Trans-resveratrol is a phytoalexin, a natural plant phenol found in fruits and berries, including grapes, that helps product the plant from various types of environmental stress. It is commonly found in significant amounts in red wine (1).
Resveratrol is commonly considered to be an anti-aging life-extending substance which leads to the belief that it’s healthy to consume red wine preferentially over other alcoholic beverages (4).

Research has shown resveratrol to have a protective effect on cardiovascular health, improve insulin sensitivity, and longevity in individuals who are otherwise healthy (2).

Resveratrol was discovered in wine several thousand years ago; in Ayurveda it is referred to as “draksha”, meaning fermented grape juice (3).

With respect to cognition and neurology, resveratrol supplementation appears to increase blood flow to the brain, and it may interact with mechanisms involved in beta-amyloid accumulation (implicated in the pathogenesis of Alzheimer’s disease), and may increase intercellular signaling between neurotransmitters in the glutaminergic pathway (5, 6, 7). It is also involved in many enzymatic processes related to neuroprotection, though more research is needed to confirm (10, 11, 12).

With respect to longevity, resveratrol is thought to act primarily upon the Sirtuin system, which is involved in maintaining cellular integrity and is directly related to longevity and how the body reacts to stressors (8, 9). Again, the research is not conclusive, but long-term supplementation of resveratrol appears to support both cardiovascular health and insulin sensitivity. 

Resveratrol doses range from a low of 5 - 10 mg/day, though larger doses in the range of 150 - 445 mg/day have been used (13).