An international group of scientists conducted a prospective population cohort study, the aim of which was to determine the relationship between strong adherence to the Mediterranean diet and the probability of cognitive impairment, as well as to assess the effect of racial risk factors and vascular on the probability of cognitive impairment.

During the implementation of this project, information was analyzed on the patients who participated in the study devoted to the study of the geographic and racial differences of stroke (REGARDS), which was carried out in 2003 -2007 for the reasons of geographic and racial differences in strokes. The current analysis did not include people with anamnestic stroke data, cognitive impairment at the time of inclusion in the study, and patients who had not completed questionnaires containing questions about physical activity and the nature of nutrition (Food Frequency Questionnaires - FFQ). Adherence to the Mediterranean diet (with a score of 0 to 9) has just been assessed by completing the FFQ questionnaire.

Cognitive status was assessed during the initial visit, then annually throughout the follow-up period, which lasted an average of 4.0 ± 1.5 years.

Cognitive impairment was detected in 1,248 (7%) of the 17,478 patients who met the inclusion criteria. Greater adherence to the Mediterranean diet led to a lower probability of cognitive impairment before (odds ratio 0.89, 95% confidence interval 0.79-1.00) and after correction of the data for potential interfering factors (odds ratio 0.87, 95% confidence interval 0.76-1.00), including demographic characteristics, influence of environmental factors, vascular factors, symptoms of depression and self-reported health status. There was no association between race (p = 0.2928) and adherence to a Mediterranean diet with cognitive status. At the same time, the researchers found a clear effect of diabetes mellitus (p = 0.0134) on the relationship between food intake and cognitive impairment. Strong adherence to the Mediterranean diet was associated with a lower likelihood of cognitive impairment in patients without diabetes (odds ratio 0.81; 95% CI 0.70-0.94; p = 0.0066), but not in people with diabetes (odds ratio 1.27; 95% CI 0.95-1.71; p = 0.1063).

Thus, this large-scale study has shown that strong adherence to the Mediterranean diet leads to a lower probability of cognitive impairment, whatever the potential interference factors.