Many times, I saw & heard scientists praising polyphenols as being antioxidants & anti-carcinogenic.
I have a reference for an article that have come from the University of Reading "a good one" but I cannot get full access to its contents. I wonder if your University can help you in getting it. My best wishes.
Article Characterization of protein–polyphenol interactions
If you cannot get it, these are the e-mail & the address of the main author:
For more information on polyphenol-food protein complexes, as well as byproducts of their degradation, you may refer to the following article: https://www.ncbi.nlm.nih.gov/pubmed/15640485