The usage of marijuana has been a heavily debated subject. Many states have looked into legalizing the controlled substance as there are many potential benefits to it, while others have understandably pointed out how it can cause harm as well as lead to addiction. Cannabis is the most commonly used substance after alcohol and tobacco, according to a 2018 Journal of Neuroimmune Pharmacology study, US also saw an increase in cannabis use disorder (CUD) as well as a decrease in the perceived risk of cannabis. However, the researchers have now found a concerning link between cannabis and oral cancer. A new study suggests that people who smoke a lot of marijuana may be over three times more likely to get oral cancer. This risk is even higher for those who also smoke cigarettes. The study's lead author explains that cannabis smoke contains many of the same cancer-causing chemicals found in tobacco smoke, which can damage the cells that line the mouth over time. Previous Speculations about Cannabis and Cancer Interestingly, previous researchers have shown that cannabis compounds could actually benefit people. According to a 2024 International Journal of Molecular Sciences study the previous studies on the same have had mixed answers. However, lab research on oral cancer cells has shown some promising anti-cancer effects. In these studies, cannabinoids have been found to kill cancer cells and stop them from multiplying. They do this by blocking certain signals within the cancer cells. Beyond fighting cancer, cannabinoids are already used in some countries to help cancer patients feel better during treatment. They can help with common side effects of chemotherapy and radiation, such as anxiety, depression, pain, and nausea, which improves a patient's overall well-being. The relationship between cannabis compounds and oral cancer is complicated. While there is promising evidence that cannabinoids could have anti-cancer properties and help manage treatment side effects, more research is needed to fully understand their potential risks and benefits. How the Study Was Done Published in the journal Preventive Medicine Reports, the research looked at the health records of over 45,000 patients. The team focused on 949 people with cannabis use disorder, which means they used marijuana almost every day. The researchers tracked these patients for five years to see who developed oral cancer. They also made sure to account for other risk factors, like a person's age or whether they smoked cigarettes, to get a clearer picture of the risk from marijuana alone. What the Study Found The results were very clear. People with cannabis use disorder were 325% more likely to get oral cancer than those who didn't have the disorder. This risk jumped to 624% for people who were heavy users of both marijuana and cigarettes. Researchers believe that the high risk of oral cancer in heavy marijuana users isn't just because of smoke. It's possible that THC, the main compound in marijuana, might weaken the immune system. A weaker immune system would make it harder for the body to fight off cancer cells, making a person more vulnerable to developing a tumor. This new evidence adds to a growing body of research that suggests long-term, heavy use of marijuana may increase cancer risk in the areas exposed to smoke.