Scientists Uncover a Major Biological Clue Behind Anorexia Relapse

3 min readNew research has uncovered a hormone linked to anorexia relapse.The hormone is tied to hunger cues.Experts say the findings could influence how patients are treated in the future.Up to 4 percent of women may experience the eating disorder anorexia nervosa in their lifetime. Anorexia can be deadly, and it can be difficult to overcome, as it has a high relapse rate. Some data suggest that up to half of people who are treated for anorexia nervosa will relapse within 10 years.Now, a Translational Psychiatry study highlights a hormone pathway that may explain why so many people with anorexia nervosa relapse. Researchers looked at the relationship between ghrelin (a hormone that usually signals to people when it’s time to eat) and LEAP2 (a naturally occurring protein that blocks ghrelin’s activity).The findings aren’t entirely new, but they “build on existing research in a meaningful way,” says Erin Birely, LCPC, a counselor who specializes in disordered eating and alumni services coordinator at The Renfrew Center. Experts also mention that this could lead to a potential treatment to help people with anorexia nervosa in the future. Here’s why.Meet the experts: Rebecca Boswell, PhD, director of the Princeton Center for Eating Disorders at Penn Medicine Princeton Health; and Erin Birely, LCPC, counselor and alumni services coordinator at The Renfrew Center.What did the study find?For the study, researchers followed 30 women between the ages of 18 and 60 who were diagnosed with anorexia nervosa. The participants took part in a four-month program at an eating disorders center where they went through refeeding treatment. (Refeeding is a process of gradually increasing the calorie intake of people who are malnourished.)As part of the study, the participants gave blood samples before and after their treatment, as well as again six months later. The researchers specifically looked at ghrelin levels. They discovered that patients had levels of a ghrelin antagonist called LEAP2 that were 20 percent higher when they were first hospitalized compared to four months later, when they had gained weight.Scientists found a link between the ratio of ghrelin to LEAP2 and impulse control after patients who had their weight restored—but only in those who were able to stick with a stable weight gain after they were discharged. On the other hand, LEAP2 levels went back up in people who relapsed. In a follow-up animal study, the researchers found that these hormonal shifts were linked with nutritional status.How does ghrelin impact relapse?There are likely a few things happening here. “In the absence of access to food, the brain adapts by not expecting as much reward from food,” says Rebecca Boswell, PhD, director of the Princeton Center for Eating Disorders at Penn Medicine Princeton Health. But people’s brains can re-learn that reward sensitivity through exposure to food, weight restoration, and treatment, she says.“These new findings highlight hormonal changes associated with this healing reward sensitization process associated with refeeding, including through ghrelin/LEAP2 pathways,” Boswell says.Changes in how ghrelin works in the body may be connected to patterns of thinking that have been linked with relapse risk, Birely says. “That doesn't mean ghrelin causes someone to relapse,” she says. “Recovery is influenced by many biological, psychological, and social factors that work together. Instead, these findings highlight another way the body and brain may remain closely connected throughout the recovery process.”What does this mean for future treatments?The findings could someday lead to the development of new biomarkers to determine treatment success during nutritional rehabilitation, Boswell says. “Instead of solely relying on weight as a treatment outcome, future work could allow us to consider the possibility of examining changes in hormonal (ghrelin/LEAP2 signaling) and cognitive function as indicators of treatment outcome and likelihood of long-term remission.”Boswell calls a reliable biomarker for eating disorder treatment success a “game changer,” especially because it could help to individualize care and move towards a more science-based, weight-inclusive treatment model.