Scientists from the University of Iowa have determined that a particular liver hormone may tell our brain when it's time to put down the candy bars. It's called FGF21, and when released, it causes the body to crave less sugar.
"This is the first liver-derived hormone we know that regulates sugar intake specifically," says Matthew Potthoff, co-senior author on the paper, in a press release.
Researchers have known for some time that certain hormones can affect appetite, but this is the first study showing a specific hormone is tasked with regulating the intake of a macronutrient. One conclusion could be that people with a pronounced "sweet tooth" may have low FGF21, or fibroblast growth factor 21, production. The hormone has also been linked to insulin sensitivity.
The research involved injecting specially-engineered mice with FGF21 and observing their appetites. The mice given the hormone ate a seventh as much sugar as they did before the injection. The scientists also noted that the hormone didn't cause the animals to eat fewer complex carbs. The role of FGF21 has not yet been studied in humans.
"We've known for a while that FGF21 can enhance insulin sensitivity," says Lucas BonDurant, also a co-author of 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."
The next step will be to find out which parts of the brain respond to FGF21, so that this research might be turned into treatment. It will also give a hint as to where to look for hormones that regulate other macronutrients, like fat and protein.
The research on FGF21 was published online in the journal Cell Metabolism.