CU: Anorexics, obese react to taste differently

Posted at 1:50 AM, May 17, 2016

How you eat can change your brain.

In a recent study of 106 women suffering from anorexia nervosa or dealing with obesity, researchers at the University of Colorado Anschutz Medical Campus found that both groups responded differently to taste, when compared with the control group.

The study’s lead author, Dr. Guido Frank, a psychiatrist and associate professor at the CU School of Medicine, said participants underwent brain imaging, while tasting sugar water or plain water. 

Researchers then studied a specific part of the brain, the insula, the brain’s primary taste cortex, to find out if abnormal eating patterns were associated with changes in the insula's ability to classify taste stimuli.

“The brain scans measure blood flow,” Frank said, while pointing to several insula images on his computer screen. “This one shows a woman with anorexia nervosa who has low classification.”

In other words, she couldn’t distinguish between the regular and the sweetened water.

“If you can’t differentiate between tastes, that could impact how much you eat,” he said. “That could also activate or not activate brain reward circuits.”

Dr. Frank said it was the same for women who were obese.

“What we believe,” he said, “is that in anorexia nervosa, the brain is sensitive, overly sensitive, to any type of taste stimuli.  In obesity, we believe that the brain is under sensitive to any type of taste stimuli.”

He said the findings could eventually lead to new treatments for eating disorders.

“We might be able to devise a treatment that includes making food more bland,” he said, less stimulating for people with anorexia nervosa and maybe more intense for individuals with obesity,” Frank said.

The study is being hailed by representatives of the Eating Disorder Foundation.

“I think what this really shows is that if there’s someone with an eating disorder, they could be born with it, that it’s not something that’s their fault,” said Melissa Preston, a licensed professional counselor and registered dietician who volunteers with the foundation.

Preston said the study could have far reaching implications, especially for those engaged in “binge-eating,” or those dealing with anorexia.  She said anorexics experience a “high” from not eating.

“It’s very difficult to wrap our brains around that,” she said, “but it’s the truth.  It feels very good to them to not eat.”

Preston told Denver7 that an estimated 30-million Americans are dealing with eating disorders.

Despite the prevalence of eating disorders, the National Institutes of Health provides comparatively little funding for eating disorder research.

Comparison from National Eating Disorders Association

Illness                                            Prevalence                    NIH Research Funds (2011)
Alzheimer’s Disease                        5.1 million                     $450,000,000
Autism                                                3.6 million                     $160,000,000
Schizophrenia                                  3.4 million                     $276,000,000
Eating disorders                               30 million                      $28,000,000

CU researchers also found that if you’ve engaged in a great deal of under-eating or over-eating, it makes it harder to go back to normal eating.

“It’s important to note,” Frank said, “that if you return to a normal weight and if you return to normal eating, your brain normalizes.”

He said he’d like to expand on the research.

“Aside from the insula, what other parts of the brain are involved in this circuitry,” Frank said.  “We want to expand it across a larger group of individuals, across all eating disorders.”