Racial differences found in genetic and environmental influences on problem drinking

The environment in which African-American girls are raised tends to protect them against problem use of alcohol, shows a new Yale University study of more than 3,500 twins. By contrast, familial environmental factors tend to significantly increase problem use of alcohol in girls of European descent, according to the study published June 13 in the journal Alcoholism: Clinical and Experimental Research.

African Americans tend to have lower rates of alcohol-related problems than individuals of European descent, but it has been unclear why. The twin study helps researchers tease out how much of the risk of alcohol abuse is inherited and how environmental factors contribute.  The inclusion of both African Americans and European Americans in the study allowed the researchers to compare the relative impact of genes vs. environment across the two racial groups.

“Environmental influences shared by family members such as parenting and neighborhood do not contribute significantly to problem alcohol use in African-American adolescents and young women, but they play a substantial role in those of European descent,” said Carolyn Sartor, assistant professor of psychiatry at the Yale School of Medicine and first author of the paper. “For African-American girls and young women, problem drinking can be explained by a combination of genes and environmental factors that are not shared by family members.”

The study did not directly measure specific environmental factors that may be protective for African-American girls. Culturally more conservative views on use of alcohol and stronger parental disapproval of alcohol in the African-American community as well as higher church attendance may play roles, says Sartor.

The study of twins suggests genetics are more likely to explain cases of problem drinking in adolescents and young women of African-American descent than those of European descent, say the scientists.

The study was funded by grants from the National Institute on Alcohol Abuse and Alcoholism and the National Institute of Child Health and Human Development.

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