The liver might be responsible for our sugar cravings. Scientists find hormone associated with higher sweets intake in humans

The popular idiom of having a sweet tooth could be replace by the more medically accurate, sweet liver. Researchers form the Novo Nordisk Foundation Center found a sugar-induced hormone, associated with higher sweets intake and preference in humans, and it’s secreted by the liver.

The liver could be responsible for why some people prefer sweets more than others. Scientists working at the Novo Nordisk Foundation Center for Basic Metabolic Research identified a hormone, produced by the liver, called FGF21, and linked to a higher intake of sweets.

The team of researchers, led by Assistant Professor Matthew Gillum, found that people with particular variants of the FGF21 gene were about 20% more likely to be top-ranking consumers of sweets and candy, such as ice cream, chocolate, and gumdrops than their counterparts in the study.

“The data, mined from a study of the lifestyles and metabolic health of 6,500 Danish individuals, is a really surprising insight into the potential hormonal basis of the sweet tooth,” said Gillum in an article published by the Novo Nordisk Foundation.

Professor Gillum found the FGF21 link to sweets back in 2015 when lab tests showed that the liver-secreted hormone played a role in regulating sweet intake in rodents. Subsequent studies have shown that it also plays a role in suppressing sugar intake in primates. The scientists’ next step was to find what the role the FGF21 played when it comes to human metabolism.

Gillum and Associate Professor Niels Grarup, working together, used a study called Inter99 as a data source to figure out if the FGF21 gene associated with the hormone, can actually impact the food choice we make. By looking at the information form the Inter99 study that collected self-reported dietary intake as well as measures of bloodstream cholesterol and glucose from participants, Grarup and Gillum sequenced the FGF21 gene in the study’s participants.

They zoomed in on two variants of the gene that in earlier research had been associated with increased intake of carbohydrates. They found that individuals with either of these two variants were much more likely to consume larger amounts of sweets and candies. The article relating the findings was published in Cell Metabolism.

They also found a link between the two genes and alcohol and smoking but further research is needed in these particular cases.

Gillum and Grarup wanted to know what changes intervened in the FGF21 levels and after looking at participants that rated themselves as having an extreme like of dislike of sweets, and making them drink sugary water, the researchers found that those who disliked sweets had fasting FGF21 blood levels 50% higher than their sweet-toothed counterparts. However, after the sweet drink, FGF21 blood levels followed the same trajectories and rose to about the same levels in both groups.

What was surprising on the other hand was that scientists found no link between FGF21 and diabetes or obesity.

Now the researchers are aiming to conduct even larger studies in order to better understand how much influence does our liver have on our dietary choices.