A new study titled “egg consumption and risk of coronary heart disease and stroke: dose-response meta-analysis of prospective cohort studies” appeared in the January issue of the British Medical Journal (BMJ). The study was co-authored by researchers from various Chinese universities and researchers from the Harvard School of Public Health. The authors scoured the literature from 1966 to 2012 for appropriate studies that examined the association between egg consumption and risk of coronary heart disease (CHD). Their primary conclusion: the analysis did not support a relationship between higher egg consumption and elevated risk of CHD and stroke.
When considering potential reasons for their results the researchers pointed out, among other things, that the effects of dietary cholesterol on serum cholesterol levels are relatively small. They also pointed out that overall dietary patterns and saturated fat intake likely have much greater influence on serum cholesterol levels than does dietary cholesterol.
From my perspective, these data uncover an issue with much of the traditional dietary cholesterol advice offered by some public health organizations. When recommendations are made that we eat cholesterol-containing foods judiciously, I believe that this guidance is based on either A) erroneous conclusions that dietary cholesterol itself greatly impacts serum cholesterol levels, or B) conclusions that because most foods high in cholesterol also tend to be high in saturated fat, it is prudent to limit cholesterol intake as a means of keeping overall fat intake low, or C) neglect of the impact that overall diet has on CHD risk.
Regarding point B above, how should one view foods that tend to be relatively high in cholesterol and relatively low in saturated fat- -foods like eggs or shellfish? Based on the BMJ study it appears that these foods tend to get a bit of a “bum rap.” For most folks, dietary cholesterol does not greatly impact serum cholesterol or disease risk, so it seems logical that eating foods of this nature should be perfectly fine, and certainly preferable to high cholesterol/high saturated fat alternatives. Further, regarding point C above, it is important to think about “the company that foods keep” when deciding the place of any individual food in the diet. So thinking about eggs in the context of a meal consisting of yogurt, low fat milk and a fruit cup is far different from a CHD risk perspective than eggs on a plate with high-fat meats and fried or heavily-buttered carbohydrates.
Bottom line- -studies like the recent BMJ study and others like it strongly suggest that dietary cholesterol is not the nutritional “boogeyman” we once thought it was, and that a highly nutritious food like the egg, despite its cholesterol content, can be a great staple in the diet.