No one other than the Drug Czar publishes more misleading headlines about marijuana than Reuters news service. Heck, the Drug Czar even gets his blogging ideas [8] from them.
Via NORML [9], just look at these two recent Reuters headlines regarding recent marijuana research:
All of this sounds very disturbing, of course, but as is always the case with scary marijuana headlines, there turns out to be far more to the story and far less for marijuana users to worry about. In this case, both studies relied on small samples of obscenely heavy marijuana users (up to 350 joints per week!).
Let me be the first to concede that if someone smokes marijuana all day every day, there is something wrong with them. They may be treating a medical and/or psychological condition and their use may even be understandable under some unusual circumstance. But these are not the people we should study if we want to know the effects of marijuana. The lessons we learn from observing them won't apply to anyone but them.
Beyond all of that, neither of these studies even shows what the headline said. They just didn't. Sarah Baldauf at U.S. News & World Report [12] helpfully points out that the "shrinking brain" study researchers didn't know what size the participants' brains were before initiating marijuana use. It's possible that people with a smaller hippocampus and amygdala are more likely to become compulsive marijuana users, and that the drug doesn’t change brain size at all. Brain size is also a deeply flawed measure of intelligence anyway. In sum, the story isn't news, it's nonsense.
As for the marijuana-heart disease link, the study didn’t address whether the subjects actually had heart disease. Its conclusions were based on heightened levels of a protein that's associated with heart disease. It means nothing, even if you leave aside the fact that the subjects of the study smoked an unbelievable 78-350 joints per week.
In fairness to Reuters, both stories included a strong counterpoint from MPP [13]'s Bruce Mirkin, arguing that the absurdly high marijuana consumption of the study participants rendered any conclusions meaningless. Nonetheless, we should not be grateful simply because a reformer got a quote in a story that should never have been published.
We could go on all day about bad things that marijuana "might cause," "could lead to," or "may be associated with," but none of that means a thing unless it's actually true. What is true, and will always be true, is that the war on marijuana users harms far more people than marijuana ever could.