The only element that beer and wine have in common is alcohol, but that doesn't mean that beer has no health benefits. In fact, whether you prefer wine or beer, a glass or two per day appears to help protect heart health. A 2012 review of studies, published in the July 2012 issue of Nutrients, concluded that "regular and moderate" wine consumption (one to two glasses a day) is associated with decreased incidence of cardiovascular disease, high blood pressure, diabetes, and certain cancers, including colon, basal cell, ovarian, and prostate. On the other hand, some research links moderate alcohol consumption to an increased risk of breast cancer.
According the review, no conclusive evidence demonstrates whether the health benefits associated with drinking beer or wine are due to the alcohol (some studies indicate moderate alcohol consumption may stimulate the body to become stronger through a process known as hormesis). Similarly, there's no clear evidence that the benefits derive from other substances, particularly the antioxidant polyphenols found in these beverages.
In any case, one well-known benefit of drinking wine is an increase in HDL ("good") cholesterol. Flavonoids and other antioxidants in wine help protect the heart and blood vessels from the damaging effects of free radicals produced in the body. And resveratrol, an antioxidant in the skin of grapes, also contributes to the health benefits of red wine.
The health benefits of beer appear to come from a flavonoid called xanthohumol, which may also have antiviral, anti-allergic, anti-clotting, anti-inflammatory, and anti-tumor activity. Xanthohumol was first isolated in 1913 from hops, the aromatic herb that flavors beer. Studies at the Linus Pauling Institute at Oregon State University (OSU) have shown it to be active against breast, colon, and ovarian cancer cells - at least in test tubes. It might also help prevent prostate cancer.
Dark beer appears to be better for health than light beer because of its higher content of flavonoids. It also gives you more iron.
In general, alcohol doesn't seem to have an adverse effect on health unless you drink too much of it. Having more than one to two alcoholic drinks a day increases your intake of calories and may contribute to obesity. Excessive alcohol consumption can also raise your triglycerides (blood fats) and blood pressure, and can increase the risk of heart failure, stroke, cardiomyopathy (enlarged heart muscle due to disease), cardiac arrhythmia (an irregular heartbeat), as well as liver damage, certain types of cancer, accidents, and fetal alcohol syndrome (if you drink too much while pregnant).
The health benefits of moderate drinking are subtle, and it's certainly possible to be robustly healthy without consuming any alcohol. Consequently, if you don't drink, you certainly shouldn't start for health reasons.
Andrew Weil, M.D.