Epidemiological and Clinical Trial Evidence for the Relationship Between Type of Fat and CVD Risk. Dietary Fatty Acids & Cardiovascular Health.
Epidemiological and Clinical Trial Evidence for the Relationship Between Type of Fat and CVD Risk. Dietary Fatty Acids & Cardiovascular Health.
Year: 2000
Authors: F Sacks.
Publication Name: Meeting of the American Heart Association. June 5-6, 2000. Reston, Virginia.
Publication Details: Page 2.
Abstract:
Large prospective studies in the US, the Nurses Health Study in women, and the Health Professional Follow-up Study in men reported that the greatest risk reduction was associated with polyunsaturated fat intake, followed by monounsaturated fat. Both n-6 (linoleic acid) and n-3 (alpha linolenic acid) PUFAs were protective. Replacing saturated fat with carbohydrate was not associated with reduced risk. Trans-fatty acids were strong predictors of increased coronary risk compared to saturated fat or carbohydrates. The beneficial association of polyunsaturated fats in prospective epidemiological studies is consistent with results from randomized clinical trials of diet therapy. In the 1960s and ‘70s, standard dietary therapy used polyunsaturated vegetable oils to lower cholesterol in the context of an overall improved dietary pattern. Three out of four randomized trials found reduction in coronary rates. Thus, there is much support for the use of polyunsaturated oils to replace saturated fats to prevent coronary disease. A Mediterranean diet (Lyon Heart Study) and a vegetarian diet (Indian Heart Study) were both shown in clinical trials to prevent fatal and nonfatal cardiovascular events after myocardial infarction. In both trials, saturated fats were replaced with monounsaturated fats and alpha-linolenic acid, an omega-3 polyunsaturated fatty acids that is present in canola (rapeseed) oil. Vegetables and fruits were increased in the diet as well. Fish of fish oil (DART, GISSI) reduced death after myocardial infarction in 2 trials (DART, GISSI). There are no randomized clinical trails of a low-fat diet that showed a reduction of coronary rates. The published trails are unable to satisfactorily address the issue since they were either too short in duration, e.g. 2-3 years, too small in sample size, produced very little reduction in serum cholesterol, or included other treatments such as anti-hypertensive or anti-lipidemic medications. In summary, epidemiology and clinical trials support using unsaturated fat, mono, n-6 poly and n-3 poly, perhaps in combination, to prevent coronary diseases, in the context of an overall healthy dietary pattern rich in plant foods. (Authors’ Abstract. Editors’ Note: The author reviews epidemiological and clinical trial evidence which supports the inclusion of oils in the diet such as flax in order to reduce CVD risk. This recommendation is made basis the fact that SFA have consistently been shown to increase CVD risk while MUFA and PUFA show an opposite effect.)
