Dietary flavonoids and human top-ranked diseases: The perspective of in vivo bioactivity and bioavailability

Cancers, cardiovascular and cerebrovascular diseases, and neurodegenerative diseases (NDs) are top-ranked diseases worldwide and for the elderly, they are the top three. In the past decade, dietary flavonoids have become one the of research topics of attention due to their definite protective and to some extent therapeutic effects on cancers, cardiovascular and cerebrovascular diseases, and NDs. In addition, to maximize bioactivities and the utilization of dietary flavonoids, recently great efforts have been devoted to the bioavailability enhancement of dietary flavonoids. Various dietary flavonoid extracts and pure dietary flavonoid molecules that display protective and/or therapeutic effects on cancers, cardiovascular and cerebrovascular diseases, or NDs are demonstrated. Only in vivo bioactive reports and findings with solid evidences (both human and animal-based ones) are compiled in this paper to exemplify the practical use of dietary flavonoids as complementary therapies for cancers, cardiovascular and cerebrovascular diseases, or NDs. Furthermore, the strategies for improving the bioavailability of dietary flavonoids are discussed. Key findings and conclusions: Both dietary flavonoid extracts and pure dietary flavonoid molecules can reduce the risk of cancers, cardiovascular and cerebrovascular diseases, or NDs. Many types of nano-systems like drug nanocrystals, polymer nanoparticles, solid lipid nanoparticles, and nanoliposomes can evidently increase the bioavailability and thereby the therapeutic index for dietary flavonoids. All these findings suggest the potential utility of dietary flavonoids as dietary supplements in the adjuvant therapy of cancers, cardiovascular and cerebrovascular diseases, and NDs.