A new study finds that a consumption of up to one egg a day does not increase the risk of stroke.
Eggs are somewhat of an unsettled issue in modern nutrition: on the one hand, they have a wealth of valuable nutrients, but on the other hand, they also contain cholesterol and have been traditionally regarded as hazardous for cardiovascular health. Eggs have remained a controversial issue, with studies often finding contradictory results.
Now, a new effort finds that in low quantities (about 1 per day), eggs don't seem to have any detrimental effect on the heart or blood pressure. In fact, there was a small inverse correlation between blood pressure and egg consumption.
The study analyzed the dietary habits of 1,950 Finnish men between 42 and 60 years old with no history of cardiovascular disease. The study also looked at carriers of a particular protein called E phenotype 4. This protein combines with fats (lipids) in the body to form molecules called lipoproteins. Lipoproteins are responsible for packaging cholesterol and other fats and delivering them through the bloodstream. People who carry this hereditary variant are particularly vulnerable to the effects of cholesterol. Finnish people are unusual in this regard: their prevalence of this variant is exceptionally high, affecting around 1 in 3 people. Presumably, if eating one egg a day would cause heart issues, you'd see it in this population first.
However, the study found that moderate egg consumption, even daily, does not seem to be associated with greater risk of stroke -- even in people who are predisposed to the effects of cholesterol. While this is encouraging news for egg-lovers, it also shouldn't be generalized: it all greatly depends on your total cholesterol intake (in this study, eggs represented an overall 25% of total cholesterol consumption). If your diet is rich in cholesterol and fats, then egg consumption can be the proverbial straw that breaks the camel's back. Furthermore, the generalizability of this study is also weakened fact that the population in this study had no cardiovascular conditions or diseases, researchers say.
Nutrition is an amazingly complex topic, and eggs, in particular, are far from a settled issue. As it is so often the case, maintaining a balance is key. Overall, the research seems to indicate that, at least in a healthy diet, eggs can play a useful and important role. In other words, as long as you don't eat too many saturated fats (butter, cheese, meats), you'll probably be okay.
Journal Reference: Abdollahi et al. Egg consumption, cholesterol intake, and risk of incident stroke in men: the Kuopio Ischaemic Heart Disease Risk Factor Study. The American Journal of Clinical Nutrition, 2019; DOI:10.1093/ajcn/nqz066