It is well known that drinking alcohol is more harmful to women than it is to men, but new research delves deeper into this imbalance among genders. When women drink, they become intoxicated more quickly than men do, and the alcohol causes more damage. Sharon Wilsnack, a professor of neuroscience at the University of North Dakota School of Medicine whose research includes a 20-year study of women and alcohol, says that the differences are more complex than women being generally smaller than men. There are two things at work, Wilsnack says. The first is an enzyme called alcohol dehydrogenase that processes alcohol in human stomachs. Women don\u2019t have as much of the enzyme as men do, so more alcohol passes through the female\u2019s bloodstream. The second factor is water, which dilutes the alcohol once it is in the system. Women\u2019s bodies contain less water than men\u2019s, partly because women are smaller and partly because women have more fatty tissue, which doesn\u2019t have as much water as muscle. Even if a woman is exactly the same size as the man she is drinking with, she is likely to become more intoxicated if she consumes the same number of drinks as the man does. Women have lower body weight, less body water, and less of the enzyme that breaks alcohol down, \u009dWilsnack says. So they have significantly higher alcohol concentrations in the blood, and that\u2019s going to the brain, liver, heart, and other organs. \u009d Anne Brockhoff of KansasCity.com writes that this is why moderate drinking is defined as one a day for women, compared to two for men. The federal government\u2019s Dietary Guidelines for Americans defines one drink as 1.5 ounces of 80-proof spirits, 12 ounces of regular beer, or 5 ounces of wine. About 60 percent of American women drink and 13 percent of those exceed the one-a-day recommendation, according to the National Institute on Alcohol Abuse and Alcoholism. About 5.3 million women drink in a way that threatens their health, safety, and general well-being, the institute says. Women who drink, especially those who drink heavily, are at greater risk for all sorts of problems, including liver disease and different forms of cancer. According to the alcoholism institute, as little as one drink a day can slightly raise your risk of breast cancer, especially if you are postmenopausal or have a family history of breast cancer. Moderate drinking has been shown to help lower the risk of coronary heart disease, especially in women older than 55, but long-term, heavy drinking is a leading cause of cardiovascular disease, the institute says. Because alcohol impairs your judgment, it also puts women at greater risk for drunken driving, violence, and sexual assault, among other things. Some researchers also say women are more likely to become addicted to alcohol than men. Heavy drinking can also impair fertility, and drinking while pregnant can lead to a range of birth defects. Nursing mothers should also be cautious, because alcohol does pass into breast milk. (A new product called Milkscreen helps detect the presence of alcohol in breast milk.) Natalie Bovis-Nelsen, a spirits expert and author of Preggatinis, says that women should not try to keep up with the boys. She also warns that women shouldn\u2019t be taken in by movies and celebrities that glamorize excessive drinking, and should watch out for oversized cocktails and bottle service that requires the purchase of whole bottles of spirits. We can enjoy the glamour of cocktail culture, but in moderation and in keeping with what we know about health, fitness, and overall well-being in the modern world, Bovis-Nelson says. She personally alternates cocktails with nonalcoholic drinks on her nights out and makes marathon training a part of her weekly routine. Knowing yourself is also important, Wilsnack says. Are you at risk for breast cancer? Heart disease? Alcoholism? Trying to get pregnant? Planning to drive home? Then drink, or don\u2019t drink, accordingly.