal women, half receiving HRT, were randomly assigned to receive 8 capsules per day of either n-3 fatty acid enriched supplement (fish-oil consisting of 2.4 g of eicosapentaenoic acid plus 1.6 g docosahexaenoic acid) or placebo oil (control). At the end of the 28-day trial, supplementation with n-3 fatty acids had lowered serum triglycerides by an average of 26% in the subjects who took the fish-oil and reduced the overall ratio of triglyceride to HDL by 28%. However, triglyceride reduction was less in women on HRT,19%, than in women not taking HRT, 36%.
Recent studies have shown that serum triglycerides pose an independent risk factor for CVD, unrelated to HDL:LDL ratios. The possibility that elevated triglycerides may be a more important risk factor for myocardial infarction in women than in men has also been reported previously. Two recent studies of women receiving HRT showed no beneficial effect on CVD risk despite improvements in their HDL:LDL ratios. In both studies, significant increases in triglyceride were reported with HRT. Fish oils containing n-3 fatty acids have been shown to specifically reduce triglyceride concentrations in humans; consequently, supplementation with fish-oil could benefit women, even if they are receiving HRT.
Future studies will help to elucidate the interactions between fish-oil therapy and HRT while determining the long-term effect of n-3 fatty acid supplementation on postmenopausal women.
Stark, Ken D et al. Effect of fish-oil concentrate on serum lipids in postmenopausal women receiving and not receiving hormone replacement therapy in a placebo-controlled, double-blind trial. Am. J. Clin Nut 2000;71:389-94.
For more information please contact Dr. Bruce J. Holub at bholub@uoguelph.ca
This media release is provided by The American Society for Clinical Nutrition, to provide current information on nutrition-related research. This information should not be construed as medical advice. If you have a medical concern, consult your doctor.
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Journal
American Journal of Clinical Nutrition