Healthy dietary patterns are linked to a lower risk of cognitive decline

24 February 2026

A recent study published in JAMA Neurology reported that healthy dietary patterns are linked to a lower risk of subjective cognitive decline (SCD), an early sign of cognitive problems. The research aimed to address discrepancies in earlier studies on the same topic by examining six established healthy diets: the Dietary Approaches to Stop Hypertension (DASH), the Healthful Plant-Based Diet Index (hPDI), the Planetary Health Diet Index (PHDI), and two empirical dietary indices for hyperinsulinaemia (rEDIH) and inflammation (rEDIP).

The study received data from around 290,000 female nurses and male health professionals, who filled in questionnaires over many years covering diet, lifestyle, socioeconomic background, and medical history. Cognitive outcomes were measured by the participants’ reports of changes in memory and thinking and tests over the telephone in older adults.

All six dietary patterns were associated with lower risks of SCD. The DASH diet showed the strongest relationship and was also linked with better performance in global cognition, verbal fluency, and working memory.

The results also showed that higher consumption of vegetables and fish, with lower intake of red and processed meats, was associated with healthier cognitive outcomes. In contrast, fried potatoes, sugary drinks, sweets, and processed meats were linked to poorer cognition.

These findings show that healthy dietary habits should be part of long-term strategies to maintain brain health and reduce dementia risk.