Many studies show people around the world who have 1-2 glasses of wine with dinner are healthier. If true, is that due to a benefit of alcohol in moderation as a mild stressor, or presence of beneficial nutraceuticals in the wine apart from alcohol, or a combination?

We can tell you that both things are true. Alcohol does have the benefit of being a source of eustress, the opposite of distress, meaning a perturbation that is negative in nature but not sufficient to be causing lasting harm although presenting a challenge to the body and, in overcoming that modest negativity, ends up strengthening and reinvigorating underperforming biochemical pathways, and so is a net positive once the mental impairment from being tipsy wears off. In addition, wine does have a number of beneficial nutraceuticals that have been appreciated and are being exploited through making extracts, not only from grapes used in winemaking but from wine itself, because the process of fermentation transforms some of the makeup in grapes biochemically to make them advantageous when ingested. So, in moderation, wine ingestion is beneficial, it is simply an unfortunate complication that some people, especially those with a karmic history of alcoholism, may find it difficult to constrain intake and it becomes a slippery slope leading to becoming a heavy drinker and a true alcoholic in the current life. This simply illustrates the wisdom in maintaining balance in all things.