Don't get too excited about the new study which the media is misleadingly claiming shows a link between marijuana smoking and reduced bladder cancer risk. The study actually found that smoking marijuana may be less likely to cause bladder cancer than cigarettes. While this is certainly an interesting finding there were no non-smokers included in this study, which is disappointing, because it doesn't let us ground the findings in the greater population. Essentially, what the study shows is that marijuana smoke is slightly less harmful for you in one area of risk for men of concern than tobacco.
Did anyone's opinions on medical or recreational marijuana use change in the slightest based on any of those studies up there? No, probably not, because marijuana legalization, like the drug war encompassing the issue, has become an ideological struggle much more so than a moral one. Morality requires reason, which is why ideology is so much safer. This has become a disagreement in which one side (the anti-marijuana one) willingly ignores the science and research being done into the issue; this makes them impossible to reason with. Continuing to implement our nation's policies with clear disregard to how the world actually operates will only harm ourselves.
Has any finding really influence how anyone thought about marijuana whatsoever? Does any scientific finding? Is the government even listening to these studies? It certainly seems like the government wishes to remain ambivalent on the situation as they have repeatedly refused to allow more scientific research into marijuana, and ignore scientific pleadings to reduce marijuana to a lower schedule drug. Especially painful is the White House's official FAQ on marijuana, which reads like an unenthused high school argumentative paper more than a FAQ on scientific analysis. This is actually similar to most groups that disagree with marijuana legalization. Skip to the section about how marijuana is harmful because it can be as bad as cigarettes. It's painful. Real scientific analysis on drugs are hard to come by though, as they are dangerous to produce.
In 2009 David Nutt, a member of the British Advisory Council on the Misuse of Drugs, conducted a study on the comparative harms of various kinds of drugs, which is summarized here. Because he actually analyzed the comparative dangers of drugs and put forth the radical idea that perhaps the penalties for drug use should reflect the harm they cause, he was fired from his post and forced to apologize. So much for conducting scientific analysis.
I had a friend who once said that the best thing about weed being illegal was that it got almost everyone who tried it or knew people who did it to question the government. Because what is commonly said about the substance and what it is actually like, are so different, the only conclusion is that you've been lied to. This article nicely summarizes what anyone who has cared to look into the issue has found: that all of the harm you've heard is exaggerated, and that even though it is likely not good for you, marijuana is no worse than plenty of other legal substances.
If we don't allow scientific consensus to shape our policy then we deny basic reason. Despite what one may personally think about marijuana we cannot hope to understand it truly until we fully scientifically analyze it.
And then there's this.