Secondhand Pot Smoke May Be as Bad as Tobacco

Everyone knows secondhand tobacco smoke is bad for you, but a new study claims secondhand marijuana smoke might actually be worse—at least where your heart is concerned, Medical Daily reports. In the study—published Wednesday in the Journal of the American Heart Association—researchers exposed rats to both types of smoke for one minute, which worsened the ability of the rats' blood vessels to widen and made the transportation of blood more difficult. It took the rats 90 minutes to recover from the effects of the pot smoke—three times longer than with the tobacco smoke. "These temporary problems can turn into long-term problems if exposures occur often enough and may increase the chances of developing hardened and clogged arteries,” the study's author, Matthew Springer, says in a press release.

Springer says this study could correct the current public perception that secondhand marijuana smoke is somehow less harmful than secondhand tobacco smoke. “We in public health have been telling the public to avoid secondhand tobacco smoke for years, but we don't tell them to avoid secondhand marijuana smoke, because until now we haven’t had evidence that it can be harmful,” he says. The results from the study indicate it's the actual smoke that's hurting the cardiovascular system, not active ingredients like nicotine or THC. "The broader message in the study may be a no-brainer," Forbes concludes. "Perhaps breathing in anything burning is just not very good for our hearts." (Marijuana could be an effective treatment for Alzheimer's.)