Is It the THC That Makes It Mellower?

A staple of anti-pot propaganda in recent years has been the implication that marijuana poses more of a cancer risk than tobacco because a joint contains more carcinogens than a cigarette. One problem with this scare tactic is that it ignores patterns of use: The typical pot smoker lights up far less often than the typical cigarette smoker. Another problem is that epidemiological research has not verified an elevated cancer risk among people who smoke only marijuana. A research review in the October 18 issue of Harm Reduction Journal suggests one possible reason for this (aside from dosage): THC, marijuana's main psychoactive ingredient, seems to reduce the effect of carcinogens in pot smoke, whereas nicotine seems to enhance the effect of carcinogens in tobacco smoke.