Washington, DC: A questionable report released this week by the British Lung Foundation (BLF) alleging that marijuana smoke is potentially more hazardous than tobacco smoke must not overshadow years of clinical data indicating that marijuana smokers have no higher rates of lung cancer than non-users, according to NORML Executive Director Keith Stroup.
“The bottom line is that there exists no epidemiological or aggregate clinical data showing higher rates of lung cancer in people who smoke marijuana,” Stroup said. He cited conclusions from a May 2000 John Hopkins University (Baltimore, MD) study that found no association between marijuana use and head, neck, or lung cancer in young adults. That study, which featured 164 participants, is the largest case-controlled study addressing marijuana use and cancer to date.
Stroup noted that the BLF literature review did not cite the John Hopkins study, nor did it cite a 1997 study by Kaiser Permanente that observed no increase in deaths over a ten-year period among 14,000+ marijuana smokers when compared to non-smokers.
Stroup did agree that marijuana smoke arguably carries some health risks. “Like tobacco smoke, marijuana smoke contains a number of irritants and carcinogens. However, most marijuana-only smokers likely do not inhale enough smoke to cause serious lung damage. In addition, many of these carcinogens may be reduced or eliminated by the use of marijuana vaporizers and other alternative smoking devices currently banned by the U.S. government.”
Stroup also noted that the chief psychoactive ingredient in marijuana, THC, is not carcinogenic and may actually offer protection against the development of some malignancies. A 1996 U.S. toxicology study found that rats administered THC over long periods of time failed to develop cancer and had fewer tumors than rats not given the agent. A follow up study by a Spanish research team in 2000 found that injections of synthetic THC eradicated malignant brain tumors – so-called gliomas – in one-third of treated rats, and prolonged life in another third by as much as six weeks.
Lastly, Stroup argued that nothing in the BLF report justifies arresting and jailing responsible adult marijuana smokers. “Any risk presented by marijuana smoking falls within the ambit of choice we permit the individual in a free society,” he said. “We do not suggest that marijuana is totally harmless or that it cannot be abused. That is true for all drugs, including those that are legal. Clearly, however, marijuana’s relative risk to the user and society in no way justifies criminal prohibition or the continued arrest of more than 700,000 Americans on marijuana charges every year.”
For more information, please contact Keith Stroup of NORML at (202) 483-5500.