Eating disorders and alcoholism may share genetic risk factors according to new research published in the Journal of Studies on Alcohol and Drugs. This is especially true of binge eating and purging.
“Prior studies have shown that among people who had eating disorders, there were higher rates of alcohol abuse and dependence than those who didn’t have these eating disorders,” study author Melissa Munn-Chernoff, Ph.D., of Washington University School of Medicine in St. Louis, said.
To gain a better understanding of the underlying connection between the disorders, Munn-Chernoff and her team analyzed data from nearly 6,000 twins—both identical and fraternal. Identical twins share all of the same genes, while fraternal twins only share about half, making them genetically similar to siblings who aren’t twins.
The researchers conducted a series of interviews to determine the participants’ alcohol and eating habits. They found that nearly 25 percent of men and 6 percent of women studied had been alcohol dependent at some point in their lives, and 11 percent of men and 13 percent of women had experienced problems with binge eating. Fourteen percent of women also admitted to using two or more purging tactics. Researchers then compared the twins to one another.
According to their statistical computation, the researchers found that genetics play an important role in the development of any of these disorders, explaining 38 percent to 53 percent of a person’s risk. The same genetic risk factors for alcoholism seemed to make people vulnerable to binging and purging as well.
Dr. Munn-Chernoff noted that a person’s environment still influences a person’s risk for alcoholism or bulimia. “These types of studies capture the nature and nurture debate,” she said. “It’s always a combination of both, but these studies are designed to tap into that, and even though we didn’t find significant environmental risk factors, it doesn’t mean that they’re not important.”
Dr. Munn-Chernoff hopes the study will encourage doctors to associate alcoholism with bulimia. She said that if a patient presents the symptoms for one of these disorders, his or her doctor should look for symptoms of the other disorder.