Marijuana use may increase lung cancer risk, researchers warn

While tobacco smoke’s link to lung cancer is well established, scientists are now paying closer attention to the effects of marijuana smoke on lung health. 

Marijuana smoke contains many of the same harmful chemicals as tobacco, including carcinogens and compounds that irritate lung tissue. These substances may contribute to inflammation, DNA damage, and, over time, the development of cancerous cells.

Researchers at the Keck School of Medicine of USC and other institutions have examined data suggesting that heavy, long-term marijuana use could increase the likelihood of developing both small cell lung cancer and non-small cell lung cancer.

One of the main questions remains: how much marijuana use poses a risk? According to Dr. Brooks Udelsman, a thoracic surgeon involved in the study, occasional or moderate use is unlikely to carry significant risk for most individuals. 

However, daily or heavy users may accumulate lung damage over time, increasing the risk of chronic inflammation and malignant growths. This distinction is critical as the popularity of marijuana grows among both young adults and older populations.

Different methods of consumption also play a role. While vaping avoids combustion, it is not risk-free. Preliminary studies suggest that vaping can cause inflammatory lung conditions, which may indirectly contribute to cancer risk.

Similarly, edibles bypass the lungs entirely, but they do not mitigate other potential health risks associated with cannabis, such as cardiovascular effects or cognitive impact.

Researchers are also exploring whether secondhand marijuana smoke could affect nonusers. Early evidence indicates that inhaling smoke from any source exposes the lungs to fine particles and carcinogens, though more research is needed to determine its true impact on lung cancer risk.

While these findings are significant, experts emphasize that current data are still limited. Long-term, large-scale studies are required to clarify the relationship between marijuana use and lung cancer risk.

Meanwhile, healthcare professionals advise moderation, awareness, and open discussion about potential risks with patients who use cannabis regularly.