Submitted by Denise Reynolds RD on 2010-12-31
We all know that weight gain occurs from the consumption of calories over what the body needs and/or lack of enough physical activity to burn the calories we do eat. But the reasons behind why we overeat are much more complex. Researchers are actively studying genetics and other factors that contribute to our obesity epidemic. One such area of study involves the brain, and our seemingly addictive behavior toward certain foods.
Food addiction is not a new area of study, but it is not yet well understood. Previous research from the Scripps Research Institute found that certain high calorie foods trigger an addiction-like response in the brains of laboratory rats, leading the animals to become compulsive eaters.
Addiction researchers at Washington University School of Medicine in St. Louis seem to have found a similar link between alcoholism and obesity risk.
“In addiction research, we often look at what we call cross-heritability, which addresses the question of whether the predisposition to one condition also might contribute to other conditions,” says study first author Richard A. Grucza PhD. “This new study demonstrates a cross-heritability between alcoholism and obesity.”
Grucza and his team analyzed data from two large national surveys on alcoholism – The National Longitudinal Alcohol Epidemiologic Survey first conducted in 1991-1992 and repeated in 2001-2002. Almost 80,000 people took part in both surveys.
Both men and women who had a family history of alcoholism were more likely to be obese in 2002 than members of the same high-risk group in 1992. Women in particular were 49% more likely to be obese than those without a family history of alcoholism, says Dr. Grucza. The reason – People with predisposition to addiction are more likely to over consume foods that are high in calories, salt and fat because they stimulate the same structures in the brain as alcohol and drugs.
University of North Carolina researchers published a paper in 2003 with a similar finding. Dr. Todd Thiele, a professor in the Department of Psychology and the Bowles Center for Alcohol Studies, explored the role of a group of signaling proteins called melanocortins in laboratory animals. These seem to be associated with both overconsumption of alcohol and eating too much food.
Dr. Grucza does not discount environment’s influence on obesity. “The environment has changed between the 1990’s and the 2000’s.” He says that today, we consume more high-calorie, hyper-palatable foods in part because they are more readily available.