Eating healthy good for the brain

Diets such as the Dietary Approaches to Stop Hypertension (DASH) and those with lower hyperinsulinemia and inflammation potential have beneficial effects on cognitive health, as shown in a study.

The study included participants from the Nurses’ Health Study (NHS, 1986-2014), NHSII (1991-2017), and the Health Professionals Follow-Up Study (HPFS, 1986-2012). A total of 159,347 participants (mean age 44.3 years, 82.6 percent female) with available data on diet and cognitive function were included in the analyses.

Dietary patterns were assessed using the following: the Alternate Healthy Eating Index 2010 (AHEI-2010), DASH diet score, the Healthful Plant-Based Diet Index (hPDI), the Planetary Health Diet Index (PHDI), and the reversed empirical dietary indices for hyperinsulinemia (rEDIH) and inflammatory pattern (rEDIP). Subjective cognitive decline was evaluated using seven questions on perceived cognitive changes. Cognitive function was objectively measured via telephone in the NHS.

Higher adherence to all six dietary patterns was associated with a lower risk of subjective cognitive decline. The beneficial effect was most pronounced with the DASH diet (90th vs 10th percentile of adherence: risk ratio [RR], 0.59, 95 percent CI, 0.57–0.62). This was followed by the hPDI (RR, 0.76, 95 percent CI, 0.65–0.85), rEDIH (RR, 0.76, 95 percent CI, 0.73–0.80), PHDI (RR, 0.80, 95 percent CI, 0.75–0.86), AHEI-2010 (RR, 0.84, 95 percent CI, 0.80–0.89), and rEDIP (RR, 0.89, 95 percent CI, 0.85–0.93). The strongest association was observed between higher DASH diet score at ages 45–54 years and subjective cognitive decline.

Higher adherence to the DASH diet also showed the strongest protective association with objectively measured global cognition (90th vs 10th percentile of adherence: mean z score difference, 0.05, 95 percent CI, 0.02–0.09).

Among key food groups, higher vegetable and fish intake and lower red and processed meats intake were associated with better cognitive function.