Current Understanding of Dietary Polyphenols and their Role in Health and Disease

Polyphenols are among a wide variety of active photochemicals present in the human diet. Basic researches and epidemiological studies have shown the inverse association between risk of cancer, CVDs, diabetes, several age related chronic diseases and intake of diet rich in polyphenols. Recent researches have opened the possibility of dietary polyphenols to be considered as phytomedicine. Most of the studies on the bioactivity of polyphenols have been conducted on animal models and in in vitro systems, direct studies on humans are few and results inconclusive. The bioavailability and biotransformation of polyphenols in humans needs to be studied. The present review provides an update about dietary polyphenols covering their nature, occurrence, bioavailability, and possible health benefits in relation to human diseases.