Does Smoking Weed Cause Lung Cancer? A Lung Cancer Doctor Shares “the Short Answer”
Research suggests marijuana use has increased 20% with wider legalization. Here, a leading pulmonary oncologist helps clarify whether weed leads to lung cancer, as cigarette smoking can.
If you’ve ever taken a puff of marijuana, chances are good you’re familiar with the sensation it can create in the airway. It’s irritating…but can it cause serious health issues? By now, nearly a century’s worth of research has left little doubt that cigarettes increase the risk of developing lung cancer. With more U.S. states legalizing marijuana, can smoking weed cause lung cancer too?
As of 2019, marijuana was reported to be the most commonly used federally illegal drug in America, with 48.2 million Americans using it. However, after approximately half of US states made moves to legalize or decriminalize cannabis starting around 2020, peer-reviewed research in 2022 suggested the frequency of recreational marijuana use had increased by about 20%. Despite the wider use of marijuana, the research surrounding cannabis and lung cancer is nascent.
According to Mayo Clinic pulmonologist Aryan Shiari, MD, “Additional research is needed to fully understand the long-term health effects of marijuana smoking and how it affects a person’s risk for lung cancer.” Keep reading—a New York City lung cancer doctor speaks to what the current science is saying.
Does smoking weed cause lung cancer?
So, does smoking weed increase your risk of developing lung cancer? “The short answer is likely yes,” Daniel H. Sterman, MD, director of the lung cancer program at NYU Langone Health, tells The Healthy @Reader’s Digest. “But there is a lot to be learned about the biological effects of marijuana upon the lungs,” Dr. Sterman says, “and this depends on a number of variables.”
According to Dr. Sterman, the main variables include:
- how much and how often cannabis is smoked
- the mechanism through which it is smoked (i.e. joint, water pipe, electronic cigarette, etc.).
“There are an increasing number of individuals—especially young adults—who are vaping tetrahydrocannabinol (THC),” Dr. Sterman says. “[This] poses other risks of metal fumes, THC chemical excipients, etc., which can contribute to lung cancer development.” All of which need further study, he adds.
On the flip side, there’s research, including one 2017 study, noting possible benefits of cannabis and cannabinoids for patients who have lung cancer. For those folks, cutting it out entirely might not be an option.
How might cannabis benefit people with lung cancer?
“There are several perceived benefits of cannabis in patients with several chronic illnesses, including lung cancer,” Dr. Sterman explains. “The most well studied beneficial effects of medical marijuana are likely in attenuating side effects from cancer chemotherapy,” he says.
These side effects include pain, nausea, and vomiting. It’s also been beneficial in “enhancing appetite in patients with cancer cachexia,” which is described as the chronic weight and muscle loss in patients with advanced cancer. According to the National Cancer Institute, “cachexia is most common in people with advanced pancreatic and lung cancer.”
These studies, however, have a “relative lack of high-grade clinical evidence such as in large, randomized controlled clinical trials,” Dr. Sterman notes. And with already-weakened lungs, it’s critical that lung cancer patients practice caution when using marijuana to treat their symptoms.
Dr. Sterman offers his own lung cancer patients a couple suggestions. “I have several patients with advanced lung cancer who are using medical marijuana to control their cancer or cancer treatment related symptoms,” he tells us, “and I have encouraged these individuals to consider non-inhaled forms of medical cannabis.” This might include edibles, THC beverages, or tinctures, to name a few.
How does smoking weed compare to tobacco’s lung cancer risk?
Inhaling smoke of any kind has the potential to irritate your lungs, but it’s unclear whether tobacco or marijuana smoke has more negative, long-term effects.
“It is challenging to make a direct head-to-head comparison,” Dr. Sterman tells us, “but smoking marijuana can result in many of the chronic lung diseases that smoking tobacco can induce.”
A 2013 review published in the Annals of the American Thoracic Society found an association between regular use of weed and airway injury. The symptoms, indicative of chronic bronchitis, are recurring cough, increased mucus production, and wheezing.
However, 2012 research in COPD: Journal of Chronic Obstructive Pulmonary Disease, had shown that when users stopped smoking marijuana, their symptoms would subside. This outcome may be attributed to the quantity of smoke inhalation. According to the Annals of the American Thoracic Society review, regular tobacco users will smoke approximately 20 cigarettes per day or more, compared to regular marijuana users, who usually smoke fewer than a few joints per day.
“The other complicating factor is that many individuals, particularly young adults, are smoking combinations of tobacco and marijuana,” Dr. Sterman adds, “and the biological effects of this combination have not yet been well studied.”
Because of the potential lung irritants associated with smoking, Dr. Sterman says, “All individuals with underlying lung disease—including asthma and chronic obstructive pulmonary disease (COPD)—should be extremely cautious about smoking cannabis or tobacco.”
There are both perceived benefits and potential risk of marijuana, and more research is needed to clearly understand the long-term effects of smoking weed.
“There is a relative dearth of large public health studies of the lung cancer risks of combustible cannabis,” Dr. Sterman concludes. “But these need to be conducted given the increasing number of states with marijuana legalization for medical and/or recreational purposes.”