Harvard study finds DASH diet outperforms Mediterranean for brain health

Researchers at Harvard T.H. Chan School of Public Health compared six popular eating patterns using data from 159,347 participants followed for several decades. The analysis, published in JAMA Neurology, showed that strict adherence to the DASH diet (Dietary Approaches to Stop Hypertension) was associated with a 41% lower risk of cognitive decline compared with low adherence, making it the most protective diet for brain health.

The DASH diet, originally designed to lower blood pressure, emphasizes fruits, vegetables, whole grains, low‑fat dairy, fish, lean meat and nuts while limiting sodium, saturated fat, processed meat, added sugars and alcohol. It ranked ahead of plant‑based, low‑insulin, planetary‑health, Mediterranean and anti‑inflammatory diets, all of which also showed modest cognitive benefits. The authors note the findings are observational and do not prove causality, but align with other research suggesting that nutrition beneficial for the cardiovascular system also supports brain function.