Dietary fat and coronary disease in US men

Nutrition Research Newsletter, Sept, 1996

Intemational comparison studies have associated diets high in saturated fat and cholesterol and low in polyunsaturated fat witll increased risks of coronary heart disease. Although the effect of dietary factors on blood cholesterol concentrations provides a plausible mechanism for this association, prospective epidemiological studies and randomized trials have not always confirmed the relationship. This report, from the Harvard School of Public Health, describes the relationship between fat and cholesterol intake and coronary risk in a large prospective study of US men.

As part of the Health Professionals Follow-up Study, 43,757 men aged 40-75 years and free from diagnosed cardiovascular disease completed food frequency questionnaires in 1986. During six years of follow-up, 734 myocardial infarctions (including 229 deaths) occurred in the study cohort.

Significant positive associations were observed between intakes of saturated fat and cholesterol and the risk of coronary heart disease. These associations were greatly attenuated after adjustment for dietary fiber intake. An independent inverse relation was observed between intake of linolenic acid and the risk of coronary disease.

These findings "do not support the strong association between intake of saturated fat and risk of coronary heart disease suggested by international comparisons....Although a direct association between saturated fat intake and risk of coronary disease has been reported in several studies, those findings may have been confounded by fibre intake....Benefits of reducing intakes of saturated fat and cholesterol are likely to be modest unless accompanied by an increased consumption of foods rich in fibre." The apparent protective effect of linolenic acid, an n-3 polyunsaturated fatty acid found in plant foods, needs further investigation.

Alberto Ascherio, Eric B Rimm, Edward L Giovannucci, Donna Spiegelman, Meir Stampfer, and Walter C Willett, Dietary Fat and Risk of Coronary Heart Disease in Men: Cohort Follow Up Study in the United States, BMJ313(7049):84-90(13 July 1996) [Correspondence: Dr Alberto Ascherio, Harvard School of Public Health, Boston MA 02115]