With potent antioxidant properties, do dietary flavonoids truly benefit human health? This review explores the bioavailability, metabolic effects, and safety of flavonoids, a large and diverse group of plant polyphenols that contribute to the flavor and color of fruits and vegetables. The six major subclasses of flavonoids include flavones, flavonols, flavanones, catechins, anthocyanidins, and isoflavones. Human feeding studies suggest that the absorption and bioavailability of specific flavonoids are higher than previously thought. However, epidemiologic studies examining the role of flavonoids in human health provide inconclusive results, with some supporting a protective effect against cardiovascular disease and cancer, others showing no effect, and a few suggesting potential harm. Given the diverse biological activities attributed to flavonoids, further research is needed to fully understand their effects on human health. Future investigations should focus on the specific circumstances under which flavonoids may be beneficial or detrimental, guiding dietary recommendations and potential therapeutic applications.
Published in the _Annual Review of Nutrition_, this review article directly addresses the journal's core focus on the role of nutrients in human health. By examining the bioavailability, metabolic effects, and safety of dietary flavonoids, the paper contributes to the ongoing discussion about the impact of plant-based compounds on nutrition and disease prevention.