BOSTON, MASSACHUSETTS. Several studies have found a clear inverse association between the consumption of fish and fish oils and the risk of coronary heart disease (CHD) and sudden cardiac death. However, it is not known whether this protective effect extends to diabetes patients. Researchers at the Harvard Medical School have conducted a study to examine this. Their study included 5103 female nurses with diabetes, but free of cardiovascular disease and cancer at entry. Between 1980 and 1996 there were 362 cases of CHD (7.1%) and 468 deaths from all causes in the study group (9.2%). The causes of death were CHD or stroke – 161, cancer – 172, and other causes – 135.
Study participants completed detailed food frequency questionnaires in 1980, 1984, 1986, 1990 and 1994. The researchers noted a strong correlation between the risk of CHD and fish intake. Women who consumed fish once a week had a 40% lower risk of CHD than did women who consumed fish less than once per month. Eating fish 5 times per week reduced CHD risk by 64% and overall mortality by 52%. Only dark-meat fish (mackerel, salmon, sardines, bluefish, and swordfish) and shrimp, lobster and scallops showed a beneficial effect. The researchers also calculated the amount of fish oils (eicosapentaenoic acid and docosahexaenoic acid) obtained from the diet and found that study participants with an average intake of just 250 mg/day had a 31% reduction in CHD and a 37% reduction in death from all causes compared to participants with a low (40 mg or less) daily intake. The researchers note that supplementation with fish oils does not impair glycemic control and suggest that regular fish consumption or fish oil supplementation should be considered as an integral part of a healthy diet for the management of diabetes.
Hu, Frank B., et al. Fish and long-chain omega-3 fatty acid intake and risk of coronary heart disease and total mortality in diabetic women. Circulation, Vol. 107, April 15, 2003, pp. 1852-57
Grundy, Scott M. N-3 fatty acids: priority for post-myocardial infarction clinical trials. Circulation, Vol. 107, April 15, 2003, pp. 1834-36 (editorial)