Do you have a sweet tooth? Blame it on your liver
New research shows that a certain hormone produced in the liver could explain your sweet tooth and help produce new treatments to reduce people’s cravings for sugar.
Do you crave dessert after every meal or finish a bag of candy in one sitting? Then you may have a sweet tooth.
New research shows that one of the reasons for a sweet tooth could be found in the liver.
The liver produces a certain hormone that regulates sugar cravings and if you have a specific variant of the gene that makes this hormone, then there is a strong chance that you have a sweet tooth, say the scientists behind the new research.
The discovery of the gene could lead to new medicines to combat obesity by reducing our desire for sugar, says author Niels Grarup from the Novo Nordisk Foundation Center for Basic Metabolic Research at the University of Copenhagen, Denmark.
“We live in a world where the population eats far too much sugar. It’s partly due to the availability of sugar in sweets and candy, but for some people it’s because of this biological mechanism that makes it harder for them to control their sugar cravings. Potentially, we can use this knowledge to develop new medicines that can regulate the craving for sweet things and thereby treat obesity,” says Grarup.
The new study is published in the scientific journal Cell Metabolism.
Hormone could lead to new treatments for obesity
The study offers an interesting angle to explain today’s obesity epidemic, says Niels Jessen, a professor at the Department of Biomedicine at Aarhus University, Denmark, who studies the body’s metabolism.
“All of our efforts to reduce the obesity epidemic revolve around getting people to exercise more, but that doesn’t help some people if we don’t also do something about their appetite. This study gives an interesting insight into some of the mechanisms involved in appetite and sweet cravings,” says Jessen, who was not involved in the new study.
The hormone now needs to be tested to see if it can reduce people’s sugar cravings and combat obesity, says Jessen.
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Variant of hormone leads to sugar cravings
The hormone is called FGF21. It is released in the liver and has many different functions in the body. It is involved in fetal development, cell growth, tissue repair, tumor growth, and appetite regulation.
The new study shows that the hormone also plays a role in regulating sugar cravings and that people with a certain variant of the gene that makes FGF21 have a 20 per cent higher chance of having a sweet tooth.
“Previous studies have shown that the genetic variant changes the relationship between the amount of protein and carbohydrate that people eat. We’ve gone a step further to see precisely which food stuff it effects, and that’s sweets and other types of candy,” says Grarup.
Hormone regulates sugar cravings
FGF21 probably regulates sugar cravings by telling the brain when the body needs more sugar.
The hormone is released in the liver as it is one of the first organs in the body to come into contact with nutrients from food--in this case, sugar.
After the FGF21 is released, it reaches the brain via the bloodstream where the brain regulates our cravings.
The more sweet food we eat, the more FGF21 is produced in the liver and the more the brain is bombarded with FGF21. In the end the level of FGF21 is probably so high that the desire to eat sugar subsides.
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Difference lies outside the gene
People with one of the two specific variations of the FGF21 gene have a generally higher intake of sugar, shows the new study.
Grarup speculates that the gene does not produce as much FGF21 as the sugar intake rises.
“We can see that the genetic changes occur outside the gene, so it’s not a change in the hormone itself that causes the sugar cravings to increase, but it’s probably the amount of FGF21 that is produced. People with these two genetic variants perhaps produce more FGF21,” he says.
Read More: When science promoted sugar as healthy
New obesity treatments
FGF21 could lead to new obesity treatments. For example, it could help to produce more FGF21 so that people can quickly get control of the sugar cravings.
Other researchers are already starting to conduct similar trials on people, where they are studying whether we can use FGF21 to regulate appetite and thereby reduce the risk of obesity and diabetes.
“It’s logical that we can take FGF21 or medicine to increase the level of FGF21 and thereby regulate appetite and cravings for sugar. But we need to remember that FGF21 is also involved in many other processes in the body, which would also be affected by treatment with FGF21, just as many other processes play a role in both appetite regulation and sugar cravings,” says Grarup.
Read more in the Danish version of this article on Videnskab.dk
Translated by: Catherine Jex
- 'FGF21 is a sugar-induced hormone associated with sweet intake and preference in humans', Cell Metabolism (2017), doi: 10.1016/j.cmet.2017.04.009