Yeah like I'm going to smoke 20 joints every day like pack-a-day cigarette smokers... that is total BS.

Also cigarettes are bad for you not so much b/c of the tobacco itself (though it is potentially harmful) but more because of the way it is processed (even "all-natural" cigarettes are processed) to make it more absorbable.

I think that organic unprocessed marijuana is probably equal to organic unprocessed tobacco (though I have no research to back that up), but the marijuana you're going to smoke a lot less of than the tobacco, so it ends up being less harmful to your lungs.

Your brain... that's another story. There is research that says smoking up to five joints a week can benefit your brain, but any more than that, and your memory and attention will be negatively affected.