Eggs are also loaded with cholesterol—about 200 milligrams for an average-sized egg. That’s more than double the amount in a Big Mac. Fat and cholesterol contribute to heart disease. 

A 2021 study found that the addition of half an egg per day was associated with more deaths from heart disease, cancer, and all causes. For every 300 milligrams of dietary cholesterol consumed per day, mortality risk increased by up to 24%. A study published in JAMA found that that each 300 milligram dose of dietary cholesterol was associated with an increased risk for cardiovascular disease and mortality by 17% and 18%, respectively. When it came to eggs, each half egg caused a 6% and 8% increased risk, respectively. A study in the Canadian Journal of Cardiology found that those who eat the most eggs have a 19% higher risk for cardiovascular problems.

Industry-funded research has downplayed the effects of egg consumption on cholesterol levels. A Physicians Committee review published in the American Journal of Lifestyle Medicine examined all research studies published from 1950 to March 2019 that evaluated the effect of eggs on blood cholesterol levels and examined funding sources and their influence on study findings. Research published prior to 1970 showed no industry influence on cholesterol research. The percentage of industry-funded studies increased over time, from 0% in the 1950s to 60% in 2010-2019. More than 85% of the research studies, regardless of funding sources, showed that eggs have unfavorable effects on blood cholesterol. But 49% of industry-funded publications reported conclusions that conflicted with actual study results, compared with 13% of non-industry-funded trials.