When we look at how our habits affect our health, it can be hard to tell if a behavior directly causes a disease or if other factors are involved. To get a clearer picture, researchers used a method called Mendelian Randomization. This approach uses a person's genetic makeup as a proxy for their behavior to see if there is a direct causal link.
The study looked at people of European ancestry and found specific links between the genetic tendency to use cannabis and three types of cancer. The results showed that this genetic liability was associated with an increased risk of both esophageal cancer and lung cancer, even when accounting for cigarette smoking.
Interestingly, the data also showed a protective effect regarding pancreatic cancer. While the study provides important clues about how genetics and substance use interact with cancer risks, it is still early research based on genetic markers rather than direct clinical trials.
