A Mediterranean-style diet was linked to lower dementia risk, especially in people with high-risk Alzheimer’s genes. The greatest benefits were seen in those with two copies of the APOE4 gene -- the strongest genetic risk factor for the most common form of Alzheimer's disease -- showing diet may help offset genetic vulnerability. Researchers say food may influence key metabolic pathways that protect memory and cognitive function.

To explore how the Mediterranean diet may reduce dementia risk and influence blood metabolites linked to cognitive health, the team analyzed data from 4,215 women in the Nurses' Health Study, following participants from 1989 to 2023 (average age 57 at baseline). To validate their findings, the researchers analyzed similar data from 1,490 men in another observational study, followed from 1993 to 2023.

The team evaluated long-term dietary patterns using food frequency questionnaires and examined participants' blood samples for a broad range of metabolites. Genetic data were used to assess each participant's inherited risk for Alzheimer's disease. Participants were then followed over time for new cases of dementia. A subset of 1,037 women underwent regular telephone-based cognitive testing.

People following a more Mediterranean-style diet had a lower risk of developing dementia and showed slower cognitive decline. The protective effect in the high-risk group with two copies of the APOE4 gene variants suggests that diet may help offset genetic risk, according to the authors.

To download the full study, published in Nature Medicine, click here