A medium glass of wine is equivalent to
about 2 units of alcohol.
According to "Dietary Guidelines for Americans 2010"4, published by the US Department of Agriculture, "If alcohol is consumed, it should be consumed in moderation - up to one drink per day for women and two drinks per day for men".
The National Health Service5, UK, writes "Men should not regularly drink more than 3-4 units of alcohol a day. Women should not regularly drink more than 2-3 units a day." One unit equals 10ml or 8g of pure alcohol. A 250ml (large) glass of 12% red wine has about 3 units of alcohol. A 175ml (medium) glass has about two units.
Scientists from the University of Leicester, UK, reported at the 2nd International Scientific Conference on Resveratrol and Health that regular, moderate red wine consumption can reduce the rate of bowel tumors by approximately 50%.