While the cause of Alzheimer’s disease is not known, genetics plays a role. A variant of the apolipoprotein E (APOE) gene, called APOE4, is a confirmed risk gene. Having one copy (from one parent) increases someone’s risk, and having two raises it even more.
A study published online Aug. 25, 2025, by Nature Medicine found that it may be possible to counter some of the effects of APOE4 by following a Mediterranean diet. Previous research has linked this eating pattern to better cognitive function. For the current study, researchers analyzed medical data from long-term studies on 4,125 women (followed from 1989 to 2023) and 1,490 men (1993 to 2023), focusing on genetic data, dietary patterns, and certain metabolites (molecules created during normal body function) linked to dementia risk.
The researchers found that study participants who adhered most closely to a Mediterranean-style diet had a lower risk of Alzheimer’s disease and better cognitive function. The effect was most pronounced among those with two copies of APOE4. The study also suggested that the effect is likely due to the impact of the diet on specific metabolites, thus reinforcing the validity of the findings.
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