Polyphenols, members of phytochemical superfamily rich in vegetables and fruits, include flavonoids, non-flavonoids, and phenolic acids. Their biological effects includes classical antioxidation (e.g., radical-scavenging, metal chelating, NOX inhibition, attenuation on mitochondrial respiration, inhibition on xanthine oxidase, and upregulations on endogenous antioxidant enzymes), multiple regulations on cell signaling (e.g., AMPK activation, SirT1 activation, eNOS activation, FOXO activation, NF\kappaB inactivation, PI3K/AkT inhibition, mTORC1 inhibition, PKC inhibition, MAPK inhibition, ERK inhibition, JAK/STAT inhibition, IKK/JNK inhibition, PDE inhibition, \beta-catenin inactivation, downregulation on TLR expression, ACE inhibition, adiponectin elevation, attenuated ET-1 production, and K{}^{+} channel activation), and many other actions (e.g., inhibition on \alpha-glucosidase, anticoagulation, \gamma-secretase inhibition, monoamine oxidase inhibition, LPL upregulation, ANGPTL4 suppression, upregulation on paraoxonase 1, PAI-1 downregulation, tPA upregulation, immunoregulation, epigenetic modulation, and altered gut microbiota). Such multi- targeting and functions exhibiting antioxidative stress and antiinflammation as major pillars along with many other antagonisms could not only afford healthy polyphenols suitable supplements for promoting health, but also advance them to therapeutic applications. This review aims to translate diverse polyphenolic biochemical actions to clinical applications in fighting against non-communicable diseases such as CVD, cancer, diabetes, obesity, neurodegeneration, inflammatory diseases (e.g., IBD, IBS, NAFLD, etc.), AMD, allergy, and autoimmunity as well as communicable infection (e.g., bacteria, fungal, and viral).