With the end of the year approaching, keeping an eye on the diet becomes a difficult task. Just see or smell the Christmas dinner to make your mouth water.
According to a study published in the scientific journal Cell Reports , one of the reasons that this desire to eat appears so strongly may be a hormone found in the stomach.
According to the researchers, ghrelin leaves people more vulnerable to the smell of tasty food, which can stimulate overeating and obesity .
Jointly done by the Montreal Neurological Institute and McGill University Hospital, this new research used functional magnetic resonance imaging to record the brain activity of 38 patients who received doses of ghrelin.
After receiving a dose of the hormone, patients were exposed to a variety of odors, both food and non-food.
All of this while observing neutral images of random objects, causing patients, in time, to associate the images with odors.
The smell and the reward responses
Through this method, the researchers were able to perceive activities in regions of the brain known to be involved in the dopamine reward response, (the pleasure neurotransmitter).
They found that activity in these regions was higher in patients who took doses of ghrelin, but only when they responded to images associated with food smells.
For researchers, this means that ghrelin has a direct effect on the way the brain associates food with the feeling of well-being.
In other words, we can say that the action of ghrelin in the human body is responsible for gluttony, one of the seven deadly sins.
The pleasantness of the images associated with food odors was also evaluated, that is, the patient saw the images he related to the food odor and should answer how much the image pleased him.
The results showed that patients who took ghrelin had a shorter response time and a greater sense of pleasure when they saw the images they associated with food odors compared to images associated with non-food odors.
Thus, it was possible to reach the conclusion that the action of ghrelin in the body has an impact on the way we perceive and react to smells.
That is, keeping your mouth water is not only the fault of the lasagna baking in the oven, but also the action of this hormone in the brain.
The “hunger hormone”
Ghrelin is already a hormone known to scientists, as is its relationship with obesity.
The doctor responsible for this research had already coordinated other studies that demonstrated the relationship between ghrelin and the desire to eat and the production of dopamine.
This hormone (ghrelin) was first identified in the stomach of rats, in 1999. In addition to stimulating hunger, it is also a potent stimulator of the release of GH, the growth hormone.
The relationship between ghrelin and obesity, however, occurs in conjunction with another hormone, leptin.
Leptin can be described as the satiety hormone. It reduces appetite, playing an important role in metabolism.
It works like this: the body has a high production of ghrelin, which increases the desire to eat. The person eats and, when the food goes to the intestine, there is an increase in the production of leptin, which causes the feeling of satiety to set in.
One of the hypotheses raised by researchers and experts in the field to explain obesity is that obese people would have a dysregulation in these hormones, with high amounts of ghrelin and leptin in the body.
That way, the person would always be hungry, since ghrelin is at higher levels, and would not feel satiated, because, in time, the body would be resistant to the action of leptin.
Why is discovery important?
Although the real origin of obesity is not yet known, these hypotheses may allow the emergence of new treatments and a greater understanding of the disease.
It is already known that people with obesity have an abnormal reactivity to food stimuli, which are abundant in our environment, such as fast food advertising .
The study shows that ghrelin can be an important factor in this increased response to food suggestion. The brain regions identified and studied in this research have been associated with greater vulnerability to obesity.
In the words of Dr. Alain Dagher, the person responsible for the study, the research made it possible to understand a little more about the mechanism by which ghrelin makes people more vulnerable to hunger, “(…) and the more we know about it, the easier it will be to develop therapies that neutralize this effect ”.
Understanding more about how hormones influence our behavior is very important so that we are not enslaved by them.
In the case of people with hormonal disruptions, this understanding is even more necessary for effective therapies to be developed.
More texts on hormones, the human body and news from the world of health can be found in the Healthy Minute!