Drinking red wine in moderate amounts is considered healthy because of the presence of desirable antioxidant chemicals which are derived from the grapes used for making these products. Resveratrol, a chemical present in grapes is supposed to be both cardio-protective as well as chemo-protective, though these findings are based on animal studies. Indirectly, the relatively low incidence of cardiac disease amongst French population which consumes high levels of red wines has been attributed to the beneficial effect of chemicals present in wines which include Resveratrol, antioxidants, polyphenols, flavonoids, etc. Recent reports finding evidence for the beneficial effect of consuming just the grape extract further supports the already known facts about health impact of grape products. The findings that grape extracts can change the profile of fats in the muscle cell membranes to resist insulin resistance contribute to the understanding of the role played by chemicals derived from grapes
"Researchers from the University of Montpellier in the South of France report that rats fed a high-fat and high-sugar diet but supplemented with grape polyphenols displayed a lower accumulation of fat in muscle tissues. Diets high in saturated fats are reported to worsen Insulin resistance, whereby cells do not respond adequately to the normal levels of insulin produced by the body – a marker of the onset of Diabetes, explained the researchers in the British Journal of Nutrition. The affect of fat on insulin sensitivity is said to occur via changes to the compositions of cell membranes, and particularly the phospholipids in the membrane. The new study sought to identify if consumption of a polyphenol-rich extract from grapes could change the composition of fat in muscle cell membranes, with a particular focus on phospholipids and triglycerides".
There are hundreds of publications singing the virtues of wine consumption but almost all the studies were made using animals like rats, raising the inevitable question regarding their applicability in humans. What is lacking is hard data based on clinical studies using human subjects which may be difficult to organize due to practical problems in getting critical size of population needed to scientifically establish the truth. Nonetheless broad indications emerging from animal studies on products, can still serve as a practical guide for humans as long as they are safe for consumption.