journal articles
ASSOCIATION BETWEEN PLANT-BASED DIETS AND INCIDENT DEMENTIA: RESULTS FROM PROSPECTIVE COHORT STUDIES AND A META-ANALYSIS
Jie Shen, Hui Chen, Yiying Gong, Yuhui Huang, Minyu Wu, Yuxuan Gu, Tian Wang, Luigi Fontana, Shuang Rong, Shujiao Qian, Maurizio Tonetti, Xiaoran Liu, Changzheng Yuan
J Prev Alz Dis 2026;2(13)
BACKGROUND: Plant-based diets are increasingly advocated for their health benefits, yet their associations with dementia risk remains inconclusive. We evaluated the associations between plant-based dietary patterns and dementia risk across three prospective cohorts and a meta-analysis.
METHODS: Cohort analyses included the Health and Retirement Study (HRS; N = 6642), Framingham Heart Study Offspring cohort (FOS; N = 3045), and Whitehall II study (WHII; N = 8219). Participants were aged ≥45 years and free of dementia at baseline. The overall plant-based diet index (PDI), healthful plant-based diet index (hPDI) and unhealthful plant-based diet index (uPDI) were calculated from validated food frequency questionnaires. Further, a meta-analysis was conducted incorporating data from 5 cohort studies (N = 207,981).
RESULTS: In the cohort analyses, 891 incident dementia cases were identified over 166,762 person-years. In multivariable-adjusted Cox proportional hazard models, higher scores in PDI and hPDI were associated with lower risk of dementia (highest vs. lowest tertile: pooled HR for PDI = 0.70, 95% CI, 0.53–0.92, p for trend <0.001; pooled HR for hPDI = 0.71, 0.48–1.06, p for trend = 0.03). Main contributors to lower risk were higher intake of vegetables, nuts, tea or coffee, and legumes. Conversely, higher uPDI was associated with higher dementia risk (highest vs. lowest tertile: pooled HR = 1.42, 1.19–1.70, p for trend <0.001). In the meta-analysis, individuals in the highest hPDI tertile had 21% lower dementia risk, and those in the highest uPDI tertile had 24% higher risk.
CONCLUSIONS: The healthful plant-based diet was associated with lower risk of dementia, whereas the unhealthful plant-based diet was linked to higher risk. These findings support recommendations to adopt diets rich in healthy plant foods for dementia prevention.
CITATION:
Jie Shen ; Hui Chen ; Yiying Gong ; Yuhui Huang ; Minyu Wu ; Yuxuan Gu ; Tian Wang ; Luigi Fontana ; Shuang Rong ; Shujiao Qian ; Maurizio Tonetti ; Xiaoran Liu ; Changzheng Yuan (2025): Association between plant-based diets and incident dementia: results from prospective cohort studies and a meta-analysis. The Journal of Prevention of Alzheimer’s Disease (JPAD). https://doi.org/10.1016/j.tjpad.2025.100457