Researchers led by Madeline H. Meier of Arizona State University tracked the marijuana habits of 1,037 New Zealanders from birth to middle age to see what effect those habits have on some common measures of physical health, including lung function, systemic inflammation, cholesterol levels, blood pressure, body weight, blood sugar and dental health.
What they found was surprising: After controlling for other factors known to affect health, especially tobacco use and socioeconomic status, marijuana use had no negative effect on any measure of health, except for dental health. People who smoked more weed had a higher incidence of gum disease.
The cause is something of a mystery . . .