First some background: According to the National Institute of Mental Health (NIMH), an estimated 0.5 to 3.7 percent of females in the United States suffer from anorexia nervosa in their lifetime, and an additional 1.1 to 4.2 percent of females suffer from bulimia nervosa in their lifetime. When figured into the US Census Bureau’s most recent population statistics, this means that as many as 5.7 million females will suffer from anorexia and as many as 6.5 million females will suffer from bulimia at some point in their lifetime. Now some people may dismiss anorexia or bulimia nervosa as simply a mental disorder that has no real effect on a person’s life other than how they view themselves and food, but according to the NIMH, the mortality rate among those with anorexia nervosa is approximately 5.6% per decade, which is 12 times higher than the death rate among females ages 15-24.
The new information: The study looked at 134 patients with anorexia nervosa, 180 patients with bulimia nervosa, and 148 healthy individuals, and was looking for two specific mutations in endocannabinoid genes, a mutation in the gene coding for cannabinoid receptor 1, and a mutation in the gene coding for FAAH (fatty acid amide hydrolase), which is the enzyme in our bodies that degrades cannabinoids. It was found that compared to the healthy individuals, anorexic and bulimic patients were significantly more likely to have mutations in cannabinoid receptor 1 gene or mutations in the FAAH gene. Additionally, compared to the healthy individuals, it was much more likely that anorexic patients had mutations in both genes.
What this means: This experiment tells us that there may in fact be a genetic predisposition to anorexia nervosa and bulimia nervosa. Additionally, cannabinoids may be used in the treatment of these two eating disorders as the genetic mutations cause a decreased sensitivity to them.
Monteleone, P., et al. “Association of CNR1 and FAAH endocannabinoid gene polymorphisms with anorexia nervosa and bulimia nervosa: evidence for synergistic effects.” Genes, brain, and behavior. 8.7 (2009): 728-32.