Introduction: The Mediterranean diet (MeDi) has been related to a lower risk of Alzheimer's disease; yet, the underlying mechanisms are unknown. We hypothesized that protection against neurodegeneration would translate into higher gray matter volumes, whereas a specific association with preserved white matter microstructure would suggest alternative mechanisms (e.g., vascular pathways).
Methods: We included 146 participants from the Bordeaux Three-City study nondemented when they completed a dietary questionnaire and who underwent a 3-T magnetic resonance imaging at an average of 9 years later, including diffusion tensor imaging.
Results: In multivariate voxel-by-voxel analyses, adherence to the MeDi was significantly associated with preserved white matter microstructure in extensive areas, a gain in structural connectivity that was related to strong cognitive benefits. In contrast, we found no relation with gray matter volumes.
Discussion: The MeDi appears to benefit brain health through preservation of structural connectivity. Potential mediation by a favorable impact on brain vasculature deserves further research.
Keywords: Diffusion tensor imaging; Mediterranean diet; Neuroimaging; Prospective studies; Risk factors in epidemiology; Voxel-based morphometry.
Copyright © 2015 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.