"In particular, red wines are rich in polyphenols, a group of powerful antioxidants that are thought to protect against cancer and heart disease by destroying molecules that would otherwise damage cells. How the polyphenols in wine exercise their beneficial effects, though, has been mysterious."

" The answer, Dr Kanner has found, lies in the stomach itself. The digestion of high-fat foods such as red meat releases oxidising toxins. One in particular, called malondialdehyde, is implicated in arteriosclerosis, cancer, diabetes and a host of other serious diseases. Dr Kanner suspected that the key to wine’s protective effect is when, precisely, it is consumed. He hypothesised that if the polyphenols arrive in the stomach at the moment when the fats are releasing malondialdehyde and its kin, then this might stop these toxic materials from getting any farther into the body.
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As he reports in the Journal of Agricultural and Food Chemistry, the wine concentrate did indeed reduce the formation of malondialdehyde. It also cut the level of hydroperoxides, another group of oxidising agents that cause cell damage."

" Many fruits, too, are rich in polyphenols (wine is, after all, just fermented fruit juice). By treating them as dessert, these fruits arrive in the stomach at the point when meat-digestion is poised to do its worst—nipping the problem in the bud, as it were."