A study from Northwestern University published in March (2019) showed that adults who consumed more eggs had a significantly higher risk of cardiovascular disease and of dying from any cause than those who consumed fewer eggs. Norrina Allen, the study’s co-corresponding author says that dietary cholesterol, regardless of its source, is associated with an increased risk of heart disease. The yolk of one large egg contains 186 milligrams of cholesterol. Other dietary sources are red meat, processed meat and high-fat dairy products such as butter and whipped cream.
The new findings came from data on 29,615 adults who were participating in six observational studies. All responded to a food frequency questionnaire asking what they had eaten during the previous year or month. No information was available on their diets beyond what they provided at the outset, so we don’t know whether their egg consumption declined or increased over the 17.5 years they were followed. During that time, 5,400 of the participants had cardiovascular events, including heart attacks, strokes, and heart failure, and 113 died as a result of cardiovascular disease. All told, 6,132 died from all causes. The researchers reported that the likelihood of cardiovascular disease rose by six percent and the likelihood of early death by eight percent for each additional half an egg eaten per day.
The average egg consumption of many Americans is estimated at three to four per week, and adults in the U.S. get an average of 300 mg of cholesterol per day. The study found that consuming that much cholesterol daily is associated with a 17 percent higher risk of cardiovascular disease and an 18 percent higher risk of all-cause death. The researchers reported that cholesterol was the “driving factor here,” independent of the consumption of saturated fat. They also found that eating three to four eggs per week was associated with a six percent higher risk of cardiovascular disease and an eight percent higher risk of any cause of death.
While this study demonstrates an association between egg consumption and cardiovascular disease, it does not prove cause and effect.
Do these new findings mean you should stop eating eggs? Not even the Northwestern study leader Wenze Zhong, a postdoctoral fellow in preventive medicine, recommends that. He notes that eggs and red meat are good sources of essential amino acids, iron and choline. Instead, of giving up eggs, he suggests eating them in moderation or eating mainly egg whites instead of whole eggs.
You should also know that a study from China with 512,891 participants published in October 2018 found a lower risk of cardiovascular disease among those who ate a moderate amount of eggs (less than one a day) than those who ate no eggs.
There are good reasons to continue consuming eggs for their nutritional benefits. Their yolks contain vitamins A, D, E and K as well as iron. The whites are a good source of protein. Eggs from free-ranging, organically fed hens also give you omega-3 fatty acids needed for optimum health.
The American Heart Association recommends limiting the amount of cholesterol you get from your diet to less than 300 mg daily, but I wouldn’t worry about that. Instead, pay attention to how your eggs are prepared, keeping them free of butter or other forms of animal fat.
Andrew Weil, M.D.
Victor W. Zhong et al, “Associations of Dietary Cholesterol or Egg Consumption with Incident Cardiovascular Disease and Mortality.” JAMA, March 19, 2019 DOI: 10.1001/jama.2019.1572