Netflix curbs tobacco use onscreen, but not pot. What's up with that?

This troubles Stanton Glantz, a professor of medicine at the University of California, San Francisco, who for years has studied the cardiovascular effects of tobacco smoke, and the effects of tobacco marketing — direct and indirect.

“Rating a film for 14 year olds that’s promoting substance abuse — it’s like the peak of risk,” he says. Glantz says although pot is widely regarded as holistic and harmless, compared to cigarettes, that’s not accurate.

“Marijuana is not harmless,” he says. “Secondhand marijuana smoke has the same kind of adverse effects on your blood vessels that smoking a cigarette does. Chemically it’s not all that different from cigarette smoke, except that the psychoactive agent is different.”