Medical Marijuana & Asthma
Intuitively, asthmatic patients should carefully consider what they inhale, whether it be the pollen of the outdoors or cigarette smoke, and weight how likely it is to trigger an asthma attack. However, the role that the body's endocannabinoid system plays in modulating muscular contractions in the airway means that medical marijuana, even when inhaled, defies this logic.
CB1 receptors, the type that are found in the brain, also regulate the signaling of nerves in the lungs, and control the action of muscles that dilate and constrict the airways themselves. A study in the New England Journal of Medicine finds that a single dose of inhaled marijuana reduces airway resistance, or the effort needed to push air into the smallest vessels in the lungs.
A long-term study in the Journal for the American Medical Association similarly finds that low levels of even recreational marijuana use increases lung function, and the highest levels of use still saw no negative effect on lung capacity. This suggests that low-dose use of refined medical marijuana could modulate the symptoms of asthma, without the side effects of prednisone and other corticosteroids.