Researchers found the hormone estrogen could trigger brain serotonin neurons to inhibit binge eating in female mice.
Past research has shown women who have irregular menstrual cycles are more likely to binge eat, suggesting hormones play a role in this behavior, Baylor College of Medicine reported.
"Previous data has also shown that in humans, there is a strong association between estrogen and binge eating. When estrogen is high, binge eating is inhibited, but when estrogen is low, binge eating becomes more frequent. Using mouse models, we set out to see what the effects of estrogen were on binge behavior in female mice," said Doctor Yong Xu, assistant professor of pediatrics and senior author of the paper.
In the study the team first realized the link between estrogen and binge eating in mice, and found the same results to be true in humans.
"We can speculate that in women who develop binge eating who also happen to haveirregular menstrual cycles, it is probably because their estrogen function is somehow damaged, which is what leads to the development of binge eating," Xu said.
The team went on to determine what receptor was mediating the estrogen effect on binge eating; using a mouse model the team linked receptor-α to the phenomenon. When expressed by serotonin neurons it mediates the effect of estrogen and reduces binge eating.
Around the same time as this finding was made researchers at Indiana University discovered a compound called GLP-1-estrogen, which could carry estrogen and deliver to certain receptors for delivery. The compounds was found to be good for body weight control. They found did not increase the risk of breast cancer as many common therapies do because it does not deliver estrogen to breast tissue.
The team found when a systematic injection of the compound was given to the mice there was an increase in estrogen activity in the serotonin, meaning it can deliver estrogen to where binge eating is regulated. They also showed the compounds inhibits binge eating in mice; part of the success comes from estrogen and part comes from GLP-1.
"There are a few studies showing that binge patients tend to have decreased GLP-1 in their blood, but nobody had shown that GLP-1 suppresses binge eating in animals or humans until now," Xu said. "We showed that these two things, estrogen and GLP-1, work together to decrease binge eating and that GLP-1 can carry estrogen to this specific site to produce a benefit, but bypasses the breast tissue."
