A group of scientists at Imperial College London discovered, studying rats, a brain mechanism that senses how much glucose is reaching to the brain, and prompts animals to seek for high glucose foods if detects a shortfall.
An enzyme called glucokinase is involved in sensing glucose in the liver and pancreas. Scientist previously knew this enzyme is present in the hypothalamus, an area of the brain that regulates a variety of essential functions including food intake, but its exact role was unclear. A team at Imperial College London hypothesized that glucokinase might play a role in driving our desire for glucose.
In the study, published in the Journal of Clinical Investigation, researchers first discovered that when rats go for 24 hours without eating, the activity of glucokinase in an appetite-regulating center in the hypothalamus increases sharply.
The rats were given access to a glucose solution as well as their normal food pellets, called chow. When the researchers increased the activity of glucokinase in the hypothalamus using a virus, rats consumed more glucose in preference to chow. When glucokinase activity was decreased, they consumed less glucose.
Dr. James Gardiner, from the Department of Medicine, who led the study, said: “Our brains rely heavily on glucose for energy. It’s clearly a very important nutrient, 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.”
According with Dr. Gardiner it might be possible to reduce cravings for glucose by altering one’s diet. Furthermore, it may be possible a drug acting on this system that could potentially prevent obesity.
Source: Imperial College London, Journal of Clinical Investigation
