A national study led by UCSF and the University of Alabama at Birmingham has found that low to moderate use of marijuana is less harmful to users’ lungs than exposure to tobacco.

The study collected data from more than 5,000 U.S. adults over 20+ years.

Researchers studied air flow rate – the speed in which a person can blow out air – and lung volume, the amount of air a person is capable of holding. It found that the more tobacco you use, the more loss you have. But with marijuana use, air flow rate increased rather than decreased with increased exposure to marijuana use – up to a certain level.

Researchers said that the amount of the two substances that is typically smoked played a significant role in the outcome; they found that tobacco users typically smoke 20 cigarettes a day while marijuana users only smoke two to three times a month.

Researchers could not determine if heavy marijuana use takes a toll on lungs similar to tobacco use.

The participants, who all volunteered, began as young, healthy adults 18 to 30 years old from four different communities: Oakland, Chicago, Minneapolis and Birmingham.



Photo Credit: BetacommandBot via Wikimedia Commons