A new study suggests that following a Mediterranean-style diet can reduce the risk of dementia and slow cognitive decline, even in people with strong genetic predispositions. The diet, which emphasizes vegetables, fruits, nuts, whole grains, and limits red and processed meats, showed the strongest benefits for individuals carrying two copies of the APOE4 gene variant—a major risk factor for Alzheimer’s disease. People with one copy of APOE4 triple their risk, while those with two copies are up to 12 times more likely to develop Alzheimer’s.
Research Highlights and Implications
The study, published in Nature Medicine, analyzed data from over 5,700 participants over three decades, tracking dietary habits, blood samples, genetic profiles, and cognitive performance. Researchers found that even those at high genetic risk experienced slower cognitive decline when adhering to a Mediterranean diet.
“The findings suggest that dietary strategies, specifically the Mediterranean diet, could broadly influence metabolic pathways to help reduce cognitive decline and stave off dementia,” said Yuxi Liu, a Harvard University researcher and co-author. The team also examined blood metabolites, the small molecules reflecting how the body processes food, to better understand how diet interacts with genetics.
While carrying APOE4 increases Alzheimer’s risk, it does not guarantee disease development. The study emphasizes that lifestyle interventions, such as diet, can partially counteract genetic vulnerabilities. However, researchers caution that the cohort was largely of European ancestry and well-educated, highlighting the need for further studies in more diverse populations.
“Future research may explore targeting specific metabolites through diet or other interventions to provide a more personalized approach to reducing dementia risk,” Liu added, suggesting a path toward individualized prevention strategies.
