Different brain activity for people with eating disorders
By Margaret Rogers
New research has been conducted to gain a better understanding and treatment of eating disorders. It has found that the brains of individuals with anorexia and those with obesity are wired differently.
Led by Laura Holsen of Harvard Medical School and Brigham and Women’s Hospital, a team of researchers used fMRI brain imaging to look at the brains of people in three different eating groups – anorexia nervosa, simple obesity and Prader-Willi syndrome (extreme obesity). They also examined the images of healthy individuals.
It was found that a there is a variety of brain activity across a wide spectrum of eating behaviours. This varies from extreme over-eating through to food deprivation. These differences influence the development of eating disorders and the way individuals respond to weight loss programmes.
Of all mental illnesses, it is eating disorders that have the highest mortality rate. In America more than two-thirds of the population are currently over-weight or obese. This is causing great concern as it is being over-weight or obese that is a health factor with a risk of diabetes, cancer and cardiovascular disorders.
Laura Martin, PhD., one of the research team said ‘This body of work not only increases our understanding of the relationship between food and brain function but can also inform weight loss programmes. One of the most intriguing aspects of these studies of the brain on food, is they show consistent activations of reward areas of the brain that are also implicated in studies of addiction.’
The imaging showed that individuals with anorexia, when hungry, displayed a substantially decreased response to various pictures of food in the regions of their brains that is associated with reward and pleasure. In the images of those who seriously over-eat there was a significant increase in response in the same regions of the brain.
Holsen says ‘Our findings provide evidence of an overall continuum relating food intake behaviour and weight outcomes to food reward circuitry activity. Even in individuals who do not have eating disorders, there are areas of the brain that assist in evaluating the reward value of different foods, which in turn plays a role in the decisions we make about which foods to eat. ‘