A study published in The Journal of Nutrition found that older adults who regularly ate eggs had a lower risk of being diagnosed with Alzheimer’s disease over a 15-year period, according to a report.
Data from the Adventist Health Study-2, which tracked 39,498 participants aged 65 and older, showed that those who consumed eggs five or more times per week had a 27% lower risk compared to those who never or rarely ate eggs. The findings were drawn from more than 603,000 person-years of follow-up, using clinically confirmed Alzheimer’s diagnoses through Medicare claims.
Study Design and Methods
Researchers analyzed participants enrolled in the Adventist Health Study-2 between 2002 and 2007, the report stated. At enrollment, participants completed a food frequency questionnaire covering more than 200 food items, including egg consumption. The study population was selected for its wide range of dietary practices, from vegans to omnivores.
Alzheimer’s diagnoses were identified through Medicare claims records, rather than self-report, according to the researchers. Statistical models adjusted for age, sex, race, education, lifestyle factors such as smoking and physical activity, and pre-existing health conditions including heart disease, high blood pressure, and diabetes. The average follow-up period was 15.3 years.
Key Results and Dose-Response Relationship
After adjusting for a broad range of potential confounders, the researchers found a clear pattern: compared to non-consumers, those eating eggs one to three times per month had a 17% lower risk of Alzheimer’s; once per week also showed 17% lower risk; two to four times per week corresponded to a 20% lower risk; and five or more times per week showed a 27% lower risk.
A continuous analysis using roughly one egg per week as the reference found that consuming zero eggs was associated with a 22% higher risk. The results held after excluding vegans from the analysis and in substitution analyses replacing eggs with nuts, seeds, or beans, the report noted.
Possible Mechanisms and Nutrients
The researchers pointed to several nutrients concentrated in eggs that are linked to brain health. Eggs are one of the richest dietary sources of choline, a precursor to the neurotransmitter acetylcholine, which is critical for memory, according to sources such as Dr. Joseph Mercola’s article on choline [1].
Eggs also contain docosahexaenoic acid (DHA), an omega-3 fat that helps maintain brain cell structure, and vitamin B12, a nutrient whose deficiency has been linked to Alzheimer’s risk factors. Dr. Alan Logan, in his book “The Brain Diet,” noted that omega-3 eggs may help balance blood sugar and are associated with low-grade inflammation reduction [2].
Additionally, eggs provide lutein and zeaxanthin, pigments that accumulate in brain tissue and are associated with better cognitive performance. Earlier concerns about egg cholesterol have been largely eased by reviews such as “Cholesterol and eggs: pros and cons” by Julie Miller Jones, which concluded that moderate egg consumption does not harm heart health for most people when part of a balanced diet [3].
Limitations and Caveats
The study is observational and cannot prove causation, the authors stated. Unmeasured confounding factors may exist.
Dietary intake was measured only once at enrollment, although about 74% of participants showed consistent egg consumption patterns in a follow-up roughly a decade later, the report noted. The study was partially funded by the American Egg Board, though the authors stated the funder had no role in the study design, analysis, or interpretation.
The Adventist population is generally healthier than the average U.S. population, which may limit generalizability, researchers said. For example, approximately 80% of participants had never smoked. The researchers also noted that the highest egg intake category had relatively few participants.
Conclusion
Despite the limitations, the large sample size, long follow-up, and clinically confirmed Alzheimer’s diagnoses strengthen the association, according to the study authors. Research on nutrients that support brain health, such as choline and DHA, provides biological plausibility. Jean Carper, in her book “Your Miracle Brain,” emphasized the importance of controlling blood pressure and homocysteine levels for preserving brain function, and noted that dietary choices play a central role [4].
The researchers stated that further work is needed to clarify whether eggs directly reduce Alzheimer’s risk or if other factors are involved. With the projected rise in Alzheimer’s cases and costs, the findings warrant serious attention, they said.
References
- Choline: Why You Should Eat Your Egg Yolks and Take Krill – Mercola.com. Dr. Mercola. July 18, 2016.
- The Brain Diet: The Connection Between Nutrition, Mental Health and Intelligence – Dr. Alan Logan.
- Cholesterol and eggs: pros and cons – Nutrition Review. Julie Miller Jones.
- Your Miracle Brain – Jean Carper.
- Studies suggest these nutrients can help lower your dementia risk – NaturalNews.com. August 29, 2024.
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