Does Egg Consumption Increase Risk for Heart Disease?

After a colleague asked my opinion on the relationship between egg consumption and cardiovascular disease, I decided to delve further into the topic.

For decades, we’ve been advised to limit egg consumption to reduce our risk of developing heart disease. The reasoning for this is based on the diet-heart hypothesis, which argues eating foods rich in cholesterol and saturated fat increases risk of developing heart disease. Specifically applied to eggs, the argument states: 1) eggs are rich in cholesterol; 2) eating cholesterol has been shown, in some studies, to increase serum cholesterol; 3) high serum cholesterol promotes heart disease. Using this logic, populations with increased egg consumption should have increased rates of heart disease.

First, let’s address the issue of egg consumption and cholesterol. Does eating eggs, which are high in cholesterol, increase serum cholesterol?

One experimental feeding study found a modest increase in serum cholesterol (1-3%) from eating one additional egg per day[1]. However, larger studies found conflicting results.

The Framingham Heart Study compared cholesterol levels of individuals eating the most and least eggs. When comparing the men with highest egg consumption to those with the lowest, there was no difference in serum cholesterol. Women eating the most eggs actually had slightly lower cholesterol than women eating the least eggs[2].

Similarly, the Multiple Risk Factor Intervention Trial found that individuals with cholesterol lower than 200 ate more eggs than individuals with cholesterol greater than 220[3].

Once again, the Third National Health and Nutrition Examination Survey of more than 20,000 participants found that participants eating less than one egg per week had higher serum cholesterol than participants eating more than four eggs per week[4].

Thus, the hypothesis that egg consumption actually increases serum cholesterol is, at best, tenuous. The more important question is does egg consumption actually affect heart disease risk?

A study of 26,000 California Seventh-Day Adventists found no increase in coronary heart events in participants eating the most eggs versus those eating the least[5]. A study of 5,000 Finish men and women found no effect of egg consumption on death rate from coronary heart disease[6]. The Fakuoka Heart Study examined 660 heart attack patients and found no association between egg consumption and heart attack risk[7]. An Italian case-controlled study found no effect of egg consumption on heart attack risk