Perhaps we shouldn’t feel so guilty about eating junk food from time to time, but rather the blame may lie with our brain chemistry: the newly discovered NPGL protein involved in brain signaling has been blamed for increase body fat storage, even on a low-fat diet, as well as increase appetite in response to high calorie intake.
This is pointed out by research from the University of Hiroshima together with collaborators from Japan and UC Berkeley, which sheds more light on our understanding of how the brain regulates energy use and eating habits. The finding is relevant, because the energy control mechanisms are still not very well understood by scientists.
“For most of our evolutionary history, the brain did a seemingly good job of regulating the distribution of body fat, accumulating fat essential for survival during times of famine,” says Professor Kazuyoshi Ukena, lead author of the study. “Unfortunately, in today’s Western life, when there is an abundance of food, fat is often eaten in excess, often leading to obesity, ” he says.
The researchers conducted experiments on rats fed two different diets for six weeks. One diet was high in calories, high in fat and sugar. The other diet contained only enough calories necessary for healthy survival. A virus was then prepared that would cause NPGL-secreting cells to increase production in the hypothalamus of both sets of rats.
The observations found that NPGL was present in high concentrations in a specific part of the rat hypothalamus, the brain’s control center for appetite and metabolism , suggesting participation in the regulation of body energy.
In rats fed the high-calorie diet, body mass and the proportion of the body composed of fatty tissue both increased markedly. Interestingly, food intake largely despite animals having an overabundance of calories. In rats fed regular calories in which NPGL production was induced, the animals did not increase overall body mass and only moderately increased food consumption. However, the composition of body fat, as with the high-calorie diet, increased significantly.
In contrast, when rats on the high calorie diet were exposed to an antibody that inhibits NPGL synthesis, the proportion of fatty tissues in the body decreased , further demonstrating a critical role for NPGL in regulating the composition of the protein. body fat. In these rats, food intake and overall body mass remained unchanged.
A warehouse for times of scarcity
NPGL levels were also observed to rise and fall proportionally with insulin levels in the blood, suggesting that this energy storage hormone coordinates with the NPGL system to store fat in peak periods and thus limit production. of fat when there is a shortage of food.
Together, these findings reveal an intricate neurochemical system where signals from the brain and other tissues combine to monitor the body’s energy status and adjust eating and metabolism.
“Because dysregulated energy balance can result in obesity and lead to serious health problems such as diabetes and cardiovascular disease, it is vital that we gain an understanding of the mechanisms that regulate appetite and body fat, ” the researchers note. .
