Mediterranean Diet May Reduce Dementia Risk, Especially for Those genetically Predisposed: Study
A new study led by investigators from Mass general Brigham, Harvard T.H. Chan School of Public Health, and the Broad Institute of MIT and Harvard suggests that a Mediterranean-style diet may help reduce dementia risk. The study, published in Nature Medicine, found that peopel at the highest genetic risk for Alzheimer’s disease benefited more from following a Mediterranean-style diet, showing a greater reduction in dementia risk compared to those at lower genetic risk.
“One reason we wanted to study the Mediterranean diet is as it is indeed the only dietary pattern that has been causally linked to cognitive benefits in a randomized trial,” saeid study frist author Yuxi Liu, Ph.D., a research fellow in the Department of Medicine at Brigham and Women’s Hospital and a postdoctoral fellow at the Harvard Chan School and Broad.”We wanted to see whether this benefit might be different in people with varying genetic backgrounds, and to examine the role of blood metabolites, the small molecules that reflect how the body processes food and carries out normal functions.”
Over the last few decades, researchers have learned more about the genetic and metabolic basis of Alzheimer’s disease and related dementias. These are among the most common causes of cognitive decline in older adults. Alzheimer’s disease is known to have a strong genetic component, with heritability estimated at up to 80%.
One gene in particular, apolipoprotein E (APOE), has emerged as the strongest genetic risk factor for sporadic alzheimer’s disease-the more common type develops later in life and is not directly inherited.
Mediterranean diet may mitigate genetic risk of dementia
A new study published in Nature Medicine reveals a complex interplay between genetic predisposition, plasma metabolome, and adherence to a Mediterranean diet in influencing dementia risk and cognitive function. Researchers found that while genetic factors significantly contribute to dementia risk, a Mediterranean diet can substantially mitigate these effects.
The study analyzed data from a large cohort, examining genetic profiles, blood metabolomes (a thorough analysis of metabolites in the blood), and dietary habits. Results indicated that individuals with a higher genetic risk for dementia experienced a reduced risk when they closely followed a Mediterranean diet rich in fruits, vegetables, whole grains, fish, and healthy fats.
Specifically, the researchers identified several metabolites in the plasma that mediated the protective effects of the diet. These metabolites are associated with improved brain health and reduced inflammation. The study suggests that the Mediterranean diet alters the plasma metabolome in a way that counteracts the negative effects of genetic risk factors.
“Our findings highlight the potential for dietary interventions to modify the trajectory of dementia risk,even in individuals with a strong genetic predisposition,” says lead author Dr. [Name Redacted for Privacy]. “This is encouraging, as diet is a modifiable factor, offering a proactive approach to brain health.”
The research team emphasizes that this is not a one-size-fits-all solution. Genetic risk varies significantly between individuals, and the optimal dietary approach may differ accordingly. however, the study provides strong evidence supporting the broad benefits of a Mediterranean diet for cognitive health and dementia prevention.
More information: Interplay of genetic predisposition, plasma metabolome, and Mediterranean diet in dementia risk and cognitive function, Nature Medicine (2025). DOI: 10.1038/S41591-025-03891-5
Provided by Mass General hospital