Examining the associations between fruit and vegetable intake and dementia in older adults from Japan Original paper

In this observational study, a higher intake of vegetables was associated with a lower incidence of dementia

This Study Summary was published on August 23, 2022.


Although the incidence of Alzheimer’s disease (AD) has increased in proportion to the aging population, by some estimates, the increased dementia trend is still observed even after accounting for age, suggesting the involvement of other, possibly modifiable factors.[1]

Studies in various Western populations have found that higher intakes of fruits and vegetables are associated with lower dementia risk, but there is limited evidence from Asian populations. This study examined the associations between fruit and vegetable intake and dementia in a Japanese community.

The study

In this observational study, 1,071 participants (ages > 60; 452 men, 619 women) in Japan were followed for 24 years. All of the participants were free of dementia at baseline, and their intakes of fruits, vegetables, and specific nutrients were assessed via food frequency questionnaires at baseline.

The primary outcomes were development of dementia or either of the dementia subtypes Alzheimer’s disease (AD) or vascular dementia (VaD).

The results

Overall, 464 participants developed dementia during the 24-year follow-up period (286 with AD and 144 with VaD).

  • A higher intake of vegetables was associated with lower risk of all-cause dementia and AD, but not VaD.
  • The highest 25% of vegetable intake in the cohort was associated with 27% decreased risk of dementia and a 31% decreased risk of AD compared to the lowest 25% of vegetable intake.
  • Dementia risk was also significantly decreased with increased intakes of vitamin C, vitamin A, riboflavin, calcium, magnesium, potassium, and dietary fiber.
  • There were no significant associations between fruit intake and dementia.

The authors concluded that a diet rich in vegetables may reduce dementia risk in Asian populations.

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This Study Summary was published on August 23, 2022.


  1. ^Ohara T, Hata J, Yoshida D, Mukai N, Nagata M, Iwaki T, Kitazono T, Kanba S, Kiyohara Y, Ninomiya TTrends in dementia prevalence, incidence, and survival rate in a Japanese community.Neurology.(2017-May-16)