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 ==Is this a review that misses the forest for all the trees?== 
 The problem with this review visit focuses on all kinds of arcane chemical and terminological issues, instead of the research on polyphenols that demonstrates that they are enormously protective biological compounds with a highly pleiotropic physiologic signature.  I doubt very much that people want to read this much arcane chemistry and certainly not this much hairsplitting about chemical terminology.  The more important issue is how and why polyphenols are a fundamental component of the human diet and have been for tens of thousands of years, if not longer and exactly how they function as protective compounds.  I don't have enough time unfortunately pitch in on this effort, but I'm cutting and pasting below a brief overview from a book chapter (which I wrote) emphasizing the enormously complex and fundamentally protective effects that these compounds have.  It's troubling that this review doesn't really address any of these issues. I wish I had time to pitch in on a major rewrite of this, but this is all I can contribute.for referencing on this little snippet, see Watt, DF  (2012) The biology of aging: implications for understanding the diseases of aging and healthcare in the 21st century.  Contributed chapter in Textbook of Geriatric Neurology.  (Eds Nair and Sabbagh).  In press for 2012. 

 ""Although conventionally regarded as antioxidants, polyphenols are an enormous class of substances (constituting perhaps as many as 6,000 distinct compounds) found in plants, principally fruits and vegetables, that have enormously pleiotropic effects on human and mammalian physiology. Some of these effects may be more biologically significant than any direct “free radical scavenging” done by a polyphenol; they include many effects on cell signaling, the regulation of growth factors and apoptosis, the regulation of cell cycling, the regulation of inflammation, the modulation of many (if not most) cellular stress pathways, an impact on multiple transcription factors (including those involved in energy homeostasis), and (consistent with their conventional designation) the management of oxidative stress (Virgili and Marino 2008). Many of these effects on aspects of cell signaling require much lower levels of polyphenol than any direct free radical scavenging in serum or tissues. Indeed, from this perspective, polyphenols look less like antioxidants and more like complex cell physiology and cell signaling modulators. However, it seems unlikely that such a designation will replace the catchy title of “antioxidant,” even in the context of increasing evidence that such a title may be fundamentally misleading. Many, if not most, of the phenotypes of aging (oxidative stress, mitochondrial dysfunction, inflammation, and declining autophagy, among others) appear to be partially modulated by various polyphenols. From this perspective, if our ancestors consumed more plants than we do, and did so over tens of thousands of years (if not longer), the relative removal of polyphenols from the human diet (in those eating minimal fruits and vegetables) would be predicted to have complex but potentially profound effects on physiology and the trajectories of aging.  Conversely, those eating a rich variety of plants may be more protected against accelerated aging and the diseases of aging.  Of these two predictions, the second has been better studied, and is generally supported. 

 Polyphenols consist of several classes of chemical substances, including nonflavonoid compounds (such as resveratrol, other stilbenes, and curcuminoids), and classic flavonoids (consisting of two large classes, anthocyanins, which are colorful and pigmented, and anthoxantins, which are colorless). Resveratrol and its first cousin, pterostilbene, are both naturally occurring phytoalexins produced by plants in response to fungal infection (phytoalexins are all “plant defense” compounds). Of the anthoxantin family, quercetin is one of the best-known and best-studied members, along with EGCG (a member of the catechins family, with catechins constituting a large group of polyphenols in tea and wine). Dietary sources for polyphenols include many foods that have been ancient components of the human diet for many hundreds and even thousands of years: fruits and their juices (typically containing both anthocyanins and anthoxantins), tea (catechins), coffee (chlorogenic, caffeic and ferulic acids), red wine (anthocyanins, resveratrol, and quercetin), vegetables (many anthoxantins and anthocyanins), some cereals, chocolate (multiple flavonoids, including catechins and proanthocyanidins), and various legumes, particularly soy (isoflavones) and peanuts.  

 In this context, there are multiple challenges to any emerging science that might explain the roles polyphenols could play in health maintenance and the slowing of at least some aspects of aging. First, there