Despite recommendations by the major international health agencies to reduce saturated fat intake, debate continues within the scientific community about the relationship between fatty acid intake and coronary heart disease (CHD) risk.
Two good recent articles exemplify this debate. Although both question current dogma regarding dietary fat, they are still consistent with the concept that soyfoods may positively contribute to a heart-healthy diet. Furthermore, there is intriguing evidence that dietary fat detrimentally affects health independent of its effect on CHD risk in ways that emphasize the benefits of soyfoods.1
An article in the British Medical Journal by Astrup et al.,2 co-authored by 16 individuals, challenges the dietary guideline related to fat intake of the World Health Organization, which is to replace saturated fat with polyunsaturated fat (PUFA) and monounsaturated fat. The authors emphasize that this recommendation fails to consider the substantial evidence that the health effects of saturated fat vary depending upon the specific fatty acid and on the specific food source. The latter point relates to the observation that saturated fat from different food sources can differentially impact heart disease risk. Astrup et al.2 argue that a food-based translation of the recommendations for saturated fat intake would avoid unnecessary reduction or exclusion of foods that are key sources of important nutrients.
The other article, by DuBroff and de Lorgeril,3 published in the BMJ Evidence-Based Medicine, noted that 11 of the 22 randomized controlled trials of at least one year in duration that assessed the impact of diet on cardiovascular events, reported statistically significant reductions in serum cholesterol, but none of these reported a mortality benefit and only two reported a reduction in cardiovascular disease (CVD) events. These authors also concluded that the results of meta-analyses that broadly examined the relationship of dietary fat to CVD and/or mortality do not support the diet-heart hypothesis (that diet, serum cholesterol and CVD are causally related) or the recommendation to replace saturated fat with PUFA.