Study: More than 1 egg a day could increase risk for heart disease

Scrambled, poached or over easy: No matter how you take your eggs, there’s not really a sunny side to a new study that links egg consumption with a higher risk of cardiovascular disease. 

This news might be hard to swallow for some egg lovers, considering the fact that the 2015-2020 Dietary Guidelines for Americans actually encourages the consumption of eggs as part of a healthy eating pattern.

The study, published in the Journal of the American Medical Association by researchers at Northwestern University, found that consuming 300 milligrams of dietary cholesterol per day had a significant relationship to an individual’s risk for cardiovascular disease. 

The researchers calculated that those who ate 300 milligrams of cholesterol daily — about 1 ½ eggs — were 17 percent more likely to develop heart disease than those who didn't eat eggs.

“Each additional half an egg consumed per day was significantly associated with higher risk of incident CVD and all-cause mortality,” the study says.

One large egg can contain up to 186 milligrams of dietary cholesterol in the yolk alone. 

Researchers who conducted the study explained that when it comes to a normal human diet, cholesterol is quite common, with eggs being a major source of dietary cholesterol. Egg yolks, specifically, are one of the richest sources. 

According to the study, the average adult consumes about 300 milligrams of cholesterol per day and eats about three to four eggs every week. 

Researchers at Northwestern University's Feinberg School of Medicine and elsewhere pooled results from six previous studies, analyzing data on almost 30,000 U.S. adults who self-reported daily food intake. Participants were followed for roughly 17 years, on average.

The researchers based their conclusions on what participants said they ate at the start of each study. They took into account high blood pressure, smoking, obesity and other traits that could contribute to heart problems. Risks were found with eggs and cholesterol in general; a separate analysis was not done for every cholesterol-rich food.

Dr. Bruce Lee of Johns Hopkins University said nutrition studies are often weak because they rely on people remembering what they ate.

"We know that dietary recall can be terrible," said Lee. The new study offers only observational data but doesn't show that eggs and cholesterol caused heart disease and deaths, said Lee, who wasn't involved in the research.

Senior author Norrina Allen, a preventive medicine specialist, noted that the study lacks information on whether participants ate eggs hard-boiled, poached, fried, or scrambled in butter, which she said could affect health risks.

Some people think '"I can eat as many eggs as I want'" but the results suggest moderation is a better approach, she said.

The Associated Press contributed to this story.