Seems like every other day there's something that's supposedly good for you found, and the nutritional supplement industry marketing machine goes into motion pushing this "latest and greatest discovery ever". One such ingredient pushed was "resveratrol".
Resveratrol is a certain naturally occurring chemical that's contained in grape skin and skin of some other fruits. It was suspected as one of the reasons why the French seem to have low instances of heart disease despite their high-fat diet compared to the Americans. However, the link has yet to be definitely established. That of course, did not prevent any of the nutritional supplement companies from claiming this is good for you.
Wine contain such minute amount of resveratrol that it's almost not worth mentioning. You need to drink liters of it to get a decent dose.
There have been study of this ingredient for various symptoms and diseases, such as heart disease, diabetes, and more. Most are inconclusive, showing slight positive results but without definite relation between the ingredient and improvement.
In other words, there is no PROVEN benefit, merely suspected benefit, from taking resveratrol.
Marketing, on the other hand, had blown this ingredient out of proportion since 2006.