Women have approximately 10% more fatty tissue and less body water than men. This means that women attain a higher blood alcohol concentration (BAC) than men for the same volume of alcohol consumed.
Women have lower levels of alcohol dehydrogenase (ADH), an enzyme involved in the metabolism of alcohol. As a result, women experience the effects of alcohol more quickly, and for longer, than men.
On average, women weigh less than men and, therefore, have less tissue to absorb alcohol.
Women’s hormone levels fluctuate during the menstrual cycle and this may affect the rate of alcohol metabolism in the body, causing women to experience higher blood alcohol levels at different points in the cycle.
Although men and women experience many of the same negative physical effects of excessive alcohol intake, research indicates that, as well as the harm caused to women and the foetus in pregnancy, women may be more vulnerable to harm than men, and some risks are specific to women:
Although many studies have identified alcohol consumption as a risk factor for breast cancer, the biological mechanisms involved have not been defined. The international Collaborative Group on Hormonal Factors in Breast Cancer compared 58,515 women with breast cancer and 95,067 without it. It concluded that up to 4% of breast cancers in the developed world can be attributed to alcohol and that women drinking six drinks per day, on average, are 46% more likely to develop breast cancer.
Women develop liver disease at lower drinking levels and after shorter periods of time, compared to men. They are also more likely to develop alcoholic hepatitis and to die from cirrhosis of the liver.
Women may be more vulnerable than men to alcohol-induced brain damage. Views of the brain using magnetic resonance imaging found that a region of the brain involved in coordinating multiple brain functions was smaller in alcoholic women than non-alcoholic women and men.
There is some evidence to suggest that women who drink heavily may be more vulnerable to cognitive impairment than men, and this may have implications for spatial memory, attention and constructive thinking.
Alcohol intake correlates with decreased conception rates. Chronic drinking can result in inadequate functioning of the ovaries and sometimes cessation in menstruation. According to a study on the effect of moderate drinking on fertility, even women with a weekly alcohol intake of five or fewer drinks experienced reduced fertility. Couples trying to conceive may consider not drinking alcohol as it may affect the quality of the egg and sperm prior to conception.
Contraceptives delay the absorption of alcohol into the bloodstream; therefore, women taking oral contraceptives may not become intoxicated as quickly as they would normally.
Osteoporosis is a debilitating bone thinning disorder where bones become fragile and more susceptible to fracture, affecting more women than men. Studies have indicated that heavy drinking, particularly in adolescence or young adult years, can dramatically compromise bone quality and may increase osteoporosis risk in later life. Further evidence suggests that bones do not overcome the damaging effects when alcohol use is discontinued.