Fruit, vegetable intake lowers risk of dementia

Consumption of fruits and vegetables may help prevent the development of dementia, suggests a study.

Researchers collected data from the Health and Retirement Study (HRS), the Framingham Heart Study Offspring Cohort (FOS), and the Whitehall II Study (WHII). They assessed the mean daily intakes of total vegetables and fruits, and seven subgroups, using food frequency questionnaires and identified incident dementia using cohort-specific definitions.

Hazard ratios (HRs) and 95 percent confidence intervals (CIs) were estimated using Cox regression models. A meta-analysis was also conducted to integrate the findings from 13 previous cohort studies.

A total of 18,339 participants aged ≥45 y (HRS: n=6,750; FOS: n=3,068; WHII: n=8,521) were included in the analysis. Of these, 936 developed dementia over an average 7‒13 years of follow-up.

After multivariable adjustment, an association was observed between intake of total fruits and vegetables and a reduce dementia risk in the highest vs lowest tertile (T3 vs T1: HR, 0.74, 95 percent CI, 0.61‒0.89; p_trend=0.165).

Notably, green leafy vegetables showed a protective association (pooled HR per serving increment, 0.82, 95 percent CI, 0.70‒0.96; p_trend=0.015). Significant pooled associations for other vegetable or fruit subgroups were not observed.

Pooled findings from a meta-analysis of 222,108 participants showed an association between an increased intake of fruits and vegetables and a lower risk of dementia compared with a lower intake (pooled HR, 0.80, 95 percent CI, 0.71‒0.91).

Intakes of vegetable (pooled HR, 0.87, 95 percent CI, 0.82‒0.92) and fruit (pooled HR, 0.90, 95 percent CI, 0.85‒0.95) also showed significant inverse associations with dementia risk.

“Further studies on specific subgroups are warranted,” the researchers said.