Dietary fat in relation to risk of multiple sclerosis among two large cohorts of women

Ecologic correlations suggest that higher intake of saturated fat and lower intake of polyunsaturated fat might increase the risk of multiple sclerosi s (MS), but the results of case-control studies have been inconsistent. Bec ause no prospective data are available, the authors examined these associat ions in two large cohorts, the Nurses' Health Study, which consisted of 92, 422 women with 14 years of follow-up (1980-1994) and the Nurses' Health Stu dy II, which consisted of 95,389 women with 4 years of follow-up (1991-1995 ). They documented 195 new cases of MS. The pooled multivariate relative ri sks comparing women in the highest quintile with those in the lowest were 1 .1 (95% confidence interval: 0.7, 1.7) for total fat, 0.7 (95% confidence i nterval: 0.5, 1.2) for animal fat, 1.2 (95% confidence interval: 0.7, 2.1) for vegetable fat, 0.8 (95% confidence interval: 0.5, 1.3) for saturated fa t, 1.1 (95% confidence interval: 0.7, 1.7) for monounsaturated fat, 1.7 (95 % confidence interval 1.0, 2.8) for n-6 polyunsaturated fat, 1.3 (95% confi dence interval: 0.8, 2.0) for trans unsaturated fat, and 0.7 (95% confidenc e interval: 0.4, 1.1) for cholesterol. Omega-3 fatty acids from fish were a lso unrelated to risk. However, the authors observed a nonsignificantly low er risk of MS for a higher intake of linolenic acid. These findings do not support relations between intakes of total fat or major specific types of f at and the risk of MS.