Midlife Fruit and Vegetable Consumption and Risk of Dementia in Later Life in Swedish Twins

Objective: Diet may be associated with risk of dementia and Alzheimer disease (AD). The authors examined the association between fruit and vegetable consumption in midlife and risk for all types of dementia and AD. Methods: Participants were 3,779 members of the Swedish Twin Registry who completed a diet questionnaire approximately 30 years before cognitive screening and full clinical evaluation for dementia as part of the study of dementia in Swedish Twins (HARMONY) study. Among the participants, 355 twins were diagnosed with dementia. Among these, 81 twin pairs were discordant for dementia (50 discordant for AD). Data were analyzed with logistic regression for the entire sample using generalized estimating equations to adjust for relatedness of twins and with conditional logistic regression for the co-twin control design. Results: In fully adjusted models, a medium or great proportion of fruits and vegetables in the diet, compared with no or small, was associated with a decreased risk of dementia and AD. This effect was observed among women and those with angina. Similar, but nonsignificant, odds ratios were found in the co-twin control analyses. Conclusion: The findings suggest that higher fruit and vegetable consumption may reduce the risk of dementia, especially among women and those with angina pectoris in midlife. (Am J Geriatr Psychiatry 2010; 18: 413-420)