Oh noes, more 0.9bar = 1 again?
Mathematically speaking, it's not. Practically speaking, it is.
Bringing infinitesimal and calculus only allow you to throw out something if it IS zero. That is, math works a bit like circular logic (just like a lot of physics)--that is, you allow something to go to 0 or infinity because that produce the expected result, not because it is true. If you want to stick with calculus though, try looking up "asymptotes". Now do a 1/n, where n->infinity. There you go, something that is infinitely close to 0, and yet is not 0.
As for the new age crap/spiritual healing stuff.. Personally I think a lot of it is BS. But placebo effect IS a psychological effect, and it can be stronger than most anticipated. Most doctors agree that stress can kill. Well.. if some whacky placebo effect keeps you from being stressed, would that not in turn drop your chance of getting a heart attack? Who knows, maybe you'll even feel stronger and start going out for exercise, which helps even more!
And don't mess with acupuncture. Anything dealing with the nerves has adverse effects, and may help/kill you easily. Afterall, a KO in a boxing ring is nothing more than extensive trauma to the brain that sends nasty signals to the nerves. So stimulating the nervous system itself could very well produce very strong result.