Epidemiological evidence of relationships between dietary polyunsaturated fatty acids & mortality in the multiple risk factor intervention trial.
Epidemiological evidence of relationships between dietary polyunsaturated fatty acids & mortality in the multiple risk factor intervention trial.
Year: 1992
Authors: T A Dolecek.
Publication Name: P.S.E.B.M.
Publication Details: Volume 200; Page 177.
Abstract:
A large number of studies investigating the effect of polyunsaturated fatty acids (PUFAs) on physiological and disease related mechanisms have been experimental or clinical in nature. Epidemiological investigation of dietary PUFA intakes on disease occurrence would provide additional insight into determining optimal intake levels of these fatty acids. Using data from the Multiple Risk Factor Intervention Trial (MRFIT), the objective of this study was to investigate the effect of dietary PUFA intake on disease outcomes that may relate to PUFA biochemistry. MFRIT was a multi-center clinical trial supported by the National Heart, Lung, and Blood Institute to investigate the primary prevention of coronary heart disease (CHD). 12,866 men (aged 35-57 years) who were determined to be at high risk of developing CHD based upon smoking status, diastolic blood pressure, and serum cholesterol levels comprised the study population. Participants were followed for 6-8 years, in which 24-hour dietary recall was conducted at baseline, and years 1, 2, 3 and 6. Participants were assigned to either a special intervention group (n=6616), who received programs to reduce smoking, blood pressure, and blood cholesterol; or a usual care group (n=6250) who were referred to their usual source of medical care. Both groups returned to clinics on an annual basis for assessment of risk factor status. No significant association was observed between linoleic acid (LA) and mortality. A significant inverse association was observed between ALA intake and mortality from CHD, all cardiovascular diseases (CVD), and all cause mortality. An inverse association was also observed for the sum of fatty acids derived from fish oils (20:5n3 + 22:5n3 + 22:6n3) and CHD, CVD, and all cause mortality. The ratio of ALA to LA was also observed to be inversely related to cancer mortality. These observations support previous findings which demonstrated n-3 fatty acids are protective against CVD. These data also suggest that the composition and balance of PUFA in the diet may influence mortality from CVD and possibly various forms of cancer. Additional research is necessary to define the optimal level and balance of PUFAs in the diet needed to promote heath and prevent disease.
