Which diets are associated with better cognitive function

The participants’ diets were assessed using food frequency questionnaires, food diaries, and dietary histories, after which the data were standardized to measure the degree of adherence to seven popular healthy eating patterns — among them were the Mediterranean diet in various forms, DASH (a diet for controlling blood pressure), MIND (a special diet to slow down neurodegenerative processes), as well as healthy eating indices and the EAT‑Lancet model.

The results showed that the relationship between diet and cognitive abilities depends on how the data are viewed — in the moment or in dynamics. In a cross‑sectional analysis, when diet and cognitive functions were assessed simultaneously, a higher adherence to the continuous version of the Mediterranean diet correlated with better indicators of overall cognitive status. In addition, strict adherence to the Mediterranean diet and the DASH diet was associated with higher efficiency of executive functions, i.e., the ability to plan, switch between tasks, and control impulsive reactions.

However, these benefits do not necessarily mean long‑term brain protection. When scientists tracked the participants over time, the picture changed: only the MIND diet, studied in three American cohorts, demonstrated a link to the preservation of executive functions in the long term. No significant improvements in dynamics were found for the other diets.

One of the authors of the study, Lin Steffen from the University of Minnesota, notes that these data are consistent with the results of a large randomized clinical trial, which found no significant differences in cognitive performance between those who followed the MIND diet and those who were on a control diet.

The key conclusion of the study is that the quality of nutrition likely supports cognitive health, but is unlikely to have a noticeable long-term effect on its own. Most likely, a combination of several factors is important for slowing age-related decline in cognitive functions — primarily a balanced diet and regular physical activity.

Given that today about 57 million people worldwide live with dementia, and 10 million new cases are recorded each year, such data are especially important for developing comprehensive prevention measures.