Ever wonder why your hand stretches out toward that last piece of cake or you crave for a brownie during the most inconvenient times? A group of British scientists have come up with an explanation for why glucose-rich food induces so much desire.
Researchers at Imperial College London say that it is because of a lack of glucose-rich food, which provides the main energy source for brain cells, in our evolutionary past that we crave them now.
"Our brains rely heavily on glucose for energy, but in our evolutionary past it would have been hard to come by. So we have a deep-rooted preference for glucose-rich foods and seek them out," said James Gardiner, who led the study, to Reuters.
The study "Glucokinase Activity in the Arcuate Nucleus Regulates Glucose Intake", published by the British Scientists in the Journal of Clinical Investigation on Monday, claims to have found a mechanism that can sense how much glucose is reaching the brain. The mechanism, which they discovered by experimenting on lab rats, also prompts animals to seek more glucose if it detects a shortfall.
The researchers, who began the study with the hypothesis that an enzyme called glucokinase might play a role in driving glucose desire, discovered that when rats go 24 hours without eating, the activity of glucokinase in an appetite-regulating centre of the brain increases sharply. Glucokinase is found in hypothalamus, the part of the brain that regulates various bodily functions, including food intake.
The starved rats were given a glucose solution as well as their normal food pellets, called chow. When the activity of glucokinase in the hypothalamus was raised, the rats consumed more of glucose, whereas, on decreasing the level of glucokinase activity, they consumed less glucose.
This team of British scientists believes that this study could pave the way for discovering better treatments for obesity. According to Gardiner, it might be possible to reduce glucose cravings in humans by changing the diet, and a drug that could act on this system may potentially prevent obesity.
"People are likely to have different levels of this enzyme, so different things will work for different people," Gardiner explained.