Increasing Evidence of Marijuana's Harmful Effects
A new finding challenges the popular belief that smoking marijuana is less harmful than smoking cigarettes. Canadian researchers are reporting that smoking marijuana, like smoking tobacco, has toxic effects on cells.
Rebecca Maertens and colleagues note that people often view marijuana as a “natural” product and as being less harmful than tobacco. As attitudes toward the drug change and legal restrictions ease in some countries, marijuana use is increasing.
Scientists already know that marijuana smoke has adverse effects on the lungs. However, there is little knowledge about marijuana’s potential to cause lung cancer due to the difficulty in identifying and studying people who have smoked only marijuana (and not cigarettes).
Science Daily reports that the new study begins to address this question by comparing marijuana smoke and tobacco smoke in terms of toxicity to cells and DNA. The researchers exposed cultured animal cells and bacteria to condensed smoke samples from both marijuana and tobacco. There were distinct differences in the degree and type of toxicity elicited by marijuana and cigarette smoke.
They found that marijuana smoke caused significantly more damage to cells and DNA than tobacco smoke. However, tobacco smoke caused chromosome damage whereas marijuana did not.
