The holidays are over and so are the binge eating over Christmas. Many a person has now made a resolution to keep their hands off sugar and sweets. In the Arctic, too, there have been warnings about the effects of excessive sugar consumption. But some Greenlanders can responsibly ignore this advice. As Danish researchers have now discovered in a study, a small percentage of the Greenlandic population has a genetic variation that confers health benefits from sugar consumption.
Who wouldn’t love to actively do something for their health by indulging in sweets? Cake in the morning, chocolate and biscuits at lunchtime and ice cream in the evening, accompanied by sweet lemonade: a little exaggerated, but such a menu would certainly please many instead of broccoli, spinach, potatoes and carrots. And if the body thanks you with a lower body mass index, lower body weight, lower cholesterol levels and less body fat, all the better. Indeed, all these are the effects that the scientists from the University of Copenhagen, the University of Southern Denmark and other institutions have observed in a proportion of the Greenlandic population after sugar consumption. In western societies, on the other hand, where a carbohydrate-rich diet dominates, too much sugar consumption has the opposite effects, with sometimes serious consequences for the cardiovascular system.
“Adult Greenlanders with the genetic variation have lower BMI, weight, fat percentage, cholesterol levels and are generally significantly healthier. They have less belly fat and might find it easier to get a six pack. It is amazing and surprising that a genetic variation has such a profoundly beneficial effect”, says Anders Albrechtsen, biology professor at the University of Copenhagen.
The researchers studied 6,551 adult Greenlanders and also conducted experiments on mice. They found that carriers of the variation, about 14 percent of those studied, were deficient in the enzyme sucrase-isomaltase, which is responsible for breaking down polysaccharides in the gut. This means that sugar is not absorbed normally in the bloodstream as it is in people without this genetic variation. Instead, the sugar goes directly into the intestines.
“Here, gut bacteria convert the sugar into a short-chain fatty acid called acetate, which in previous studies has been shown to reduce appetite, increase metabolism and boost the immune system. That is most likely the mechanism happening here”, explains Mette K. Andersen, assistant professor at the Center for Metabolic Research at the University of Copenhagen and lead author of the study.
The authors attribute this peculiarity to the special diet of the Greenlanders, which has differed from the rest of the world for thousands of years. “It is probably due to Greenlanders not having had very much sugar in their diet. For the most part, they have eaten meat and fat from fish, whales, seals and reindeer. A single crowberry may have crept in here and there, but their diet has had minimal sugar content”, says Anders Albrechtsen. Thus, the traditional diet has led to frequent genetic variation because there has never been a need to quickly absorb sugar into the bloodstream.
However, it is not good news for children if they are carriers of the variation – sucrase-isomaltase deficiency brings them unpleasant problems. “Younger carriers of the variation experience negative consequences due to their different type of sugar absorption. For them, consuming sugar causes diarrhea, abdominal pain and bloating. Our guess is that as they age, their gut bacteria gradually get used to sugar and learn how to convert it into energy”, explains Torben Hansen, a doctor and professor at the Foundation Center for Basic Metabolic Research at the University of Copenhagen.
The research team hopes that the results of the study may lay the groundwork for the development of new drugs that could one day be used to treat cardiovascular disease and obesity.
“We can see that the genetic variation provides a better balance of fat in the bloodstream, which results in lower weight and consequently, fewer cardiovascular diseases. If you can develop a drug that inhibits the sucrase-isomaltase gene, then in principle, we might all be able to have equally strong health profiles”, says Hansen.
Julia Hager, PolarJournal
Link to the study: Mette K. Andersen, Line Skotte, Emil Jørsboe, Ryan Polito, Frederik F. Stæger, Peter Aldiss, Kristian Hanghøj, Ryan K. Waples, Cindy G. Santander, Niels Grarup, Inger K. Dahl-Petersen, Lars J. Diaz, Maria Overvad, Ninna K. Senftleber, Bolette Søborg, Christina V.L. Larsen, Clara Lemoine, Oluf Pedersen, Bjarke Feenstra, Peter Bjerregaard, Mads Melbye, Marit E. Jørgensen, Nils J. Færgeman, Anders Koch, Thomas Moritz, Matthew P. Gillum, Ida Moltke, Torben Hansen, Anders Albrechtsen. Loss of sucrase-isomaltase function increases acetate levels and improves metabolic health in Greenlandic cohorts. Gastroenterology, 2021; DOI: 10.1053/j.gastro.2021.12.236