Mediterranean-DASH Intervention for Neurodegenerative Delay diet and risk of dementia: three prospective studies and meta-analysis of cohort studies

Abstract

AbstractObjectiveTo evaluate the association of Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet with risk of dementia in three prospective cohort studies, and to conduct a meta-analysis of cohort studies.Design & SettingThree prospective cohort studies – the Whitehall II study (WII, mean follow-up=13.2 years), the Health and Retirement Study (HRS, mean follow-up=4.3 years) and Framingham Heart Study Offspring cohort (FOS, mean follow-up=10.4 years), and meta-analysis of cohort studies.ParticipantsWe included 18163 middle-aged and older women and men (8360 in WII, 6758 in HRS, and 3045 in FOS) without baseline prevalent dementia for cohort analyses.Main outcome measuresIncident all-cause dementia, with cohort-specific definitions.ResultsThe mean (SD) of baseline MIND diet score (range: 0-15) was 8.3 (1.4) in WII, 7.1 (1.9) in HRS, and 8.1 (1.6) in FOS. Over 171,079 person-years, a total of 802 participants (222 in WII, 338 in HRS, and 242 in FOS) developed incident dementia. In the multivariable-adjusted model, every 3-point increment in MIND diet score (range: 0-15) was related to 20% decreased risk of dementia (pooled hazard ratio (HR) = 0.80; 95% confidence interval (CI): 0.70-0.91, P-trend=0.0014, P-heterogeneity=0.3039). In the WII, the corresponding HRs (95% CIs) was 1.04 (0.71-1.52) for remote MIND score in 1991-1993, and 0.76 (0.53-1.09) for recent score in 2002-2004. In the FOS, the HRs were 0.66 (0.50-0.86) for MIND score in 1991-1995 and 0.67 (0.51-0.88) for that in 1998-2001, respectively. In the meta-analysis of eleven cohorts with 224,140 participants, the highest category of MIND diet score was related to 18% lower risk of dementia (pooled relative risk: 0.82, 95% CI: 0.74-0.92, I2=74%, P-heterogeneity<0.01) compared with the lowest category.ConclusionsAdherence to the MIND diet was related to lower risk of incident dementia in middle-aged and older adults. Further studies are warranted to develop and refine the specific MIND diet for different populations.Systematic review registrationINPLASY202270127Summary boxWhat is already known on this topic-Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet has been proposed as a healthy dietary pattern for human brain.-The relation of MIND to incident dementia was relatively inconsistent and inconclusive in previous cohort studies.What this study adds-Results from the cohort analyses and the meta-analysis confirmed that adherence to the MIND diet is prospectively related to lower risk of incident dementia.-Results in current studies are heterogeneous across different populations, calling for further investigations into the culture-specific MIND diet.