Researchers looked at nearly 6,000 adult fraternal and identical twins in Australia. Of those, nearly 25 percent of men and 6 percent of women were alcoholics, nearly 11 percent of men and 13 percent of women reported binge eating, and about 14 percent of women reported purging tactics such as self-induced vomiting or laxative abuse.
Genes appeared to account for 38 percent to 53 percent of the risk of developing these conditions, and some of the same genetic risk factors that make people susceptible to alcoholism also make them vulnerable to binge eating or purging, according to the study in the September issue of the Journal of Studies on Alcohol and Drugs.
The findings support "the idea that there are common genetic factors contributing to alcohol dependence and these eating disorder symptoms," lead researcher Melissa Munn-Chernoff, of Washington University School of Medicine in St. Louis, said in a journal news release.
Learning more about genetic and other risk factors may lead to better treatments for these disorders, she noted.
Previous studies found that women who binge eat or purge have higher-than-average rates of alcohol use disorders, but it wasn't clear if the disorders had genetic risk factors in common. While this new study indicates that this is the case, it's not clear exactly which genes are involved.
"We need to be aware that these problems can occur together, in both men and women," Munn-Chernoff said.
She suggested that when doctors see patients with a drinking problem, they may want to ask about binge eating and purging symptoms, or vice versa. Currently, that is something that is not routinely done.
The U.S. National Institute of Mental Health has more about eating disorders.