Eating one egg per day may help lower risk of heart disease, study suggests

FILE IMAGE - Eggs in a carton sit on a kitchen counter in Lafayette, California, in a file image dated Jan. 15, 2021. (Photo by Smith Collection/Gado/Getty Images)

Eating up to one egg per day may help lower the risk of developing heart disease, according to a new study. 

The study, published last week in the peer-reviewed journal eLife, found that moderate egg consumption can increase the amount of heart-healthy metabolites in the blood — which may partially explain the protective effect of moderate egg consumption on cardiovascular disease, according to the researchers. 

Eggs are loaded with a variety of nutrients, while also containing a high level of dietary cholesterol — leading to conflicting evidence and confusion as to whether eggs are, in fact, healthy. 

A 2018 study published in the journal Heart found that those who ate about one egg per day had a substantially lower risk of heart disease and stroke, compared to those who ate eggs less frequently. That study included about 500,000 adults in China. 

The authors of the newest research carried out a population-based study, also in China, to better understand how eating eggs affects markers of cardiovascular health in the blood.

"Few studies have looked at the role that plasma cholesterol metabolism plays in the association between egg consumption and the risk of cardiovascular diseases, so we wanted to help address this gap," lead author Lang Pan, MSc, from the Department of Epidemiology and Biostatistics, Peking University, in Beijing, China, said in a statement.

Pan and the research team chose 4,778 participants from the China Kadoorie Biobank. Among those people, 3,401 had a cardiovascular disease and 1,377 did not. 

The study looked at metabolites — or a substance made or used when the body breaks down things like food and fat tissue. This process, known as the body’s metabolism, makes energy and the materials needed for growth, reproduction and maintaining health, according to the National Institutes of Health

The study measured 225 metabolites in plasma samples taken from the participants’ blood. Of these metabolites, the team identified 24 that were associated with egg consumption.

The analysis found that individuals who reported eating a moderate amount of eggs (up to one per day) had higher levels of a protein in their blood called apolipoprotein A1, which is a building block of high-density lipoprotein (HDL), also sometimes referred to as the "good" cholesterol. These individuals particularly had more large HDL molecules in their blood, which help clear cholesterol from the blood vessels and protect against blockages that can lead to heart attacks and stroke, according to the study.

The team also identified 14 metabolites that are linked to heart disease and found that those who ate fewer eggs had lower levels of beneficial metabolites and higher levels of harmful ones in their blood, compared to those who ate eggs more regularly, the study said.

"Together, our results provide a potential explanation for how eating a moderate amount of eggs can help protect against heart disease," study author Canqing Yu, associate professor at the Department of Epidemiology and Biostatistics at Peking University, said in the statement. 

The study was funded by the National Natural Science Foundation of China, the Kadoorie Charitable Foundation in Hong Kong, the National Key R&D Program of China, and the Chinese Ministry of Science and Technology.

The researchers noted how more studies are needed to verify the roles that lipid metabolites play in the link between eating eggs and heart disease risk. 

What do the US dietary guidelines say about eggs?

The current U.S. dietary guidelines recommend eggs as part of an overall healthy diet that reflects one’s personal preferences, cultural traditions and budgetary considerations. 

The main elements that make up a healthy diet include vegetables and fruits of all types, whole grains, and dairy, including fat-free or low-fat milk, yogurt, and cheese or alternative versions. Protein foods are also included, such as lean meats, poultry, eggs, seafood, beans, peas, lentils, nuts and soy products, and various oils. 

The American Heart Association suggests one egg — or two egg whites — per day for people who eat them, as part of a healthy diet.

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This story was reported from Cincinnati.