People with a family history of alcoholism, especially women, have an elevated risk of also becoming obese, according to a new study. And the link between the two appears to be strengthening — the risk of becoming obese, for people with alcoholics in their family, is higher now than in the past, the researchers said.
The researchers said a possible explanation for obesity in those with a family history of alcoholism is that some individuals may substitute one addiction for another.
After seeing a close relative deal with alcohol problems, a person may shy away from drinking, but high-calorie, hyper-palatable foods could stimulate the reward centers in their brains, and give them effects similar to what they might experience from alcohol, the researchers said.
"Ironically, people with alcoholism tend not to be obese," said study researcher Richard A. Grucza, an assistant professor of psychiatry at Washington University School of Medicine in St. Louis. "They tend to be malnourished, or at least under-nourished because many replace their food intake with alcohol."
Further, the study showed men and women with a family history of alcoholism were more likely to be obese in 2002 than members of that same high-risk group had been in 1992.
The rise in this risk over one decade indicates that some change in the environment, rather than in people’s genes, is at work, Grucza said.
Grucza said the environmental changes at work may be in the food we eat, and the fact that more of the foods that are available to us interact with the same brain areas as addictive drugs.
"Much of what we eat nowadays contains more calories than the food we ate in the 1970s and 1980s, but it also contains the sorts of calories — particularly a combination of sugar, salt and fat — that appeal to what are commonly called the reward centers in the brain," Grucza said.
This effect on the brain’s reward centers may be what obesity and the addictive behaviors seen in alcoholism have in common.
"Alcohol and drugs affect those same parts of the brain," Grucza said. Because the same brain structures are being stimulated, overconsumption of unhealthy foods might be greater in people with a predisposition to addiction.
Obesity in the United States has doubled in recent decades, from 15 percent of the population in the late 1970s to 33 percent in 2004, the researchers said. Obese people – those with a body mass index (BMI) of 30 or more – have an elevated risk for high blood pressure, diabetes, heart disease, stroke and certain cancers.
In 2001 and 2002, women with a family history of alcoholism were 49 percent more likely to be obese than those without a family history of alcoholism, the study showed. The researchers found a similar link between the conditions in men, but the effect was not as strong, they said.
The researchers analyzed data from two large alcoholism surveys from the last two decades: The National Longitudinal Alcohol Epidemiologic Survey was conducted in 1991 and 1992;The National Epidemiologic Survey on Alcohol and Related Conditions was conducted in 2001 and 2002. Almost 80,000 people took part in the two surveys.
The researchers examined other variables — such as smoking, alcohol intake, age and education levels — but none seemed to explain the association between alcoholism risk and obesity.
Grucza said the results suggest there should be more discussions between alcohol and addiction researchers and those who study obesity. He said there may be some people for whom treating one of those disorders also might aid the other.
The study is published in the December issue of the journal Archives of General Psychiatry.
Pass it on: People with a family history of alcoholism may be more likely than others to become obese.
Follow MyHealthNewsDaily on Twitter @MyHealth_MHND.
Live Science newsletter
Stay up to date on the latest science news by signing up for our Essentials newsletter.