Did eating eggs increase risk for heart attacks, coronary heart disease or stroke?

An egg a day may be fine for you after all, a new study says.

"Moderate consumption -- up to one egg per day -- is not associated with increased risk of cardiovascular disease," said study author Dr. Frank Hu, who chairs the department of nutrition at Harvard University's T.H. Chan School of Public Health.


The research team analyzed data from large, longitudinal studies that were following 215,000 women and men who had no major chronic disease at the start of the study. 

To verify the results, the team did a meta-analysis of studies from Europe, Asia and the United States. Combined, the studies looked at the egg-eating habits of 1.7 million people and found that eating up to one egg a day had no negative impact on heart health. The only association between a higher intake of eggs and cardiovascular risk was for people with type 2 diabetes.

In fact, moderate egg consumption was associated with a slightly lower risk for heart disease in Asian populations, possibly because of the way Asian food incorporates eggs into recipes rather than eating them separately. The dietary models that recommend replacing full-fat milk, unprocessed red meat or processed red meat with eggs showed a benefit in terms of cardiovascular disease risk.

For a mere 75 calories, an egg delivers 7 grams of high-quality protein, 5 grams of fat and 1.6 grams of saturated fat, along with iron, vitamins, minerals and disease-fighting nutrients like lutein and zeaxanthin. In addition, eggs are affordable, making them a cheap nutritional powerhouse for families with limited food budgets. But one large egg can deliver about 185 milligrams cholesterol. Nutritional guidelines used to recommend an upper limit of 300 milligrams of cholesterol a day. Today the guidelines suggest eating as little as possible by keeping saturated fats to less than 10% of daily calories.

"Nutrition is more dynamic than many other areas of research because the relationship between dietary factors and health outcomes tend to change, for example with type 2 diabetes," Hu said.

"So when we make recommendations on egg consumption, the metabolic conditions and health conditions need to be considered as well."