Share on PinterestEating eggs regularly is linked to less buildup of toxic proteins in brain, according to a study on human brains. Image credit: Ingrid Bertens/Stocksy
- A study finds that eating eggs is associated with a reduced risk of developing Alzheimer’s disease.
- Using brain autopsies, the scientists also showed that those who ate eggs more regularly had less protein buildup in the brain associated with Alzheimer’s.
- The researchers conclude that this link may be due to eggs’ choline and omega-3 content.
Eggs have been a dietary staple since before humans evolved to be humans. Although they are packed with nutrients, relatively cost-effective, and easy to source, they have been the subject of much controversy in the health and wellness domain over the years.
A study whose results appear in The Journal of Nutrition, however, may help reestablish their good reputation.
According to the authors, eating one egg per week was associated with a 47% reduction in Alzheimer’s risk compared with eating eggs less than once each month.
They also showed that those eating eggs had a reduced buildup of the toxic proteins associated with Alzheimer’s.
Before we get into the details, we should mention that some of the authors received funding from the Egg Nutrition Center, “the science and nutrition education division of the American Egg Board.”
The trouble with eggs: Are they good or bad for health?
Are eggs good for you or bad for you? One hundred years ago, and for thousands of years before that, eggs were considered essential. Nutrient-dense and rich in protein and micronutrients, eggs were a staple throughout the world.
Then, a few decades ago, scientists found that high levels of cholesterol in the blood were a risk factor for heart disease, so high-cholesterol eggs were pushed to the naughty corner.
However, as nutrition science progressed, it became clear that dietary cholesterol did not significantly impact blood levels of cholesterol.
Thanks to this new understanding, and a healthy dose of research funding from the Egg Nutrition Center, eggs were edged slowly back into play.
Their saturated fat content, though, is still a concern, so eggs are still partially sidelined. Still, they are likely much healthier than many of the low-fat, highly processed snacks that have replaced eggs in modern kitchens. In fact, eggs contain all essential trace elements.
Today, most nutritionists and associated experts have a relatively neutral view of eggs. In general, the advice is that they can form a part of a healthy, well-balanced diet, but at the same time, eating multiple eggs per day could be unhealthy.
Eggs and Alzheimer’s: What is the link?
Alzheimer’s is the most common form of dementia, and despite decades of research, there is no cure, and treatments that can slow the disease are severely lacking.
For that reason, understanding the lifestyle factors associated with increased risk is essential. In this vein, many scientists are focusing on dietary influences.
Previous research has shown that choline is important for cognitive function. It has also identified a potential link between moderate choline intake and a reduced risk of dementia. As the authors of the latest study explain, eggs are the “top food source” of choline, so they are worth investigating.
Choline has many important functions; for instance, it is a precursor to the neurotransmitter acetylcholine, plays a pivotal role in cell membranes, and has neuroprotective powers.
Also, as the authors explain, “choline modulates the expression of key genes related to memory, learning, and cognitive functions via epigenetic mechanisms.”
Although our body can synthesise choline, it cannot synthesize enough to meet all the body’s needs, so some must be taken in with our diet.
Aside from choline, eggs contain essential omega-3 fatty acids, which support brain health as we age. Worryingly, studies show that the majority of adults in the United States do not consume enough of these essential fatty acids.
These facts led the authors of the new study to investigate links between egg consumption and Alzheimer’s risk.
Reduced risk and less protein buildup
The recent study included data from 1,024 older adults with an average age of 81.4. All participants lived in retirement communities and residential facilities in Illinois.
They attended yearly checkups and completed food frequency questionnaires, and the researchers followed them for an average of 6.7 years.
During this time, a little over one-quarter of them developed Alzheimer’s disease.
After analysis, the scientists found that individuals who consumed at least one egg per week had a 47% reduced risk of developing Alzheimer’s during follow-up compared with those eating one egg per month or fewer.
In the second part of their study, they looked at the post-mortem brains of 578 participants. They found that those who ate one or more eggs each week were more likely to have less Alzheimer’s-associated protein buildup.
Choline and omega-3 synergy
Overall, the authors suggest that consuming at least one egg per week may help reduce the risk of Alzheimer’s. They explain that the choline and omega-3s in eggs might have a “synergistic” effect, whereby they join forces to protect brain health during aging.
Medical News Today spoke to Christopher U. Missling, PhD, president and CEO of Anavex Life Sciences, who was not involved in the study. Missling explained that:
“About 39–40% of the protective effect was explained by higher dietary choline intake. Egg yolks also contain omega-3 fatty acids, which have known neuroprotective properties. The combination of choline and omega-3s may be particularly beneficial for brain health.”
The study authors also point to previous research demonstrating that people with Alzheimer’s are more likely to be deficient in omega-3s and choline.
Overall, the scientists conclude that, “once replicated in other prospective cohorts and confirmed by clinical trials, these findings may have important public health implications for reducing the population’s risk of [Alzheimer’s].”
If the results are replicated, this could be a very useful, low-cost intervention. MNT also spokle with Maddie Gallivan, RD, a registered dietitian who was likewise not involved in the recent study.
“Eggs are often a go-to food for older adults, as they’re soft in texture, which can be helpful for those with dentures, quick to prepare, and packed with key nutrients,” Gallivan explained. “So it’s great to see a study focussing on how they may support cognitive health in later life.”
Limitations and future research
However, the study does have certain limitations. For instance, they only had a relatively short follow-up — just 6.7 years. This, as the authors explain, increases the risk of reverse causality.
“The study population consisted of older adults from the Rush Memory and Aging Project, a specific U.S.-based cohort,” Missling told MNT. “The findings may not generalize to younger populations or those from different cultural or dietary backgrounds.”
He also reminded us that “dietary intake was assessed through self-reported food frequency questionnaires, which are subject to recall bias and inaccuracies.” So, participants may not have accurately reported or remembered their egg consumption.
“It’s important to remember that no single food acts in isolation,” Gallivan told us, “and it’s our overall dietary pattern that really counts. A varied, nutrient-dense diet rich in whole foods is key to supporting brain health and reducing dementia risk.”
For now, if you like eggs, enjoy them. They may reduce your dementia risk, but if not, they will certainly provide you with a good dose of protein and a healthy range of micronutrients.
