Marijuana Smoke as Damaging to Arteries as Tobacco Smoke
Written by Editor   
Wednesday, December 10, 2014 11:55 AM

Breathing secondhand marijuana smoke may be just as damaging to the heart and blood vessels as inhaling secondhand cigarette smoke, a small study in rats suggests.

The current study shows that "smoke is smoke."  When clinicians ask patients about smoking or exposure to secondhand smoke, they should also ask about "smoke from cigarettes, cigars, hookah, and marijuana, as well as wood fires and other sources of smoke from burning, dried-plant material."  The important message is that "inhaling smoke is not good for your heart, no matter what is burned to make the smoke, [and] patients with coronary heart disease should avoid exposure to smoke of any type." 

When the rats were exposed to marijuana smoke in a laboratory for half an hour, arterial flow-mediated dilation dropped by 50% to 70%.  Impairment in the ability of arteries to dilate was similar when the rats were exposed to smoke from marijuana with vs without tetrahydrocannabinol (THC), the primary psychoactive ingredient. Thus, "this is an effect of marijuana as a smoke source, not as a drug."