Incredible, edible, scientifically credible?
A humble food, once thought to be bad for the heart, has now been linked to a reduced risk of Alzheimer’s disease.
For decades, eggs have been divisive, with protein proponents praising ova and cholesterol-conscious maligning them.
Now, new research in The Journal of Nutrition suggests that those who routinely eat eggs are less likely to be diagnosed with Alzheimer’s than those who never or rarely incorporate them into meals.
Further, the most consistent egg eaters, those who had five or more servings per week, showed a 27% lower risk.
“The key takeaway is that moderate egg consumption was consistently associated with a lower risk of Alzheimer’s disease,” study author Dr. Jisoo Oh told The Post.
She noted that these results support the evolving, overwhelmingly positive perception of eggs.
“Earlier concerns focused heavily on dietary cholesterol, but more recent research, including ours, suggests that moderate egg consumption is not harmful for most people and may even offer health benefits,” she said.
For years, health officials and medical groups recommended limiting egg consumption, concerned it could raise blood cholesterol and increase the risk of cardiovascular disease — the leading cause of death in the US.
However, research from last year found that eating two eggs a day as part of a high-cholesterol but low–saturated–fat diet can reduce LDL “bad” cholesterol and lower heart disease risk.
Oh and her team tracked nearly 40,000 older adults for more than 15 years. All participants were at least 65, enrolled in Medicare and had no diagnosis of Alzheimer’s at the start of the study.
Participants reported their egg intake in a detailed food questionnaire.
Based on the responses, researchers sorted them into five groups reflecting the frequency of egg consumption: never or rarely, one to three times per month, one time per week, two to four times per week and five or more times per week.
Experts say that healthy adults can safely consume up to seven eggs per week.
During the study window, 2,858 participants were diagnosed with Alzheimer’s. The degenerative disease, which affects millions of Americans, gradually destroys memory, thinking skills and the capacity to perform basic tasks.
Compared with those who never or rarely ate eggs, folks who ate them at least once a month and as often as once a week had a 17% lower risk of Alzheimer’s.
Those who ate eggs two to four times per week had a 20% lower risk, while the most frequent egg eaters, those who ate them five or more times per week, had a 27% lower risk.
“Importantly, this association remained after accounting for a wide range of factors, including overall diet, lifestyle and existing health conditions. While this does not prove causation, it suggests that eggs may play a beneficial role as part of a balanced dietary pattern that supports brain health,” said Oh.
To determine whether it was eggs specifically or protein-rich foods in general that lowered Alzheimer’s risk, Oh and her team ran substitution analysis to see what would happen if participants traded egg intake for equivalent portions of nuts, seeds or beans.
The egg-eating group still had a lower Alzheimer’s risk, indicating that the nutritional profile of eggs in particular supports sustained cognitive function.
“Eggs are a nutrient-dense food, providing choline, vitamin B12, lutein and omega-3 fatty acids, all of which are important for brain function,” said Oh.
Previous research has linked choline with a lower risk of cognitive impairment and reduced risk of dementia.
Meanwhile, omega-3 fatty acids are believed to preserve the integrity of brain cell membranes, facilitate neuronal communication, enhance blood flow to the brain, support the creation of new brain cells and reduce inflammation.
Furthermore, sufficient levels of B-12 are said to be critical for maintaining cognitive health. Last year, a study found that participants with lower B12 levels had “slower cognitive and visual processing speeds” on tests, which is linked to “subtle cognitive decline.”
However, Oh notes that, despite their robust nutritional profile, eggs are not a “magic food” and that their benefits are best understood within the context of an overall healthy diet.
Moreover, she shared that the study reflects whole-egg consumption, meaning both the egg yolk and egg white are eaten.
“This is important because many of the key nutrients linked to brain health, such as choline, vitamin B12, lutein and DHA, are concentrated in the yolk,” she explained.
Indeed, more than 90% of the choline in eggs comes from the yolk.
Oh maintains that while egg whites provide protein, they do not contain the same levels of neuroprotective nutrients as the yolk.
“So they may not offer the same potential benefits observed in this study,” she said.
While the study did not evaluate egg preparation, Oh said cooking methods matter.
“From a broader nutrition perspective, how eggs are prepared (e.g., boiled vs. fried with added fats) can influence overall health effects, so preparation still matters as part of the overall diet,” she advised.
Researchers acknowledge that there are limitations to the new study.
Dietary intake was measured only once during enrollment. While a follow-up comparison conducted 10 years into the study showed that 74% of participants were consistent in their egg consumption, this does not account for potential shifts over the course of the study.
The study was also funded in part by the American Egg Board, though the authors emphasized that this contribution had no bearing on the design, execution or interpretation of their research.
