I've pondered on the very statement, and to me (though I have never smoked either) cigarettes seem worse for you than Marijuana.
The only negative HEALTH effect Marijuana has is it can strongly discombobulate your mind/actions. And yet, it has it's positives. Marijuana can ease depression, it can ease pain, and it can calm people.
Cigarettes on the other hand lead to lung cancer, heart cancer, brain damage, wrinkles, coughing, trouble breathing, really foul odors, and countless other things I can't even list.