Higher MIND diet scores are associated with larger brain MRI hippocampal volume: the cross‐cohort collaboration

Abstract Background Higher Mediterranean‐ DASH for Neurodegenerative Delay (MIND) diet scores have previously been associated with larger total brain volume (TBV) in the Framingham Offspring Study (FOS) community‐based cohort. We investigated cross‐sectional relationships between the MIND diet and structural brain imaging volumes and white matter hyperintensity volume (WMHV) across six community‐based cohorts. Method We analyzed data from 3130 dementia‐, stroke‐ and other neurological disease free adults (aged 65 to 74) who participated in the Atherosclerosis Risk in Communities (ARIC) cohort, Cardiovascular Health Study (CHS), Three City (3C) cohort, FOS cohort, Rotterdam Study (RS) or the Study of Health in Pomerania (SHIP) cohort. Individuals completed a brain magnetic resonance imaging (MRI) scan, and a validated food frequency questionnaire (FFQ) (ARIC, CHS, FOS, RS), 24h dietary recall (3C), or an extensive food list (SHIP). The MIND diet consists of ten healthy (e.g. green leafy vegetables, berries and fish) and five unhealthy (e.g. cheese, red meat and products and fast fried foods) components. Outcomes from brain MRI included TBV, total grey matter volume (TGMV), hippocampal volume (HPV), and WMHV. We used multivariable linear regression to relate MIND diet adherence to the outcomes. Results were combined in meta‐analysis using fixed effects and random effects models. Result Higher MIND diet scores (score range: 0‐15) were associated with larger HPV (beta = 0.015, 95% confidence interval = 0.004 to 0.026, cm³ per one unit MIND diet score increase) after adjustment for age, age squared, sex, time from clinical exam to brain MRI exam, total intracranial volume and energy intake, but not with TBV, TGMV and WMHV. Heterogeneity between studies was low (I 2 = 0% TBV, TGMV, HPV) to moderate (I 2 = 44% WMHV). Conclusion In cross‐sectional analyses, higher MIND diet scores were associated with larger HPV, but not with other brain volume measures. It might be that HPV was a more sensitive marker of brain health in the populations under study. Future studies are encouraged to examine the associations between the MIND diet and amyloid and tau positron emission tomography (PET) imaging to elucidate whether a relationship between the MIND diet and dementia pathologies exists.