This is Part 2 of an occasional series of posts on common understandings of cannabis.

Myth 4: THC kills brain cells

This myth originated with a now discredited study of three monkeys, claiming to show brain abnormalities after dosing with high amounts of cannabis. Subsequent, larger studies with monkeys showed no physical changes to monkeys dosed daily for a year. Studies with human users in Costa Rica and Jamaica confirmed this.

Sources: NORML; SRI International; National Center for Toxicological Research


Myth 5: Smoking pot is safer than tobacco

A study by the British Lung Foundation found that pot smoke can cause a number of medical conditions, including chronic coughing, acute bronchitis and lung cancer. The study found that those who smoke both pot and tobacco had a higher rate of lung cancer than those who smoked tobacco alone. While a joint might seem far less damaging than a pack of cigarettes, pot smokers tend to inhale deeply and hold the smoke longer, exposing their lungs to 4-5 times more dangerous particles with each puff.

Sources: Aphria; British Lung Foundation


Myth 6: Doctors are opposed to legalization

In a study conducted in 2014, a majority of physicians surveyed by WebMD said they believed that marijuana should be legalized for medical purposes. In 2015, a poll by SERMO, the top social network exclusively for doctors, reported that 68 percent of US physicians support legalized cannabis.

Sources: WebMD; SERMO