Mediterranean diet, micronutrients and macronutrients, and MRI measures of cortical thickness

Abstract

Introduction: The Mediterranean diet (MeDi) is associated with reduced risk of cognitive impairment, but it is unclear whether it is associated with better brain imaging biomarkers.

Methods: Among 672 cognitively normal participants (mean age, 79.8 years, 52.5% men), we investigated associations of MeDi score and MeDi components with magnetic resonance imaging measures of cortical thickness for the four lobes separately and averaged (average lobar).

Results: Higher MeDi score was associated with larger frontal, parietal, occipital, and average lobar cortical thickness. Higher legume and fish intakes were associated with larger cortical thickness: legumes with larger superior parietal, inferior parietal, precuneus, parietal, occipital, lingual, and fish with larger precuneus, superior parietal, posterior cingulate, parietal, and inferior parietal. Higher carbohydrate and sugar intakes were associated with lower entorhinal cortical thickness.

Discussion: In this sample of elderly persons, higher adherence to MeDi was associated with larger cortical thickness. These cross-sectional findings require validation in prospective studies.

Keywords: Biomarkers; Cortical thickness; Cross-sectional studies; Diet; Fish; Fruit; Legumes; Macronutrients; Magnetic resonance imaging; Nutrition; Structural brain changes; Sugar; Vitamins.

Figure 1

Forest plots for associations (beta estimates [P-values]) of total MeDi score with cortical thickness for a) The 6 summary measures: average frontal, temporal, parietal, occipital, average composite thickness for the 4 lobes, and an AD signature cortical thickness. b) Individual regions of interest (ROIs). The squares represent beta estimates from general linear models adjusted for age, sex, education, BMI, vascular risk factors, stroke and depressive symptoms. The dark solid horizontal lines represent the 95% confidence intervals.

Figure 2

Forest plots of associations (beta estimates [P-values]) of components of MeDi score for (A) Fish; (B) Legumes; (C) Fruit; with cortical thickness for regions of interest (ROIs) for summary measures (listed first) and individual ROIs. The squares represent beta estimates from general linear models, adjusted for age, sex, education, BMI, vascular risk factors, stroke and depressive symptoms.