Diet, lipids, and coronary heart disease

This review has highlighted some of the experimental studies in animals and humans that have shown an important link between dietary change and atherosclerosis. This relationship was further supported by population studies showing a key role for saturated fat intake in the determination of serum cholesterol level and the prediction of CHD. Recent data linking dietary cholesterol independent of serum cholesterol level to the prediction of CHD were discussed as well. Various components of the diet and their effects on lipid and lipoproteins were reviewed. The chief factors in the diet which raise cholesterol and low-density lipoprotein cholesterol (LDL-c) are dietary cholesterol, saturated fat, and excess calories leading to obesity. Dietary factors useful in lowering cholesterol and low-density lipoprotein cholesterol include monounsaturated fats, polyunsaturated fats, and dietary fiber, which can be substituted for saturated fats. The usefulness of a special class of polyunsaturated oil, the omega-3 fatty acids, in both lowering triglyceride levels and preventing thrombosis was also discussed. Although alcohol raises the HDL-c level, it is not clear that its use offers protection against CHD, and its risks clearly outweigh its advantages in this regard. Regular aerobic exercise is recommended as a healthier alternative to raising high-density lipoprotein cholesterol. Also discussed was postprandial lipemia, which may prove to be another indicator of risk of CHD. Finally, the recent NCEP dietary guidelines were discussed along with practical suggestions as to their implementation.