Washington: A hormone released by the stomach also has the potential to stimulate alcohol craving, a new study has found.
Ghrelin is a hormone released by the stomach and it stimulates appetite and food intake.
Alcohol is commonly viewed as a psychoactive substance that primarily affects brain function, but it is also a highly caloric food.
This knowledge, combined with findings from animal studies, led researchers to the hypothesis that ghrelin has the potential to stimulate alcohol craving.
Researchers tested this in humans and found that, as they had anticipated, alcohol craving was increased in heavy drinkers following administration of ghrelin.
"This study provides a direct translation on the role of ghrelin in alcohol-seeking behaviours in humans from previous research conducted in rodents," said Dr Lorenzo Leggio, Clinical Investigator in the National Institute on Alcohol Abuse and Alcoholism (NIAAA) and the National Institute on Drug Abuse at the National Institutes of Health.
The study was conducted in the laboratory, where 45 men and women, all of whom were alcohol-dependent, heavy-drinking individuals not seeking treatment, were randomised to receive one of three different doses of ghrelin. One of those doses, at 0 microgrammes per kilogramme, served as a placebo.
Following intravenous administration of the drug, the volunteers then completed a cue-reactivity task, during which they were exposed to both neutral and alcohol cues.
Throughout the laboratory session, their craving (eg, urge to drink) for alcohol or juice was repeatedly assessed.
Compared to placebo, ghrelin significantly increased alcohol craving, but had no effect on urge to drink juice.
There were no differences in reported side effects between those who received placebo versus those who received ghrelin.
The study was published in the journal Biological Psychiatry.
