Doctors have long warned that breathing smoke into the lungs is harmful. Tobacco smoking has been strongly linked to lung cancer for decades. New research now suggests that smoking marijuana may also carry serious risks.
A 2021 study examined young men with lung cancer who required surgery. Researchers found that those who smoked cannabis, especially together with tobacco, developed larger tumors and faced more complications after surgery. Their cancers also showed changes that suggested more aggressive disease.
Scientists also found that marijuana smoke contains many of the same cancer-causing chemicals found in tobacco smoke. In some cases, cannabis smoke may contain even higher levels of harmful substances. According to Brooks Udelsman, people who smoke large amounts of marijuana appear to have a higher risk of developing cancer.
Experts say one major unknown is how much marijuana use becomes dangerous. Occasional use may carry less risk, but heavy or frequent smoking can cause long-term lung inflammation, which increases cancer risk.
The message from health professionals is clear: marijuana smoke is not harmless. Regular use can damage the lungs and may also affect the heart and brain over time.