Quercetin daily consumption

Quercetin occurs in many medicinal plants, for example Hypericum and Crataegus, as well as in fruits and vegetables. It is estimated that the average daily consumption in the diet is 25 mg. Because of its ubiquitous occurrence it has been studied extensively to ascertain if the strong mutagenicity has relevance to human health. In vivo studies have generally yielded negative results. A 2-year study in rats... 

The Zutphen Elderly study thus suggests that regular flavonoid consumption, as part of the food matrix, may reduce the risk of death from CHD in elderly men. This study also provides evidence for flavonoid-mediated protection against stroke. Dietary flavonoids (particularly quercetin) were inversely associated with stroke incidence. The relative risk of the highest versus the lowest quartile of flavonoid was 0.27 (95% confidence interval, 0.11-0.70). Black tea contributed approximately 70% to flavonoid intake and the relative risk for a daily consumption of 4.7cups or more of tea versus less than 2.6 cups of tea was 0.31 (95% confidence interval, 0.12-0.84). This study also found that intake of catechins, whether from tea or other sources (e.g., chocolate), may reduce the risk of ischemic... 

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