Heavy Pot Smoking Not Linked to Cancer

Good news for Cheech and Chong! Hardcore potheads may be at no greater risk for lung cancer than those who only toke up occasionally, according to new research. The link between marijuana and lung cancer has been long disputed, but a new study from the International Lung Cancer Consortium (ILCCO) found that habitual pot smokers were not more likely to develop lung disease than non-habitual pot smokers, no matter how long they had used the drug. Researchers looked at data from six case-control studies of 2,159 lung cancer cases and 2,985 controls, in the U.S., Canada, New Zealand, and the United Kingdom, from 1999 to 2012. While examining the marijuana smokers—and excluding tobacco smokers—they found frequency of pot use did not affect lung cancer risk. However, researchers allowed for the possibility that an "extremely high dosage [of pot] over long periods of continued exposure,” could still be dangerous. Though other studies have claimed marijuana's cancer risks are underestimated, many believe cigarettes are far more toxic due to chemical additives in the smoke. "The conventional wisdom is that cannabis smoking is not as dangerous as cigarette smoking," says pulmonologist Michael Alberts, although he does caution that smoking anything can harm the respiratory system. But for medical marijuana patients, he says the drug may be worth the respiratory risk, depending on condition. Says Alberts: "If cannabis is indicated, and if it’s legal, and if there’s literature backing up the indication for use, then you weigh the risk of smoking and the benefit it could bring, and make the decision."