There are several aspects to any health benefits of oak aged wines and spirits. The first component is the wine or spirit itself. It has been thought for a long time, and recent research seems to back it up, that moderate consumption of 1 or two alcoholic drinks per day can increase the average lifespan of an otherwise healthy person. It has been shown to raise the good HDL cholesterol, prevent blood platelet clumping and sticking which cause deadly blood clots that lead to heart attack and stroke, and also to combat prevent the taking on of parasites in regions where safe drinking water is not the norm. Wine and grape spirits contain many healthy polyphenol antioxidants, resveratrol, and gallic acid, which all combat cell damage which can lead to cancer. The action of antioxidants has long been known to give anticancer benefits, and the potent antioxidants in red wine, wine, and grape spirits, are no exception. Red wine has even more since the dark red pigment from the grape skins contains the most antioxidant content. Flavonoids and resveratrol go further by preventing the platelet stickiness that leads to deadly blood clots which result in heart attack and stroke.
The second aspect of oak aged spirits is a particularly potent antioxidant found in the oak barrels. It is the same antioxidant which is found in many fruits and vegetable matter, such as grapes, strawberries, walnuts, pecans, raspberries, pomegranates, and other natural produce. It is called ellagic acid, and it is highly concentrated in the oak wood that the aging barrels are made of. This chemical is leeched into the aging spirit during the lengthy oak aging. During the temperature fluctuations common in spirit aging environments, the liquid penetrates the wood barrel and comes out again, many times over, thus infusing the liquid with plenty of ellagic acid from the oak. This would happen with any oak aged liquid, most commonly aged wines, cognac, brandies, bourbon & scotch whiskies, and even some aged rums. All of these alcoholic beverages contain hefty amounts of ellagic acid, as well as the many other substances that are inherent in the drinks themselves before the aging process.
Ellagic acid has been shown to cause cell death in cancer cells. It is also thought that it prevents carcinogens from binding to DNA. As we all know, DNA damage passed on through replication can result in cancerous mutations. It also strengthens connective tissue resulting in the prevention of the cancer from spreading. Ellagic acid also reduces heart disease, liver fibrosis, birth defects, and it promotes wound healing. It has also been shown to prevent tumor growth, bladder cancer, breast cancer, esophageal cancer, leukemia, and prostate cancer. It is also antimicrobial.
Oak aged wines and spirits contain many health promoting compounds, as well as ellagic acid from grapes (in grape spirits and wine) as well as from the oak barrels which they are aged in. Remember that the key to integrating these drinks into a healthy diet is moderation. In the case of alcoholic beverages, more is not better, and you should stick to the one or two drink per day limit or risk turning a health benefit into a liability. Enjoy responsibly and you can have a longer and tastier life.