Gene mutation evolved to cope with modern high-sugar diets
A research team at University College London found that about 50% of people with a mutated gene contribute to lowering blood sugar levels. According to these researchers, humans have developed this mutation as we develop culinary and agricultural practices, so that it can protect us from the onset of diabetes.
A mutation to lower the sugar level
This research is the result of a study on a gene called CLTC1, which controls the production of a protein called CHC22. This protein regulates the mechanism by which glucose exits our blood and enters our fatty and muscular tissues. By examining ancient human DNA, different animal species and the genomes of more than 2,500 modern humans, researchers discovered that the mutation of the CLTC1 gene appeared to appear in humans at the time we began cooking our food 450,000 years ago.
The mutation of this gene produces a modified expression of the CHC22 protein, which reduces the efficiency of this glucose transport process between the blood and muscle or fat. This essentially means that this mutation allows glucose to be removed more quickly from our blood after a meal.
"The old version of this genetic variant would probably have been useful to our ancestors, because it would have maintained higher blood sugar levels during fasting periods, when we did not have such easy access to carbohydrates, which would have helped our great brains evolve," said Matteo Fumagalli, first author of this new study.
The most recent mutation of the CLTC1 gene was first discovered in older humans, but researchers noted that it was becoming more frequent as the prevalence of agriculture increased more than 10,000 years ago. As carbohydrates became more readily available in our diet, the need to more effectively remove glucose from our blood increased the spread of this highly specific gene mutation.
Prehistoric changes have shaped human evolution
"Our analyses strongly suggest that we have found another example of how prehistoric changes in our eating habits have shaped human evolution," says Mark Thomas, co-author of the study. "Understanding how we have adapted to these changes not only informs us about the reasons for people's lives or deaths in the past, but also helps us to better understand the relationship between food, health and disease in our time. »
It is interesting to note that this new genetic mutation has not totally eliminated during human evolution. The researchers reported that nearly half of the human genomes studied still contained the old version of the CLTC1 gene. The importance of the role of the new gene variant in humans is unclear and it should be noted that the oldest genetic variant does not appear to play a direct role in the development of diabetes.
A variant that could exacerbate insulin resistance
However, the researchers note that this genetic variant may exacerbate insulin resistance in some people and put them at increased risk of developing type 2 diabetes. "People with the oldest variant may need to pay more attention to their carbohydrate intake, but more research is needed to understand how this genetic variant can affect our physiology," says Frances Brodsky, lead author of this research.
