Diets based on the Mediterranean region may contribute to a decrease in dementia risk.

In a groundbreaking long-term study, researchers have found that adhering to a Mediterranean diet may offer significant protection against memory and thinking skills decline, particularly for individuals at higher genetic risk.

Led by Yuxi Liu, the study focused on the Mediterranean diet and its potential role in shaping brain outcomes, even for those with the strongest inherited risks. The research involved 420 individuals carrying two copies of the APOE4 gene variant, a strong risk marker for Alzheimer's disease.

The findings suggest that diet may influence how genes behave by changing the chemical environment in the body. Those who followed the Mediterranean diet rich in omega-3 fatty acids, fiber, and leafy greens saw a reduction in dementia risk by 35%.

The diet appears to be linked to a healthier mix of metabolites in the blood, even for those carrying genes that usually spell trouble for the brain. People who ate a Mediterranean-style diet tended to have fewer harmful compounds associated with inflammation and poor clearance of brain waste products, and higher levels of antioxidant byproducts, such as those related to caffeine.

Among those with the highest genetic risk, those who stuck to this eating pattern showed fewer signs of memory decline over time. No single habit can erase genetic risk, but the right choices may tilt the odds in a better direction and help preserve memory longer.

The study followed thousands of men and women over several decades, looking at their eating patterns, genetic profiles, and blood chemistry. By adding metabolite information to standard health data, researchers were able to make more accurate predictions of who would develop dementia, compared to relying on family history alone.

This hints at a future where doctors may combine genetic and chemical clues to give more personalised advice. The study cannot prove cause and effect because it is based on observation, not direct intervention. However, the strength of the findings and the size of the study make it clear that genetics do not tell the whole story.

Other protective compounds tied to this diet included healthy fats and plant-based molecules that help fight stress in the body. Researchers also studied genes involved in brain tissue repair to see how they might interact with diet and metabolism.

Focusing on a balanced diet rich in plants, healthy fats, and whole foods remains one of the most practical steps for supporting brain health. The Mediterranean diet includes fruits, vegetables, nuts, whole grains, olive oil, and moderate amounts of fish and poultry, while limiting processed foods and red meat.