United States—The scent of food is mouth-watering when you are hungry. On the other hand, overeating can be a turn-off, especially if you have already eaten abundantly.
The explanation of this is rooted in the interaction between the two parts of the brain that have to do with the sense of smell and behavioral motivation, as a recent study found.
Also, it is the reason that some people may not be easily able to stop eating even when they are full, which in turn facilitates obesity, according to researchers’ explanation, as reported by HealthDay.
Recent studies suggest that the strength of the communication between those two brain regions is weaker in people who have gained excessive weight.
The Role of Smell in Appetite Regulation
“The desire to eat is related to how appealing the smell of food is — food smells better when you are hungry than when you are full,” said study co-author Guangyu Zhou, a research assistant professor of neurology at Northwestern University Feinberg School of Medicine in Chicago. “But if the brain circuits that help guide this behavior are disrupted, these signals may get confused, leading to food being rewarding even when you are full.”
“If this happens, a person’s BMI could increase. And that is what we found,” Zhou added in a Northwestern news release. “When the structural connection between these two brain regions is weaker, a person’s BMI is higher, on average.”
Smells can help to guide motivation for behaviors such as eating, and the researcher confirmed this at the end. Besides, one’s perception of odorants is dependent on one’s level of hunger.
However, beforehand researchers didn’t realize the complex way that the brain responds to the sensation when eating and the sense of smell is one of the influences.
The Study Unveiled
For the study, published on May 16th in the Journal of Neuroscience, scientists analyzed MRI brain data collected by an intricate project to create a human brain map.
Key Findings: A Link to BMI
A study showed a correlation between BMI and the connection of two brain parts as, the olfactory tubercule and gray matter around the aqueduct of Sylvius.
Researchers have found a connection between the olfactory tubercule, which is vital for the sense of smell, and the reward system in the brain.
The gray matter next to the midbrain, therefore, stimulates incentive behavior in reaction to unpleasant emotions such as pain and danger. The area may also inhibit eating.
The investigators were able to generate the first human map of the circuit connecting the two areas for the first time.
The presence of healthy connections of this kind could help the person manage food intake by transmitting messages stating that eating does not feel pleasant when full, as reported by HealthDay.
On the other hand, people having the low connection or the disruption between these areas might never get these signals, and they will keep eating when they aren’t hungry according to what researchers said.