Gender Differences Affecting Alcohol Dependence

Alcohol dependence is caused by a number of factors, including genetics, environment and personal experience. Scientists know that men and women struggle with alcohol dependence at different rates, but understanding the cause of the difference has been difficult – that is, until the results of a recent study provided new clues about the way men and women differ in genetic responses to alcohol.

Polymorphisms of alcohol dehydrogenase-1B (ADH1B) and aldehyde dehydrogenase-2 (ALDH2) are strong genetic determinants for alcohol dependence. A recent study conducted at the Kurihama Alcoholism Center in Japan analyzed gender differences in the effects of these polymorphisms in how alcohol dependence develops. Researchers found that inactive ALDH2 can accelerate the path of alcohol dependence in women.

The study’s results will be printed in the November 2011 issue of Alcoholism: Clinical and Experimental Research, but they are currently available at Early View.

While alcohol dependence is more common among males than females, females are more likely to have co-existing psychiatric disorders than male patients, explained Mitsuru Kimura, chief scientist in the department of psychiatry at the Kurihama Alcoholism Center.

When a person drinks alcohol, a lack of ALDH2 causes a “flushing response” which includes flushing, nausea and a headache after consuming alcohol. The effect is a curbing of alcohol consumption. While ADH is important for metabolizing ethanol into acetaldehyde, ALDH is important for metabolizing acetaldehyde into acetate and water.

Kimura and colleagues performed genotyping of ALDH2 and ADH1B for 615 individuals hospitalized for alcohol dependence in the Kurihama Alcoholism Center. The participants consisted of 415 men and 200 women. The researchers also gathered clinical information and background data through chart reviews.

The results of the analysis showed that ALDH2 polymorphisms influenced the development of alcohol dependence differently between men and women. Though females cannot drink as much as males due to body size, the findings suggested that differences in alcohol metabolism related to genetic factors may have a significant effect on the morbidity differences between men and women, apart from their drinking habits.

The researchers also found that the flushing experience caused by inactive ALDH2 suppresses alcohol consumption, but women who have co-existing psychiatric disorders may drink heavily to cope with the symptoms of psychiatric disorders. This suggests a gene-gender interaction in the development of alcohol dependence.

The findings are important in understanding the effects that specific genes can have on the development of alcohol dependence, but also provides clues to gender differences in the evolution of alcohol dependence.