AMERICAN HEART ASSOCIATION
DALLAS, July 27, 2016 -- Rats' blood vessels took at least three times longer to recover function after only a minute of breathing second-hand marijuana smoke, compared to recovery after a minute of breathing second-hand 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 second-hand marijuana smoke for one minute, their arteries carried blood less efficiently for at least 90 minutes, whereas similar exposure to second-hand 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 second-hand marijuana smoke at levels similar to real-world second-hand tobacco smoke.
"Arteries of rats and humans are similar in how they respond to second-hand tobacco smoke, so the response of rat arteries to second-hand marijuana smoke is likely to reflect how human arteries might respond," Springer said.