A recent study revealed that the liver hormone, fibroblast growth factor 21 (FGF21), signals the brain to suppress the preference for sweets and alcohol in mammals. The study was led by UT Southwestern Medical Center researchers, and has been published in the journal Cell Metabolism.

The hormone FGF21 is produced by the liver, in response to the increase in carbohydrate levels, suppressing the consumption of simple sugars. When the hormone enters the bloodstream, it signals the brain to determine preference for sweets. During the study, researchers found that mice with increased levels of the liver hormone, showed a lesser preference for sweetened water and alcohol-laced water.

“We have known for a while that FGF21 can enhance insulin sensitivity,” said Lucas Bondurant, a doctoral student in Molecular and Cellular Biology and co-author in the study. His co-senior author Matthew Gillum of the University of Copenhagen, said:

“We never imagined that a circulating, liver-derived factor would exist whose function is to control sweet appetite. We are very excited about investigating this hormonal pathway further.”
Co-senior author of the study, Dr. Steven Kliewer stated that FGF21 administration could possibly affect nutrient preference and other reward preference behaviors in humans, and the liver hormone could potentially be used to treat alcoholism. Though studies have been carried out to find the effect of hormones on appetite, they did not regulate any specific macronutrients like carbohydrate, fat or protein. However, the latest study could help in treating obese or diabetic patients.

The study is based on earlier genome-based studies, where scientists found associations between some DNA mutations and people’s intake of certain macronutrients. Two mutations were located near the FGF21 gene, prompting the researchers to further examine the role of the hormone in macronutrient preference.

Kliewer stated that the finding that FGF21 acts via the brain was completely unexpected when we started down this path of investigation a dozen years ago. The findings suggest that additional studies are required to determine the effects of FGF21 on sweet and alcohol preference and other reward behavior in humans.