Drugs to help stop smoking without gaining weight might not be far away. It should be possible to reduce one's food intake by activating the nicotinic receptors in hypothalamus - a brain center that controls feeding, scientists say.
It is well known that smoking suppresses appetite. Smokers are often thinner than nonsmokers and often gain weight when they quit smoking, which may keep some smokers from attempting to kick the habit.
Prior research shows that the average weight gain after smoking is less than 10 pounds, but fear of weight gain can prove discouraging.
In the study, published in the June 10 issue of Science, it was found that a nicotine-like drug, cytisine, specifically activated nicotinic receptors in the hypothalamus. This resulted in the activation of a circuit that reduced food intake and body fat in a mouse model. This effect was very specific, since a drug that prevented cytisine from binding to its hypothalamic receptors blocked the reduction in food intake.
Through the use of tobacco, nicotine is one of the most heavily used addictive drugs and the leading preventable cause of disease, disability, and death in the United States. According to the Centers for Disease Control and Prevention, cigarette smoking results in more than 440,000 preventable deaths each year — about 1 in 5 U.S. deaths overall. Despite the well-documented health costs of smoking, many smokers report great difficulty quitting.
"These mouse models allow us to explore the mechanisms through which nicotine acts in the brain to reduce food intake," said Dr. Marina Picciotto, of Yale University, New Haven, Conn. and senior author for the article. "We found that nicotine reduced eating and body fat through receptors implicated in nicotine aversion and withdrawal rather than reward and reinforcement."
"These results indicate that medications that specifically target this pathway could alleviate nicotine withdrawal as well as reduce the risk of overeating during smoking cessation," said Dr. Nora D. Volkow, Director of the National Institute on Drug Abuse (NIDA). "Although more research is warranted, such a highly selective compound might be more effective than drugs that act on more than one type of nicotinic receptor."