New research suggests that following a Mediterranean-style diet could help lower the risk of dementia and slow cognitive decline, even for people with strong genetic predispositions. Dementia arises from a mix of genetic, lifestyle, and environmental factors, and one of the most significant genetic risks comes from the APOE4 variant. Carrying one copy of APOE4 triples the risk of Alzheimer’s disease, while two copies increase the risk up to twelvefold.
The study, published in Nature Medicine, analyzed data from more than 5,600 participants over three decades, tracking long-term diet, blood samples, genetic information, and cognitive performance. People who adhered closely to a Mediterranean-style diet—rich in vegetables, fruits, nuts, and whole grains, and low in red and processed meats—showed a lower likelihood of developing dementia and experienced slower cognitive decline. The benefits were especially pronounced in individuals with two copies of the APOE4 gene.
Dietary Interventions Could Influence Brain Health
The research also examined blood metabolites, small molecules that reflect how the body processes food and regulates functions, revealing potential metabolic pathways through which diet could affect cognitive health. While the APOE4 variant disrupts fat transport in the brain and may increase amyloid plaque buildup, adherence to a Mediterranean diet appears to mitigate some of these effects.
Although the study’s participants were mostly of European ancestry, the findings highlight the potential for dietary strategies to complement genetic and metabolic assessments in dementia prevention. Researchers suggest that future work could focus on targeting specific metabolites to develop personalized dietary interventions for high-risk individuals.
Yuxi Liu, one of the study’s authors from a Harvard University hospital, emphasized: “These findings suggest that dietary strategies, specifically the Mediterranean diet, could help reduce the risk of cognitive decline and stave off dementia by broadly influencing key metabolic pathways.”
