Study Finds Link Between Family History of Alcoholism and Risk of Obesity
Richard A. Grucza, PhD., first author of the study, said that in addiction research, scientists often look at cross-heritability, which looks at whether the predisposition to one condition might also contribute to the predisposition for other conditions. For example, those who are at risk of developing alcoholism are also at risk of developing a drug addiction. Grucza added that this new study shows a cross-heritability between alcoholism and obesity, but also suggests that some of the risks are due to the environment, as it has greatly changed between the 1990s and the 2000s.
In the late 1970s, 15 percent of the population in the United States was obese. That percentage rose to 33 percent in 2004. Obesity carries a risk of high blood pressure, diabetes, heart disease, stroke, and cancer.
Grucza and colleagues said that those with a family history of alcoholism, especially women, have a growing risk of becoming obese. This may be due to changes in the type of food we eat and the greater availability of foods that interact the same regions of the brain that are activated by addictive drugs.
Grucza, an assistant professor of psychiatry, said that much of the food we eat now has more calories than food in the 1970s and 1980s, but it also contains a combination of sugar, salt, and fat that appeals to the brain’s “reward” center, the area of the brain that is also affected by alcohol and drugs. The researchers think that because the same brain regions are being activated, people who are predisposed to addiction may be over-consuming some of these foods, which can lead to obesity.
For the study, the researchers examined data from two large surveys on alcoholism from the last 20 years, which included almost 80,000 people. Gruzca said they looked family history of alcoholism and found that in 2001 and 2002, women with a family history of alcoholism were 49 percent more likely to be obese than those without the history. There was also an association among men, but it was more prominent in women.
Gruzca said a possible explanation for the association between alcoholism and obesity is that some people may substitute one addiction for the other. If someone has seen a family member be affected by alcoholism, he or she might avoid drinking but could replace the behavior with eating high-calorie, high-sugar foods that offer a similar reward.
He added that ironically, people with alcoholism tend to be malnourished, possibly because they replace their food intake with alcohol. Smoking and drinking, along with other factors like age and education level, didn’t seem to explain the association between family history of alcoholism and obesity. This suggests that the reason behind the association is at least partially environmental.
Gruzca concluded that the study suggests that there should be more cross-research between addiction and obesity studies, as treatment for one disorder could also help treat the other.
Source: Science Daily, Risk for Alcoholism Linked to Obesity, December 31, 2010