New findings from a team of American scientists point to underlying genetic factors as a probable explanation for co-occurring symptoms of bulimia and alcohol abuse/alcoholism in Caucasian-American and African-American women.
Current scientific evidence indicates that women affected by the eating disorder bulimia nervosa frequently develop diagnosable symptoms of alcohol use disorder (the modern term for alcoholism and alcohol abuse). In a study published in June 2015 in the journal Drug and Alcohol Dependence, a group of private and university-based researchers assessed the impact that genetic factors have on overlapping symptoms of bulimia and alcohol use disorder in American women with a Caucasian racial/ethnic background and American women with an African racial/ethnic background.
Bulimia nervosa is characterized by two main symptoms: periodic involvement in episodes of excessive or extreme food consumption and subsequent efforts to purge the consumed calories from the body. In any given individual, this binging-purging cycle may occur as often as multiple times each day or as seldom as once every few months. People with the condition typically feel unable to control their binging participation and attempt to purge food calories in response to feelings of self-loathing or self-disgust. Specific purging methods associated with bulimia include self-provoked vomiting, laxative misuse, diuretic misuse, enema misuse and extreme exercise.
Alcohol Use Disorder
Damaging symptoms found in people affected by alcohol addiction (i.e. alcohol dependence or alcoholism) can overlap to a considerable degree with the symptoms found in people affected by non-addicted alcohol abuse. Prior to 2013, doctors in the U.S. frequently faced the uncomfortable task of prioritizing the symptoms of one condition over the other in many of their patients. The alcohol use disorder diagnosis, introduced by the American Psychiatric Association in May 2013, is designed to recognize the overlapping nature of alcohol addiction and non-addicted alcohol abuse, and thereby give doctors a way to account for all alcohol-related symptoms instead of omitting some symptoms in favor of others. In its mildest form, the disorder encompasses two or three symptoms of alcoholism and/or alcohol abuse. In its moderate form, it encompasses four or five symptoms. Severe alcohol use disorder encompasses six or more symptoms of alcoholism and/or alcohol abuse.
Overlapping Symptoms in Women
Women with bulimia have a higher level of exposure to problematic substance use than women not dealing with an eating disorder. They also have a higher level of exposure to substance problems than women with anorexia nervosa or a third eating disorder called binge-eating disorder. Modern research points to an alcohol abuse history in almost one-third (31 percent) of all bulimic women. Among women hospitalized for eating disorder treatment, individuals with bulimia meet the criteria for an alcohol use disorder diagnosis roughly 100 percent more often than individuals with binge-eating disorder or anorexia.
Explanations for the Overlap
In the study published in Drug and Alcohol Dependence, researchers from Washington University in Saint Louis, the Yale University School of Medicine and private practice used data gathered from 3,781 participants in a long-term project called the Missouri Adolescent Twin Study to help determine if genetic factors can explain the degree of overlap between bulimia and alcohol use disorder in women. Three thousand two hundred and thirty-two of the participating women had a Caucasian-American racial/ethnic background, while the remaining 549 had an African-American racial/ethnic background. Twins were used because they give researchers the ability to determine the impact of genetics without resorting to extensive, prohibitively expensive genetic testing in large-scale studies.
The researchers concluded that roughly 59 percent of Caucasian-American and African-American women’s risks for alcohol use disorder are genetic. They also concluded that roughly 43 percent of Caucasian-American and African-American women’s risks for bulimic binging and purging are genetic. After analyzing the degree of overlap between the conditions, the researchers found that shared genetic risk is the only identifiable explanation for the frequency of alcohol use disorder in women with bulimia.
The study’s authors note that non-genetic environmental factors also affect women’s chances of developing bulimia and alcohol use disorder. However, they concluded that such factors vary considerably from person to person and do not sufficiently explain the degree of overlap between the two conditions. The authors believe they are one of the first research teams to demonstrate the shared genetic risks factors for bulimia and alcohol use disorder in women with different racial/ethnic ancestries.