Objective: Dietary flavonoids and their metabolites may have neuroprotective effects against age-associated neurodegenerative disorders such as Alzheimer's and related dementias (dementia). There is a lack of population studies, however, on correlations between flavonoid intake and dementia. The main objective of the present study was to analyse such a relationship at a large-scale population level. Design: Based on global data (FAO, WHO), databases were generated for: (i) flavonoid content of foods; (ii) per capita national dietary intakes of flavonoids and other dietary factors; and (iii) disability-adjusted life years -a measure of burden and death -due to dementia. Five major flavonoid subclasses were examined. To minimize influences due to accuracy and reliability of the disease source data, twenty-three developed countries were selected after statistical evaluation. Results: Flavonols and combined flavonoids (all five combined) intakes were the only two parameters with significant (P , 0?05) negative dementia correlations. Multiple linear regression models confirmed this relationship, and excluded confounding from some other dietary and non-dietary factors. Similar analyses with non-dementia, neurological/psychiatric diseases did not yield significant correlations. Conclusions: At a global level, and in the context of different genetic backgrounds, our results suggest that higher consumption of dietary flavonoids, especially flavonols, is associated with lower population rates of dementia in these countries.

Accurate estimates of flavonoid intake are important for public health studies and potential policies related to these phytochemicals. As an alternative to studies involving population samples and individual food consumption surveys, the international FAO Food Balance Sheets (FBS) were used in the current study to estimate flavonoid consumption among the populations of the UK and Republic of Ireland. A supplemented USDA database was prepared for flavonoid analyses of the foods reported in the FBS. Twenty-three flavonoids from five groups (anthocyanidins, flavonols, flavanols, flavanones, and flavones) were analyzed. Estimated per-capita daily flavonoid intake (all five groups) was 182 mg and 177 mg for the UK and Ireland, respectively. In both cases, anthocyanidins and flavanols accounted for about 65% of total consumption. Combined intake of flavones, flavanones, and flavonols was 60 mg/day in the UK and 69 mg/day in Ireland. These flavonoid intake values are compared with those previously reported for the UK and other countries. Overall, these novel results contribute to establishing accurate reference points for national flavonoid intakes.

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