With more and more states choosing to legalize medical marijuana, there has been increased interest in using cannabis to treat certain medical conditions, such as different types of cancer. And, although cannabis has shown promise in helping patients with cancer, claims that cannabis can actually cure cancer may leave patients feeling unsure of what to believe. Sometimes it’s hard to separate fact from fiction when it comes to the role that cannabis plays in treating certain medical conditions.
A recently updated publication from the National Cancer Institute (NCI) offers an overview of evidence-based information about the effects of cannabis on different types of cancer and outlines the discoveries that science has made, as well as what remains unknown.
Administration of tetrahydrocannabinol (THC) has been shown to reduce the incidence of liver and colon cancer in animal models. Researchers have also found that cannabis may protect normal cells from death and may even kill cancer cells. So, yes, it is possible that cannabis aids in the fight against the cellular processes that promote cancer growth. But these data have not been replicated in humans, meaning that it is largely speculative for now.
The NCI review also addresses potential downsides of cannabis use: some studies have shown that cannabis might actually cause cancer.
But how could cannabis both help fight cancer and cause cancer? The answer is a little complicated. First, it is possible that cannabis works differently in a person with cancer than in a healthy person who consumes cannabis. Second, it might depend on the route of administration (smoking versus oil consumption). Third, we don’t have enough evidence to determine the link between cannabis and cancer because most studies have been performed in animal models (not humans); therefore, the link between cannabis use and cancer remains inconclusive.
So, what do we really know about cannabis and cancer?
Extensive evidence has shown that cannabis can help alleviate some symptoms associated with cancer and some side effects from cancer treatment:
Addressing nausea and vomiting:
- Dronabinol and nabilone are treatments that can be used to reduce chemotherapy-induced nausea and vomiting.
- Several studies have verified their effects on these chemotherapy side effects.
Easing pain:
- Sativex is a cannabis extract that is approved in other countries to treat pain in cancer patients.
- Both studies in animal models and humans have demonstrated its analgesic effects.
Stimulating appetite:
- Cannabis consumption has been shown to increase weight gain in cancer patients.
- Clinical studies and experiments in animal models have demonstrated the effect of cannabis on increasing appetite.
Note that, while commercially available cannabis agents, such as dronabinol and nabilone, are approved for the treatment of cancer-related side effects, the FDA has not approved cannabis as a treatment for cancer or any other medical condition. But with more controlled clinical trials underway, that could change in the next coming years.
Visit The National Institute of Health’s clinical trial database to learn more about different studies on cannabis and cancer that are currently recruiting participants.