The role of Mediterranean diet in the course of subjective cognitive decline in the elderly population of Greece: results from a prospective cohort study.

Very few data are available regarding the association of adherence to the Mediterranean Diet (MeDi) with Subjective Cognitive Decline (SCD) evolution over time. A cohort of 939 cognitively normal individuals reporting self-experienced, persistent cognitive decline not attributed to neurological, psychiatric or medical disorders from the Hellenic Epidemiological Longitudinal Investigation of Aging and Diet (HELIAD study) was followed-up for a mean period of 3·10 years. We defined our SCD score as the number of reported SCD domains (memory, language, visuoperceptual and executive), ranging from 0 to 4. Dietary intake at baseline was assessed through a food frequency questionnaire; adherence to the MeDi pattern was evaluated through the Mediterranean Diet Score (MDS) that ranged from 0 to 55, with higher values indicating greater adherence to the MeDi. The mean SCD score in our cohort increased by 0·20 cognitive domains during follow-up. After adjustment for multiple potential confounders, we showed that an MDS higher by 10 points was associated with a 7% reduction in the progression of SCD within one year. In terms of food groups, every additional vegetable serving consumption per day was associated with a 2·2% reduction in SCD progression per year. Our results provide support to the notion that MeDi may have a protective role against the whole continuum of cognitive decline, starting at the first subjective complaints. This finding may strengthen the role of the MeDi as a population-wide, cost-effective preventive strategy targeting the modifiable risk factors for cognitive decline.