Study: Smoking Marijuana Not Linked with Lung Damage by Maia Szalavitz in TIME.
Marijuana does not impair lung function—at least not in the doses inhaled by the majority of users, according to the largest and longest study ever to consider the issue, which was published today in the Journal of the American Medical Association.
Researchers working on a long-term study of risk factors for cardiovascular disease (the Coronary Artery Risk Development in Young Adults or CARDIA study) tested the lung function of 5115 young adults over the course of 20 years, starting in 1985 when they were aged 18 to 30. [...]
While tobacco smokers showed the expected drop in lung function over time, the new research found that marijuana smoke had unexpected and apparently positive effects. Low to moderate users actually showed increased lung capacity compared to nonsmokers on two tests, known as FEV1 and FVC. FEV1 is the amount of air someone breathes out in the first second after taking the deepest possible breath; FVC is the total volume of air exhaled after the deepest inhalation.
“FEV1 and FVC both actually increased with moderate and occasional use of marijuana,” says Dr. Mark Pletcher, associate professor of epidemiology and biostatistics at the University of California, San Francisco and the lead author of the study.
Not that it really matters from a legalization point of view. Even if marijuana was damaging to lungs, that wouldn’t in any way justify prohibition. But this study makes prohibition “arguments” look even more pathetic.