by -- Robert Preidt
Updated: Feb 10th 2010

 

WEDNESDAY, Feb. 10 (HealthDay News) -- People with the eating disorder anorexia nervosa have excess levels of fat in their bone marrow, U.S. researchers have found.

The disorder, which affects mainly young women, leads to extremely low body weight and an obsessive fear of weight gain.

"It's counterintuitive that an emaciated young woman with almost no subcutaneous [below the skin] fat would be storing fat in her marrow," lead researcher Dr. Catherine Gordon, an endocrinologist and director of the Bone Health Program at Children's Hospital Boston, said in a hospital news release.

For the study, MRI scans were taken of the knees of 40 girls, who averaged 16 years old -- 20 with anorexia and 20 who were healthy. The girls with anorexia had higher fat content and less than half as much healthy red marrow in their knees, the researchers found. The difference was also seen in the lower thighbone and upper shinbone.

The findings are published in the February issue of the Journal of Bone and Mineral Research.

Earlier studies had found that hormonal changes in malnourished people trigger the bone marrow's mesenchymal stem cells to turn into fat cells rather than bone-forming cells. That could explain why people with anorexia lose bone mass and sometimes develop osteoporosis, the researchers said.

"Bone formation is very low in girls with anorexia, and that's a particular problem because they are growing adolescents who should be maximally forming bones," Gordon said. "But because of the hormonal alterations induced by malnutrition, the bone marrow stops yielding the needed cells to form bone. Instead, the stem cells are pushed toward fat formation."

Gordon plans further studies to find out why this occurs. One theory is that it's due to the body's attempt to store energy and preserve warmth. Because of their lack of insulating fat, people with anorexia often develop extremely low body temperatures (hypothermia) and need to be hospitalized.

More information

The U.S. National Women's Health Information Center has more about anorexia nervosa.

Nicole Richie: ‘Anorexia Rumors Were Insulting’

NICOLE Richie has spoken out to debunk claims she had anorexia.

The reality TV star insists accusations she suffered with an eating disorder were completely untrue.

“It was a little unfair to say someone has an eating disorder when they don’t,” the 28-year-old mother of two told Marie Claire.

“It’s extremely insulting and irresponsible. An eating disorder is serious and it’s a disease.”

The National Enquirer recently claimed that Richie has vowed to boost the health of two of her closest friends — actress Mischa Barton and celeb stylist Rachel Zoe.

“Nicole has battled weight issues, but finally figured out how to balance her life, and is determined to lead Mischa and Rachel to a happier and healthier lifestyle,” an insider said.

“Mischa has been down lately because her career has been in limbo, and rather than returning to the party scene, she has turned to food.

“Mischa’s career has been foundering. Her last series The Beautiful Life was canceled – and she’s been eating everything in sight for solace.

“Tiny Rachel is at the other end of the spectrum. She works so hard dressing her A-list actress clients that she literally forgets to eat.

“Nicole has stepped in and had one-on-one interventions with Mischa and Rachel.

“She’s counseled both on a healthier way of life and how to incorporate nutritious organic food into the stress-filled schedule of a celebrity.

“Nicole overcame her body-image and substance-abuse problems and she wants to help her friends Mischa and Rachel have the same success.”