Eating eggs regularly reduces Alzheimer’s disease risk

Researchers tracked nearly 40,000 older adults for 15 years and found that people who consumed eggs moderately developed Alzheimer’s disease less often than non-consumers.

Alzheimer’s Disease: Prevalence, Risk Factors, and Dietary Considerations

Alzheimer’s disease is a progressive neurodegenerative disorder marked by amyloid-β plaque accumulation, neurofibrillary tangles, and neuronal loss, resulting in cognitive decline and death. It is the sixth leading cause of death in the United States, with projected national management costs exceeding $600 billion annually by 2050.

Alzheimer’s disease etiology involves genetic, vascular, and environmental factors, notably diet. Due to the lack of curative treatments and limited pharmacological efficacy, prevention targeting modifiable risk factors is critical. Previous research indicated higher dementia mortality among vegetarians compared to non-vegetarians, despite reduced all-cause and other cause-specific mortalities with vegetarian diets.

Recent studies indicate egg consumption may be associated with Alzheimer’s disease risk, with moderate intake linked to a 10 % reduction in neurodegenerative mortality. However, most studies are limited by design flaws, inconsistent dietary assessment, lack of biomarker validation, and inadequate adjustment for confounders, underscoring the need for rigorous investigation.

Investigating the impact of egg consumption on Alzheimer’s disease risk

The current study exploited the Adventist Health Study-2 (AHS-2) cohort to examine the relationship between egg consumption and Alzheimer’s disease risk, drawing on extensive dietary and health data from over 96,000 participants. AHS-2 data were merged with Medicare claims and deidentified. For this analysis, only US participants aged 65 and older were included, with eligibility based on Medicare records.

A total of 39,498 participants met the eligibility criteria. Dietary intake was measured at baseline with a validated food frequency questionnaire covering over 200 items. Both frequency and quantity of egg intake were recorded, including visible and hidden sources. Egg intake categories ranged from never to five or more times per week, and intake was energy-adjusted.

To provide context for individual food intake, two substitution analyses were conducted to examine the replacement of eggs with nuts/seeds and legumes, which are nutrient-dense, commonly consumed plant-based protein sources in the cohort. These analyses examined how substituting eggs with alternative protein-rich foods might affect the risk of Alzheimer’s disease.

Moderate Egg Consumption Is Associated With Reduced Alzheimer’s Disease Risk

Significant baseline differences were observed across egg intake categories. The cohort had a mean age of 64 years and was 64 % female. Over 15.3 years of follow-up, 2,858 participants developed Alzheimer’s disease, with affected individuals more likely to have comorbidities and dietary patterns characterized by lower intake of eggs, meat, and fish and higher intake of fruits, grains, and nuts/seeds.

Multivariable-adjusted Cox proportional hazards models indicated that a higher frequency of egg consumption was independently associated with a lower risk of Alzheimer’s disease. After controlling for demographic factors, lifestyle variables, major food groups, and comorbidities, the hazard ratios (HRs) for Alzheimer’s disease, relative to never or rare egg intake, ranged from 0.83 for moderate intake (1–3 times per month or once per week) to 0.73 for frequent intake (5 or more times per week).

Any level of egg intake corresponded to a 17 %–27 % lower relative hazard of Alzheimer’s disease compared to no egg intake. This inverse relationship persisted after progressive adjustment for potential confounders.

Analysis of those consuming one or more eggs per day showed an HR of 0.74 compared to rare or no intake, but the small sample size limited statistical power. The study also noted that the highest intake category reflected frequency of consumption rather than precise daily egg counts. No significant interaction between sex or race/ethnicity and outcome was detected. The use of attained age as the time variable accounted for age-related risk.

Sensitivity analysis excluding vegans produced results consistent with the primary analysis, demonstrating a similar reduction in Alzheimer’s disease risk at higher egg intake frequencies.

Findings support possible brain-health role for eggs

The current study suggests that moderate egg consumption may be linked to a reduced risk of Alzheimer’s disease in older adults, adding to evidence that diet may play a role in brain health and supporting further investigation into the potential role of egg-derived nutrients in cognitive health.

The authors proposed several possible mechanisms that could explain this association, including nutrients found in eggs such as choline, DHA, lutein, zeaxanthin, phospholipids, and vitamin B12, although these mechanisms were not directly tested in the study.

Despite these key observations, this study has several limitations, including residual confounding that cannot be fully excluded due to the observational design and dietary intake measured only at baseline, which may not capture changes over time. Furthermore, reliance on Medicare data may lead to missing milder or undiagnosed Alzheimer’s cases. The authors also noted the possibility of reverse causation, in which preclinical Alzheimer’s disease could influence dietary habits before diagnosis, although they argued that dietary patterns in this cohort were generally stable over time. In addition, because death can occur before Alzheimer’s diagnosis in older adults, the reported hazard ratios should not be interpreted as direct measures of absolute disease risk.

Importantly, the study population consisted of a relatively health-conscious Seventh-day Adventist cohort with low rates of smoking and alcohol use and generally lower egg consumption than the broader US population, which may limit the generalizability of the findings.

Further research should explore diverse populations, long-term dietary patterns, and the effects of specific egg-derived nutrients. In addition, the underlying mechanisms of eggs' neuroprotective effects must be explained.

The analysis was supported by an investigator-initiated grant from the American Egg Board, although the authors stated that the funder had no role in study design, data analysis, interpretation, manuscript preparation, or publication decisions.

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Journal reference:

• Oh, J., Oda, K., Chiriac, G., Fraser, G. E., Sirirat, R., & Sabaté, J. (2026). Egg Intake and the Incidence of Alzheimer’s Disease in the Adventist Health Study-2 Cohort Linked with Medicare Data. The Journal of Nutrition. 101541. DOI: https://doi.org/10.1016/j.tjnut.2026.101541. https://www.sciencedirect.com/science/article/pii/S0022316626001902