Gut hormone may be to blame for bad financial decisions

BOSTON, Mass. — Among other functions, the stomach hormone ghrelin triggers appetite and initiates the accumulation of fat in the body. Now, research indicates the “hunger” hormone may also trigger impulsive spending, especially when it comes to items that “feed” the brain’s reward center.

According to co-author Franziska Plessow, Ph.D., assistant professor of medicine at Massachusetts General Hospital and Harvard Medical School, this study reveals unique indications that ghrelin influences financial choices in humans. Similarly, ghrelin may have a role in spontaneous activity and decisions, according to her analysis of current studies in rats.

“Our results indicate that ghrelin might play a broader role than previously acknowledged in human reward-related behavior and decision making, such as monetary choices,” Plessow says in a media release. “This will hopefully inspire future research into its role in food-independent human perception and behavior.”

Does ghrelin make people more impulsive?

Ghrelin works by activating the portion of the brain that controls food intake. The hormone can also alter circuits in the brain related to the reward center located in the frontal lobe. Researchers add that levels of this hormone vary according to consumption and a person’s distinct metabolic activity.

The research consisted of 84 females, all between the ages of 10 and 22. Among these participants, 50 suffered from anorexia nervosa, while the remaining 34 were healthy individuals which made up the control group. Each person ate the same meal during the experiment did not eat prior to the study. Plessow’s team measured total ghrelin concentrations in the blood prior to and after consumption.

Participants then took part in a test featuring a series of hypothetical financial decisions, which scientists call the delay discounting task. The survey gave them the option of choosing between a smaller financial reward they received right away or a bigger cash prize 14 days later.

The team found that healthy individuals, as well as those with increased concentrations of ghrelin, tended to prefer receiving a lesser quantity of money now (for example $20 today) over waiting for a greater sum (for example $80 two weeks later). In Plessow’s opinion, this inclination suggests a greater tendency toward impulsive behavior.

There was no link between ghrelin levels and financial decisions in those of the same age who were underweight due to anorexia nervosa, which has been reported to be resistant to ghrelin. These results, according to Plessow, could be an additional hint of a mismatch between the hormone’s activation and the habits of those with anorexia nervosa.

Researchers presented their findings at ENDO 2021, the Endocrine Society’s annual meeting.