Eating Eggs Weekly Linked to Lower Alzheimer’s Risk, Study Shows

Eggs are a staple in many American households and are often lauded for being a good source of protein. However, a study has found that eating one egg per week may also offer protective benefits for brain health.

What the Research Says

The prospective cohort study, published in The Journal of Nutrition, found that consuming one or more eggs per week was associated with a 47% reduced risk of Alzheimer’s dementia compared with those who rarely ate eggs.

The study included 1,024 older adult participants living in the Chicago area who self-reported their egg intake and underwent regular health checkups over an average of 6.7 years. During this period, 280 participants (or 27.3%) were clinically diagnosed with Alzheimer’s dementia.

The researchers also analyzed brain autopsies from 578 deceased participants and found that egg consumption was associated with less build-up in the brain of a protein linked to Alzheimer’s.

“Earlier studies reported some cognitive improvements linked to regular egg consumption. However, this is the first to show that eating more than one egg per week is significantly associated with a lower risk of both Alzheimer’s dementia and brain pathology associated with the disease,” said Lina Begdache, PhD, RDN, CDN, CNS-S, FAND, a dietitian-nutritionist and associate professor of Health and Wellness Studies at Binghamton University, State University of New York.

It’s important to note that some authors received funding from the Egg Nutrition Center for this research.

Which Nutrients May Have a Protective Effect?

The authors conducted a mediation analysis to determine how much of this benefit might come from choline, an essential nutrient found abundantly in eggs.

“Choline is not the only nutrient in eggs that could potentially support brain health,” said Mei Chung, PhD, one of the study authors and an associate professor in nutrition science at Tufts University. “In addition to choline, eggs are also rich in Omega-3, lutein, vitamin B12, folate, and protein.”

Their mediation analysis showed that about 39% of the potential benefit from eating eggs on the risk of Alzheimer’s can be attributed to choline, suggesting that the other nutrients in eggs may also play important roles.

What Is the Link Between Choline and Alzheimer’s?

The egg study, published last year, was secondary research to a study of choline and Alzheimer’s conducted on the same cohort. The choline study was conducted first but was only recently published in the Journal of Nutrition.

In this study, researchers analyzed the association between different intake levels of choline and the risk of Alzheimer’s. They also conducted an analysis to look at the longitudinal intake level of choline across years and the risk of Alzheimer’s.

They found that the association between choline intake and Alzheimer’s risk was non-linear, and that approximately 350 mg of choline per day was associated with the lowest risk of clinical diagnosis of Alzheimer’s in older adults. That’s equivalent to about two or three large eggs per day.

What About Cholesterol?

While eggs are generally healthy, they have sometimes been considered controversial because of their cholesterol content.

Because they are a source of cholesterol, Begdache said they could raise LDL cholesterol (the bad cholesterol) in individuals with already elevated blood lipids. However, a recent study published in The American Journal of Clinical Nutrition found that eggs may actually lower LDL cholesterol.

“High blood cholesterol has been linked to a decline in cognitive functions, increasing the risk of Alzheimer’s disease,” she said. “Therefore, there should be a thoughtful discussion with healthcare professionals before increasing egg consumption in individuals with high blood cholesterol.”

Is One Egg Really Enough?

While the researchers do not offer an official recommendation of how many eggs to consume, Begdache said the emphasis was on general regular consumption, which builds these nutrients in the brain.

“Including eggs in a balanced diet may be an easy, cost-effective step toward promoting long-term cognitive health,” she said.