We know alcoholism runs in families — children with alcoholic parents have quadruple the risk of developing a drinking problem later in life than those without — but is the link genetic or the result of other influences?
According to a Feb. 8 Wall Street Journal article outlining the evidence for “alcoholism genes,” it is probably both.
Researchers from the Collaborative Study on the Genetics of Alcoholism, a 22-year National Institute on Alcohol Abuse and Alcoholism (NIAAA) investigation into the relationship between DNA and alcoholism, have put together compelling evidence from family studies indicating the problem has roots in nature versus nurture.
For instance, boys born to alcoholic fathers are nine times more likely to develop a drinking problem. Children with an alcoholic birth parent who are adopted in infancy have almost the same risk for alcoholism as they would have had they been raised by that parent.
Studies in specific ethnic groups also support a genetic link, according to David Goldman, M.D., chief of the Laboratory of Neurogenetics at NIAAA and the study’s senior investigator. About 40 percent of East Asians have a gene variation that causes reddening of the skin, increased heart beat, and nausea after drinking — aptly called “Asian flush.” These symptoms are a strong deterrent to drinking.
Conversely, a gene variation found almost exclusively in Finnish people has been linked to severe impulsivity. “Almost all these severely impulsive individuals [were] also alcoholic,” said Goldman. “And their worse impulsive problems occurred while they were drunk.”
Although the identification of a relationship between specific genes and alcoholism has spurred promising new therapies that target them, the investigators caution that it’s unlikely genetics will provide all the answers.
“All too often, you read that they’ve found a gene for this and a gene for that, and it’s very rarely that simple,” said Howard Edenberg, Ph.D., Chancellor’s Professor of Biochemistry and Molecular Biology at Indiana University and one of the study’s principal investigators.
“With a disease like alcoholism, where dozens or hundreds of genes could have a small impact, to find any one of them in the size of the studies we are doing, you have to be sort of lucky,” he said. “And the chance that the next group will be lucky is not that high.”
Social, cultural, and environmental influences muddy the causal relationship even further. Not everyone with an alcoholic parent or a genetic variation associated with alcoholism becomes an alcoholic. According to Edenberg, DNA is not destiny where human behavior is concerned.
“You can carry all kinds of genes,” he concluded. “If you manage to push away the glass or the bottle, you won’t have an alcoholism problem.”