Bolstering the many research studies finding that the Mediterranean diet is good for the heart and the brain, a study published today in Nature Medicine reports that the diet can help protect cognitive function in people with a genetic risk for Alzheimer’s disease. Yuxi Liu, Ph.D., of Harvard Medical School, and colleagues made use of genetic, metabolic, and dietary data from 4,215 women enrolled in the long-running Nurses’ Health Study (NHS) and 1,490 men enrolled in the similarly designed Health Professionals Follow-Up Study (HPFS). Participants in both studies provided blood samples at enrollment and completed biennial questionnaires on their lifestyle and health. A subgroup of 1,037 women in the NHS also completed a series of phone-based cognitive tests. During the follow-up period (1989 to 2023 for the NHS and 1993 to 2023 for the HPFS), 485 NHS participants and 121 HPFS participants developed dementia. Liu and colleagues found that individuals who more closely adhered to a Mediterranean-style diet had a reduced risk of developing dementia along with higher age-adjusted scores on the cognitive tests. Individuals with two copies of the apolipoprotein E4 (APOE4) gene variant—a strong predictor of Alzheimer’s—had around a 35% reduced risk of developing dementia, whereas individuals with one or zero copies of the variant had a more modest 5% reduced risk. The researchers next integrated metabolomic data from the participants and found that individuals with two copies of APOE4 and dementia had a distinct metabolite profile relative to other individuals with dementia. Further, many of the metabolites associated with dementia risk in double APOE4 carriers were in metabolic pathways that are influenced by the Mediterranean diet. “ADRD [Alzheimer’s disease–related dementia] has long been considered a metabolic disease, largely due to the central role of APOE4 in lipid transport and metabolism,” the researchers wrote. “Our study not only identifies mechanistic insights, but also proposes actionable prevention strategies targeting these pathways. This has important implications for public health messaging, highlighting the overall benefit of adhering to the [Mediterranean diet] for ADRD prevention, as well as the potential for targeted interventions in genetically vulnerable populations.” (SOURCE: APA Psychiatrc News Alert)