Though we realise that exercise is beneficial to our health, there is still much to learn about the complex and diverse ways in which physical activity promotes positive health outcomes in humans. Scientists studying the molecular specifics of this association have made a key finding, identifying a modified amino acid that increases in the blood after strenuous exercise and travels to the brain to reduce hunger and, as a result, induce weight reduction.
“We’re all aware that exercise is good,” said Jonathan Long, an assistant professor of pathology at Stanford University and the study’s lead author. “It helps with body weight and glucose regulation.” But we wanted to dig deeper into that concept, to see if we could dissect exercise in terms of molecules and pathways.”
Long and his colleagues from the University of California, Davis, and Baylor College of Medicine used a technology known as metabolomics to do this. This entailed using mass spectrometry to track the quantity of various chemicals in tissue and blood samples, as well as how exercise affected the amounts of particular compounds.
Initially, this was tested on mice who were subjected to a short treadmill exercise, with the scientists able to identify a huge rise in a specific chemical following the workout. The team then examined blood from racehorses and discovered a surge in the same unknown chemical following their exertion.
“I remember seeing that and thinking, ‘OK, now there’s something here,'” Long explained.
“Wow, all of these lines of evidence point to lac-phe travelling to the brain to inhibit feeding,” he added.
While the findings are crucial for our understanding of how exercise affects hunger levels and can have subtle and indirect weight loss advantages beyond merely burning calories, the researchers note that the research is still in its early stages. Translating this research into a “diet pill” that suppresses appetite will be a long path that will begin with better knowing how lac-phe reduces hunger signals and discovering the brain receptors that assist this effect.
“Regular exercise has been shown to enhance weight loss, manage appetite, and improve the metabolic profile, especially in patients who are overweight or obese,” stated Baylor College of Medicine co-corresponding author Dr. Yong Xu. “If we can understand the process by which exercise produces these benefits, we will be one step closer to assisting many people in improving their health.”