14 DAY TRIAL // Very often, former smokers complain about gaining weight. Unconsciously, they associate smoking with being thin, and have more incentives to pick up the habit again. But soon, new drugs may prevent this from happening, by acting on a new class of receptors that bind to nicotine.
A specific subclass of nicotine receptors in the human brain is responsible for prompting the body to reduce its food intake while smoking. When people quit, these receptors no longer send the inhibitory signals, allowing the brain to ask for more food.
People then begin to eat a lot more, increasing their risk of becoming overweight or obese. But experts now say that this may soon be fixed. By targeting the recently-discovered class of receptors, they have opened the way for the creation of new class of drugs.
These chemicals could act on the nicotine receptors even as people stop smoking. Food cravings would continue to remain low, as if people were still smoking, while the actual habit will be long gone. A gradual return to a life without tobacco might then begin.
Such studies are critical because many people are afraid to stop smoking on account of the potential weight they might gain. Statistics show that the average weight associated with not smoking is less than 10 pounds, or about 5 kilograms.
In lab experiments conducted on unsuspecting rats, researchers at the Yale University found that the nicotine-like substance cytisine activated a nicotine receptor located in the hypothalamus. This area of the brain has been associated with controlling food intake in humans.
When cytisine was not bound to these receptors, the reduction of food intake generally associated with smoking was no longer visible. “These mouse models allow us to explore the mechanisms through which nicotine acts in the brain to reduce food intake,” Marina Picciotto explains.
“We found that nicotine reduced eating and body fat through receptors implicated in nicotine aversion and withdrawal rather than reward and reinforcement,” adds the expert, who is based at the Yale University. She is also the senior author of a new study detailing the findings.
Details of the research appear in the June 10 issue of the top journal Science. The study was funded by the National Institute on Drug Abuse (NIDA), a part of the US National Institutes of Health (NIH).
“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,” explains NIDA director Dr. Nora D. Volkow.
“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,” adds the official, quoted by PsychCentral.