For those who did inhale infrequently, 20-year study shows minor pulmonary improvement
People who smoke marijuana for recreational or medical purposes might now breathe easier. Scientists report in the Jan. 11 Journal of the American Medical Association that occasional cannabis users don’t experience any loss of lung function.
In a 20-year study that included lung tests and a specific accounting of marijuana use, scientists also found that people who smoke more than 20 times a month and accumulate many years of use might have a slight drop in lung capacity over time. But the researchers are unsure of that finding since it was based on scant data.
The study is the longest ever conducted that measures cannabis smoking and lung function, uses standard lung measurements and includes thousands of volunteers, says Donald Tashkin, a pulmonologist at UCLA who wasn’t involved in the study. “That makes it important,” he says.
The data, he says, also suggest that marijuana is not a significant risk factor for chronic ob