A study from the University of California, Irvine found that adolescent exposure to low-dose THC, a primary component of cannabis, disrupts energy balance and fat storage processes in adulthood, leading to a leaner body and reduced risk of obesity and diabetes. However, the altered processes also impair the ability to mobilize stored nutrients, crucial for brain and muscle activity, with the fat cells producing muscle proteins in abnormal amounts, potentially affecting physical activity and cognitive functions like attention.
Individuals who regularly consume cannabis, despite experiencing increased appetite (“the munchies”), tend to have lower body weight and a reduced risk of diabetes compared to non-users. However, researchers from the University of California, Irvine have recently discovered a potential explanation for this seemingly contradictory phenomenon, and unfortunately, it is not good news.
The researchers’ findings were recently published in the journal Cell Metabolism.
Many adults who consume cannabis daily or almost daily begin using the drug when they are teenagers. During this time of rapid physical development, the new study shows, cannabis can wreak havoc in the fine-tuned processes that govern energy storage, making the body leaner and less susceptible to obesity but also less capable of mobilizing stored nutrients needed for brain and muscle activity.
These alterations are rooted in striking molecular changes that occur within the body’s fat depots – also known as the adipose organ – which after exposure to cannabis start making proteins that are normally found only in muscle and the heart.
Researchers gave low daily doses of THC or its vehicle to adolescent mice. They then stopped the treatment and, after the animals had reached adulthood, carried out a thorough assessment of the animals’ metabolism. The results were surprising.
Mice that had been treated as adolescents with THC, but were now drug-free, had reduced fat mass and increased lean mass, were partially resistant to obesity and hyperglycemia, had higher-than-normal body temperature, and were unable to mobilize fuel from fat stores. Several of these features are also seen in people who frequently use cannabis.
To make sense of these data, the researchers dove into the molecular changes caused by THC. What they uncovered was even more surprising: fat cells of mice treated with THC looked normal at the microscope but produced large amounts of muscle proteins, which are normally not found in fat.
Muscles, on the other hand, made fewer of those same proteins. The researchers concluded that the effort required to make these ‘alien’ proteins interferes with the healthy functioning of fat cells and thus with their ability to store and release stored nutrients. This may in turn affect not only physical activity but also mental processes, such as attention, which depend on a steady influx of fuel to the brain.
“All too often we think of cannabis only as a psychoactive drug,” said Daniele Piomelli, PhD, director for the UCI Center for the Study of Cannabis, the Louise Turner Arnold Chair in the Neurosciences, and professor in the UCI School of Medicine Department of Anatomy & Neurobiology, “But, its effects extend well beyond the brain. Its main constituent, THC, mimics a group of chemical messengers called endocannabinoids, which regulate important functions throughout the body. Our results show that interfering with endocannabinoid signaling during adolescence disrupts adipose organ function in a permanent way, with potentially far-reaching consequences on physical and mental health.”
Reference: “Adolescent exposure to low-dose THC disrupts energy balance and adipose organ homeostasis in adulthood” by Lin Lin, Kwang-Mook Jung, Hye-Lim Lee, Johnny Le, Georgia Colleluori, Courtney Wood, Francesca Palese, Erica Squire, Jade Ramirez, Shiqi Su, Alexa Torrens, Yannick Fotio, Lingyi Tang, Clinton Yu, Qin Yang, Lan Huang, Nicholas DiPatrizio, Cholsoon Jang, Saverio Cinti and Daniele Piomelli, 1 June 2023, Cell Metabolism.
DOI: 10.1016/j.cmet.2023.05.002
The study was primarily funded by the National Institute on Drug Abuse.
