Since tobacco smoking causes cancer, marijuana smoking must as well. Right? Wrong.

Marijuana decreases the risk of lung cancer. Marijuana does not cause chronic obstructive pulmonary disease (COPD). Thus, Pot is safer than cigarettes.

Professor emeritus of medicine at UCLA and one of the United States’ leading pulmonologists who has been studying weed and its effects on lungs for more than 30 years, Dr. Donald Tashkin once sought to prove pot causes lung cancer, but the evidence forced him to conclude that average weed smoking does not cause lung cancer or impair lung function:

“The smoke content of marijuana is very similar to that of tobacco. There is a higher concentrate of cancer-causing chemicals in marijuana tar, and it reaches the lungs before any other organ, so there is this idea that they are related in causing the same health issues of the lungs. But through my studies we failed to find any positive association [with cancer]. Instead, the association would be negative, between lung cancer and the use of marijuana. The likelihood is, that despite the fact that marijuana smoke contains carcinogens, we don’t see the same heightened risks of cancers that we see in tobacco.”