Asthma is an inflammatory condition that constricts the airways and causes increased mucus production. The lungs of an asthmatic are inflammed making them sensitive to a variety of triggers such as allergens or exercise. The presence of such triggers can cause further agitation leading to an asthma attack where the smooth muscles around the lungs constrict and the airways narrow resulting in wheezing and breathing difficulties.
It’s a seemingly paradoxical idea, smoking a plant to alleviate constriction of the airways, but it works. Of course smoking it is far from the cleanest method of delivery but its been known since 1973 that THC acts as a bronchodilator because of the work of Dr. Donald Tashkin. He and his team at UCLA investigated the effects of smoked cannabis and ingested THC on the lungs and found that both methods of intake dilated the airways.
Recently further investigation into THC’s effects on the lungs by French researchers determined it can inhibit the contraction of lungs, a mechanism that many current asthma medications utilize to alleviate the condition.
So how does this happen?
Much of the difficulties breathing caused by asthma can be attributed to the contraction of the smooth muscle surrounding the lungs. This contraction is caused by the neurotransmitter actetylcholine, the release of which is greatly reduced when the CB1 receptor is activated. This decrease in cholinergic transmission leads to decreased muscle contractions making for easier breathing for the patient.