More than one-third of the US population is considered obese. A condition that is becoming more and more common among Americans, obesity has caused national concern due to its connection to serious illnesses such as diabetes, stroke, and cancer. Recently, researchers from the University of Kentucky have discovered a genetic marker that provides new insight on the disease.
This marker, named neurotensin (NT), is a 13 amino acid neuropeptide–a small protein molecule that neurons use to communicate–that is distributed all throughout the central nervous system and the enteroendocrine cells of the small intestine.
For years, scientists and researchers have studied the neuropeptide and its role in modulation of dopamine signaling in the brain. Its effects on the brain resembles those of antipsychotic drugs–leading many to believe that there is potential for it to be used as psychiatric medication. Further studies have shown that the neuropeptide also plays a key role in thermoregulation; during cerebral inchemia, it is capable of inducing hypothermia and neuroprotection to protect the body.
From these past studies, there is no doubt that neurotensin plays a key role in regulating the brain’s mental state. However, the new study, which was published in Nature, shows that the concentration of pro-NT, a neurotensin precursory hormone, can be directly correlated to obesity. In this study, a population-based group of 28,449 men and women were followed for around 16.5 years. Data showed that obese and insulin-resistant participants had, on average, a significantly higher concentration of fasting pro-NT than those who were non-obese. In addition, non-obese participants with higher levels of fasting pro-NT had double the risk of becoming obese. In fact, NT-deficiency actually protected against obesity. Thus, a link has been found between NT and fat absorption.
It is imperative to understand that this new discovery does not discredit traditional biological markers for obesity such as the hormone leptin, which is associated with “turning off” the feeling of hunger. In the study, NT-deficient mice were slightly thinner than normal; however, without NT-receptors, the mice should have been immune to the effects of leptin and therefore unable to control their hunger. This indicates that the relationship between NT and leptin is more complicated than we thought and may need further studying.
Obesity is a complex condition that has a variety of causes ranging from carbohydrate consumption to lack of exercise. Neurotensin, however, has only been linked to fat absorption and therefore high-fat diets. Therefore, while it is an important cause of obesity, it is only one of many. Even so, with this knowledge and further research, neurotensin has the potential to play a huge role in our fight against obesity.
Feature Image Source: Measuring Tape by Jamie