Lower risk of incident dementia among Chinese older adults having three servings of vegetables and two servings of fruits a day

Background: dietary modification can potentially reduce dementia risk, but the importance of fruits and the amount of vegetables and fruits required for cognitive maintenance are uncertain. We examined whether the minimal daily requirement of vegetables and fruits recommended by the World Health Organization (WHO) would independently lower dementia risk. Methods: in this population-based observational study, we examined the diet of 17,700 community-living dementia-free Chinese older adults who attended the Elderly Health Centres in Hong Kong at baseline and followed their cognitive status for 6 years. In line with the WHO recommendation, we defined the cutoff for minimal intake of vegetables and fruits as at least three and two servings per day, respectively. The study outcome was incident dementia in 6 years. Dementia was defined by presence of clinical dementia in accordance with the 10th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) or Clinical Dementia Rating of 1-3. Results: multivariable logistic regression analysis showed that the estimated odds ratios for incident dementia were 0.88 (95% confidence interval 0.73-1.06; P = 0.17) for those consuming at least three servings of vegetables per day, 0.86 (0.74-0.99; P < 0.05) for those consuming at least two servings of fruits per day and 0.75 (0.60-0.95; P = 0.02) for those consuming at least these amounts of both at baseline, after adjusting for age, gender, education, major chronic diseases, physical exercise and smoking. Conclusion: having at least three servings of vegetables and two servings of fruits daily might help prevent dementia in older adults.