Specific vegetable types are associated with lower long-term risk for late-life dementia: the Perth Longitudinal Study of Aging Women

Abstract

This study examined the relationship between total vegetable intake, including specific vegetable types with long-term late-life dementia (LLD) risk in older Australian women. 1206 community-dwelling older women aged ≥70 years were included. Consumption of total vegetable intake and vegetable types (yellow/orange/red [YOR], cruciferous, allium, green leafy vegetables [GLV], and legumes) were estimated using a validated food frequency questionnaire at baseline (1998). LLD was considered any form of dementia occurring after 80 years of age. LLD events (comprising hospitalisation and/or death) were obtained from linked health records. Associations were examined using restricted cubic splines within multivariable-adjusted (including APOE4 genotype) Cox proportional hazard models. Over 14.5 years of follow-up (∼15 134 person-years) there were 207 (17.2%) LLD events, 183 (15.25%) with LLD hospitalisations and 83 (6.9%) with LLD deaths. Compared to women in the lowest Quartile (Q1) of total vegetable intake, those with higher intakes (Q3, but not Q4) had 39% lower hazard for a LLD death. Compared to Q1, women in the highest quartile of YOR intake (Q4) consistently recorded lower hazards for a LLD event (47%), hospitalisation (46%), and death (50%). Similarly, women with the highest allium intake (Q4), had lower hazards for LLD events (36%) and deaths (49%), compared to Q1. Women with the highest GLV intake (Q4) also recorded 45% lower hazards for a LLD death. Whilst total vegetable intake may be important, allium, GLV and especially YOR vegetables may be most beneficial when considering LLD risk. These results require further validation in other cohorts, including men. The clinical trial registry numbers are https://anzctr.org.au/Trial/Registration/TrialReview.aspx?id=368778&isReview=true, CAIFOS: ACTRN12615000750583, and https://anzctr.org.au/Trial/Registration/TrialReview.aspx?id=372818&showOriginal=true&isReview=true, PLSAW: ACTRN12617000640303.