A minute of secondhand marijuana smoke may damage blood vessels

http://www.eurekalert.org/pub_releases/2016-07/aha-amo072216.php

Public Release: 27-Jul-2016
A minute of secondhand marijuana smoke may damage blood vessels
American Heart Association Rapid Access Journal Report
American Heart Association

Rats' blood vessels took at least three times longer to recover function after only a minute of breathing secondhand marijuana smoke, compared to recovery after a minute of breathing secondhand tobacco smoke, according to new research in Journal of the American Heart Association, the Open Access Journal of the American Heart Association/American Stroke Association.

When rats inhaled secondhand marijuana smoke for one minute, their arteries carried blood less efficiently for at least 90 minutes, whereas similar exposure to secondhand tobacco smoke caused blood vessel impairment that recovered within 30 minutes.

"While the effect is temporary for both cigarette and marijuana 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," said Matthew Springer, Ph.D., study senior author and professor of medicine at the University of California, San Francisco's Division of Cardiology.

Blood vessel function was examined in rats before and after exposure to secondhand marijuana smoke at levels similar to real-world secondhand tobacco smoke.

"Arteries of rats and humans are similar in how they respond to secondhand tobacco smoke, so the response of rat arteries to secondhand marijuana smoke is likely to reflect how human arteries might respond," Springer said.

Researchers also found the mere burning of the plant material appears responsible for the impaired blood vessels, not chemicals like nicotine and tetrahydrocannabinol (THC), the psychoactive ingredient in marijuana, nor rolling paper.

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tags: drug use, drug abuse