Eggs are among the most nutritious foods on the planet. In fact, a whole egg contains all the nutrients needed to turn a single cell into an entire chicken. However, eggs have gotten a bad reputation because the yolks are high in cholesterol. But cholesterol isn’t that simple.
For this reason, eating too many eggs might be bad for your health. Now, a recent study by the Northwestern Medicine suggests that people who eat an added three or four eggs a week or 300 milligrams of dietary cholesterol per day have a higher risk of both heart disease and early death compared with those who eat fewer eggs.
Egg yolks are high in dietary cholesterol among all commonly consumed foods. One large egg has 186 milligrams of dietary cholesterol in the yolk. Consuming an additional 300 milligrams of dietary cholesterol per day was associated with a 3.2% higher risk of heart disease and a 4.4% higher risk of early death.
Co-corresponding study author Norrina Allen, associate professor of preventive medicine at Northwestern University Feinberg School of Medicine said, “The take-home message is really about cholesterol, which happens to be high in eggs and specifically yolks. As part of a healthy diet, people need to consume lower amounts of cholesterol. People who consume less cholesterol have a lower risk of heart disease.”
Lead author Wenze Zhong, a postdoctoral fellow in preventive medicine at Northwestern said, “Other animal products such as red meat, processed meat, and high-fat dairy products (butter or whipped cream) also have high cholesterol content.”
Eating dietary cholesterol or eggs is linked to cardiovascular disease and death has been debated for decades. Eating less than 300 milligrams of dietary cholesterol per day was the guideline recommendation before 2015. However, the most recent dietary guidelines omitted a daily limit for dietary cholesterol. The guidelines also include weekly egg consumption as part of a healthy diet.
An adult in the U.S. gets an average of 300 milligrams per day of cholesterol and eats about three or four eggs per week.
Scientists noted, “the study findings mean the current U.S. dietary guideline recommendations for dietary cholesterol and eggs may need to be re-evaluated.”
Allen said, “Our study showed if two people had exact same diet and the only difference in diet was eggs, then you could directly measure the effect of the egg consumption on heart disease. We found cholesterol, regardless of the source, was associated with an increased risk of heart disease.”
Scientists examined data from six US study groups including more than 29,615 people followed for 17½ years on average. Over the follow-up period, a total of 5,400 cardiovascular events occurred, including 1,302 fatal and nonfatal strokes, 1,897 incidents of fatal and nonfatal heart failure and 113 other heart disease deaths. An additional 6,132 participants died of other causes.
A major limitation of the study is participants’ long-term eating patterns weren’t assessed.
Allen said, “We have one snapshot of what their eating pattern looked like. But we think they represent an estimate of a person’s dietary intake. Still, people may have changed their diet, and we can’t account for that.”
From the study, scientists suggest that people should keep dietary cholesterol intake low by reducing cholesterol-rich foods such as eggs and red meat in their diet.
Zhong said, “But don’t completely banish eggs and other cholesterol-rich foods from meals, because eggs and red meat are good sources of important nutrients such as essential amino acids, iron, and choline. Instead, choose egg whites instead of whole eggs or eat whole eggs in moderation.”
Allen said, “We want to remind people there is cholesterol in eggs, specifically yolks, and this has a harmful effect. Eat them in moderation.”
The study will be published on March 15 in JAMA.