How Disordered Eating Can Impact Brain Health, According to Science

These changes are stark but can be reversed if you follow this expert guidance.

a brain and a spoon and fork
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Nearly 1 in 10 Americans have been or will be diagnosed with an eating disorder, according to the National Association of Anorexia Nervosa and Associated Disorders. While all forms of eating disorders—including bulimia, binge eating disorder, anorexia and orthorexia—impact the body and brain in different ways, research published in 2022 proves that anorexia nervosa, in particular, might have a surprisingly strong impact on not only the psychology of the brain but the physiology of it as well.

According to a May 2022 study in the journal Biological Psychiatry, individuals with severe anorexia have "sizable reductions" in three important parts of the brain: cortical thickness, subcortical volumes and cortical surface area. These shrinking spots hint at the loss of brain cells or a lack of connection between these brain regions.

What This Brain Health Study Found

By analyzing the results of nearly 2,000 brain scans of people with anorexia, those in recovery from anorexia and "healthy controls" with no eating disorder history, U.K. neuroscientists found a substantial link between brain size and shape and anorexia. Other studies have linked binge eating disorder, bulimia and obesity to some shifts in brain structure as well, but those with anorexia had reductions in brain shape and size twice to four times as large as those with other mental health conditions, including obsessive-compulsive disorder (OCD) and attention-deficit/hyperactivity disorder (ADHD).

"The effects of anorexia nervosa have been largely focused on the physical effects of severe calorie restriction. But this study shows us that its impact on the body may decrease the size, and likely the amount of nerve cells in certain parts of the brain in just five years," explains Ralph Esposito, N.D., a Greenwich, Connecticut-based naturopathic physician and scientific advisor to Athletic Greens. "This can impact cognitive function in those with anorexia nervosa, including their ability to identify and respond safely to the environment and their ability to focus."

When our brain changes, it can make it harder to think, decide things, make plans and move ahead with a decision. This study found that living with anorexia for 1 to 13 years, depending on the individual's age and the extent of restriction, is enough to alter the brain.

"People get 'stuck' in rigid thinking and ways of doing things because their brain doesn't have enough nourishment to be flexible in its thinking," adds Jillian Lampert, Ph.D., M.P.H., RD, LD, FAED, chief strategy officer of Accanto Health in St. Paul, Minnesota.

The other symptoms of these brain adjustments may vary but might include challenges with spatial awareness, proprioception and attention or focus. Individuals may have difficulty performing some physical actions in response to the environment or even feeling stable on their feet, Esposito says.

While this sounds stark, the researchers found that these cranial changes aren't always permanent.

"We found that the large reductions in brain structure, which we observed in patients, were less noticeable in patients already on the path to recovery. This is a good sign because it indicates that these changes might not be permanent. With the right treatment, the brain might be able to bounce back," Esther Walton, Ph.D., lead researcher and lecturer in the Department of Psychology at the University of Bath, tells University of Bath Communications.

How Individuals with (or Recovering from) Anorexia Can Protect Their Brains

Seeking treatment ASAP is the most important course of action, the research team agrees. The path to recovery often includes cognitive behavioral therapy, medication and, most crucially, weight gain. The aforementioned brain structure changes might be reversible, particularly the earlier they are reversed.

"With anorexia, which is characterized by inadequate nutritional intake, the semi-starvation results in people losing weight, decreasing muscle and bone mass, experiencing dehydration and losing tissue mass of other structures, like the brain," Lampert says. "The body loses water, fat, muscle and tissue when it's experiencing deprivation, like plants lose leaves when they aren't watered enough. The loss of nutrition means the body has to conserve all the energy it can and get nutrition anywhere else it can, like bone, muscle and stored water. Basically, all of our stores get used up and our brain experiences a change in mass."

Just like what happens when you water and nourish a plant—the leaves rebound, new ones grow, leaves that weren't completely dry bounce back and the plant is healthy again—the same thing can happen when people with anorexia are renourished, Lampert adds. ICYMI, here are eight things that can happen to your body when you skip meals.

"Thankfully, the study suggests these changes are not permanent and can be reversed with renutrition. But we don't know what this does to their risk for brain and mental health-related disorders as they age," Esposito says.

"Renourishment," the cornerstone of eating disorder treatment, gets people back to health by restoring hydration, bone health and tissue health. A September 2021 study in the Journal of Eating Disorders found that almost all of the structural changes in the brain, due to anorexia, can be resolved with the proper treatment and a healthy weight.

"People with severe anorexia can recover after years of being ill and have a quality life with a normal relationship with food and their bodies, a healthy weight and very slim chances that their brain is impacted long-term," Lampert says. "Nutrition is the key—without it, there isn't a way for the brain to get the fuel it needs to function. Recovery is possible at any stage of illness, and early detection and treatment is best. If you are concerned about yourself or someone else, reach out for professional help. Don't wait!"

If you or a loved one are coping with an eating disorder, contact the National Eating Disorders Association (NEDA) Helpline for support at 1-800-931-2237.

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