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

Background The cognitive response to dietary interventions may differ according to levels of Alzheimer's disease–related plasma biomarkers. Objective Using data from the MIND clinical trial, we examined whether baseline biomarkers, including Aβ 40 , the Aβ 42/40 ratio, and p-tau181, modified the association between the MIND diet and longitudinal change in global cognition. Methods The 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. Results Of 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 Aβ 40 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 Aβ 40 (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 Aβ 42/40 ratio. Conclusions The association between the MIND diet intervention and cognition varied by baseline levels of Aβ 40 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