Dietary intervention and cognition across Alzheimer's disease biomarker levels: The MIND clinical trial.

BackgroundThe cognitive response to dietary interventions may differ according to levels of Alzheimer's disease-related plasma biomarkers.ObjectiveUsing data from the MIND clinical trial, we examined whether baseline biomarkers, including Aβ40, the Aβ42/40 ratio, and p-tau181, modified the association between the MIND diet and longitudinal change in global cognition.MethodsThe MIND randomized clinical trial enrolled 604 community-dwelling adults aged 65-84 years without cognitive impairment at baseline. Recruitment occurred from January 2017 to April 2018, with data collection continuing through June 2021. Participants were randomized in a 1:1 ratio to the MIND or control diet for 3 years, with counseling on diet adherence and weight loss support provided at the same frequency throughout the intervention. Annual change from baseline in a global cognitive composite z-score was derived from a 12-test battery, with higher scores indicating better cognitive performance.ResultsOf the 602 individuals included in the analysis, 391 (65%) were female, and the mean baseline age was 70.4 (SD = 4.2) years. Baseline levels of Aβ40 and p-tau181 modified the association between MIND assignment and longitudinal change in global cognition, with significant between-group differences in biomarker-related annual cognitive slopes for Aβ40 (β=0.027, 95%CI 0.006-0.048) and p-tau181 (β=0.023, 95%CI 0.002-0.043), but not for the Aβ42/40 ratio.ConclusionsThe association between the MIND diet intervention and cognition varied by baseline levels of Aβ40 and p-tau181, with greater improvement in cognitive scores in the MIND group than in the control group among individuals with higher biomarker levels.Trial Registration: ClinicalTrials.gov Identifier: NCT02817074.