Monday, February 01, 2016

 A research team lead by Matthew Potthoff, PhD, Assistant Professor of Pharmacology and member of the FOEDRC, at the University of Iowa recently discovered a liver hormone that appears to regulate sugar intake.

A liver hormone called hepatokine fibroblast growth factor 21 (FGF21) influences cravings for sugar, according to a mouse study published in December in Cell Metabolism. It is the first hormone found to regulate the consumption of a specific nutrient; other appetite-regulating hormones such as ghrelin and leptin—produced in the gut and in fat cells, respectively—act much more broadly, regulating overall caloric intake.

Specifically, Potthoff and his colleagues found that FGF21 suppresses a mouse’s consumption of simple sugars, but not of complex carbohydrates, proteins, or lipids. Mice lacking FGF21 drank much more sugary drink, while mice that overexpressed FGF21 or were dosed with the hormone consumed less sugar and noncaloric sweeteners. FGF21 appears to mediate such sweet-eating behavior via the appetite regulating center in the brain called the hypothalamus, and the hormone increases following sugar consumption, suggesting a negative feedback loop that regulates sugar intake.

“We conclude that the liver functions to regulate macronutrient-specific intake by producing an endocrine satiety signal that acts centrally to suppress the intake of ‘sweets,’” the authors wrote in their paper.

The identification of this key liver hormone could help you squash your sugar habit and help regulate your sugar intake by communicating with your brain when you've had enough, essentially shutting down your own desire for sweets. This is the first time a single mechanism has been found in the liver that can control cravings. 

The research could improve diets and help patients who are diabetic or obese.

“We’ve known for a while that FGF21 can enhance insulin sensitivity,” says Lucas BonDurant, a doctoral student in the Interdisciplinary Graduate Program in Molecular and Cellular Biology and co-first author in the study. “Now, there’s this dimension where FGF21 can help people who might not be able to sense when they’ve had enough sugar, which may contribute to diabetes.”

These studies have garnered widespread global attention and news coverage.