Adherence to a Mediterranean diet and cognitive function in the Age-Related Eye Disease Studies 1 & 2

The objective was to determine whether closer adherence to the alternative Mediterranean Diet (aMED) was associated with altered cognitive function.

Observational analyses of participants (n = 7,756) enrolled in two randomized trials of nutritional supplements for age-related macular degeneration: Age-Related Eye Disease Study (AREDS) and AREDS2.

Odds ratios for cognitive impairment, in aMED tertile 3 (vs 1), were 0.36 (P = .0001) for Modified Mini-Mental State (<80) and 0.56 (P = .001) for composite score in AREDS, and 0.56 for Telephone Interview Cognitive Status-Modified (<30) and 0.48 for composite score (each P < .0001) in AREDS2. Fish intake was associated with higher cognitive function. In AREDS2, rate of cognitive decline over 5 to 10 years was not significantly different by aMED but was significantly slower (P = .019) with higher fish intake.

Closer Mediterranean diet adherence was associated with lower risk of cognitive impairment but not slower decline in cognitive function. Apolipoprotein E (APOE) haplotype did not influence these relationships.