I'm confused about benefits and/or problems associated with natural polyphenolic pigments in foods. In a recent thread, it was mentioned that a polyphenonol in buckwheat sprouts can accumulate in the skin and translate certain light wavelengths into skin damage. St John's Wort is also associated with the same phenomenon. The polyphenols absorb certain bandwidths of light, translate the light waves to energy, and thus oxidize amino acids in the skin and kill skin cells. In the horse world, intake by horses of various polyphenols in various plants is also a well known cause of similar skin problems and damage.
Yet polyphenolic pigments are considered skin protective antioxidents in other quarters by people who say they accumulate in skin and thus PROTECT the skin. However, the wiki page: http://en.wikipedia.org/wiki/Polyphenol seems to indicate in vivo research has not reached any strong conclusive agreement on benefits of polyphenol intake. Can anyone help clarify this issue? Over time, I have found myself becoming more suspicious of many of the antioxident claims for various foods. Seems like much of the supposed research results is not robust and it open to a large amount of interpretation.
asked byEva (20807)
Get FREE instant access to our Paleo For Beginners Guide & 15 FREE Recipes!
on February 06, 2011
at 10:44 PM
The question is super interesting, from the standpoint of biochemistry, but it reminds me of many such questions, which are really requests for help with research rather than simple queries about facts.
On the other hand, there's nothing really "paleo" about eating grain, sprouted or not. Right?
on February 07, 2011
at 12:48 AM
Just stick to getting your "polyphenols" from real foods, and not supplements, and in moderate amounts - and you have nothing to worry about. Like any other bioactive substances, they likely have both positive and negative effects, and an optimal range of intake. They're also not a monolithic group of chemicals by any means, and have widely different chemical activity. Some we know have strong beneficial effects, and some we know have strong toxic effects. Even within the spectrum of effects on light sensitivity of skin, there's a wild range of possible activity - carotenes and some fern polyphenols seem to protect, while psoralens (not technically polyphenols, but often considered as such) clearly harm
At the very least, their direct, systemic antioxidant abilities when obtained from the diet are almost totally bunk. They're minimally absorbed, and quickly processed/removed. The increased antioxidant capacity of the blood resulting from their intake has been demonstrated to be the result of endogenous antioxidant systems like uric acid and glutathione. Other effects have been clearly linked to the induction of powerful "detoxifying" and protective enzyme systems. Hormesis at work :) Thus ORAC capacity is a silly measure, from what I can gather.