Collectively these compounds are called lignin-derived polyphenols, which bear a relationship to polyphenols from grape skin and seeds. These molecules are often aromatic, vanilla being a good example. And the prolonged time that red wines often spend in barrels can result in a high degree of extraction into the wine, though levels may still be small in comparison. Nevertheless, their contribution to wine’s effects on health may be as important as their input to flavor and structure, according to recent research.
A study from the University of Alabama found impressive antioxidant capabilities of lignin polyphenols, with free radical scavenging potency in the same range as wine phenolics. Of particular interest is that these compounds bind many of the same proteins as resveratrol, indicating they may send similar metabolic signals. The authors of the study concluded that oak phenolics may contribute to cancer prevention and heart disease prevention to a significant degree.
Traditional methods of winemaking are on the decline though, and the effects of newer techniques such as micro-oxygenation instead of prolonged barrel aging may change the composition of the final product. Oak chips are being substituted for the barrel, which may or may not impart similar compounds. To be sure, barrels are one of the more costly aspects of winemaking, but I guess I am a traditionalist. I am willing to let the angels have their share (the evaporative loss from aging in oak) in return for something I know is good.