Association of Nut Consumption with Dementia and Alzheimer's Disease

Background: Nut consumption reduces risks of cardiovascular disease, respiratory disease and depression. However, its association with dementia and Alzheimer's disease (AD) remains unclear. Methods: A population-based case-control study was conducted in China, including 466 participants aged 52-100 years (233 with dementia). Data on socio-demographic characteristics, lifestyle factors, comorbidities, and dietary intake over the past two years were collected through structured face-to-face interviews. Nut consumption was categorised as non-consumption or <monthly, ≥monthly but <weekly, ≥weekly but <daily, daily, and ≥twice daily. Multiple adjusted logistic regression models were employed to examine the association of nut consumption with dementia and AD. Results: Of the 466 participants, 59.0% reported consuming nuts at non-consumption or <monthly, 22.5% monthly, 11.8% weekly, 6.0% daily, and 0.6% ≥ twice daily. Compared with non-consumption or <monthly consumption, the age-adjusted odds ratio (OR) for dementia was 0.31 (95% CI 0.18-0.52) for monthly intake, 0.52 (0.28-0.97) for weekly intake, and 0.32 (0.14-0.72) for daily or higher intake. After further adjustment for gender, education, family income, marital status, smoking, stroke, chronic bronchitis, depression, and other dietary intakes, OR was 0.27 (0.13-0.55) for monthly intake and 0.47 (0.23-0.99) for ≥weekly intake. Among 133 participants with AD, similar associations were observed, with a fully adjusted OR of 0.34 (0.17-0.69) for ≥monthly nut consumption. Conclusions: Higher nut consumption was associated with reduced risks of dementia and AD. Increasing nut intake may represent a potential strategy for dementia and AD prevention. However, large-scale cohort and interventional studies are needed to further clarify the association and determine the magnitude of the effect.