bp's Science: the placebo effect (v.1)

One evening, I made chocolate cake with applesauce instead of oil. As can be imagined by any human with a fast metabolism and love for frosting, Jess insisted that such a manuver would be a mistake. Thus, he did not want me wasting a cake baking (which is rare in these parts) by adding applesauce. I understood his request, but my desire to find out if applesauce was just as good was too great. If applesauce could replace fatty oil, cake was to be my good friend for a long while.

So I added applesauce and the cake was good. So good that I knew Jess would never know I'd made the substitute. He got home to the surprise of chocolate cake.

"Have some!" I exclaimed, maybe a little over-giddy because it had turned out so good.

"You didn't put applesauce in it, did you?" he asked.

"No." I lied. I had to for the experiment to work. That is, I wanted to see if Jess' tastebuds could decipher that the oil was gone without him being swayed by the knowledge that it indeed was. I cut him a slice and in it went.

"This cake is really good. It's so moist. I think I'll have another piece," was Jess' conclusion.

So I gave him another and let out my secret, announcing to him much like Vizzinni did when he switched the glasses, "I did replace the oil with applesauce! But you couldn't tell."

"Really? The cake is good, but now that you mention it, I can tell. This cake is a little lighter than regular cake."

Enter the placebo effect. My example above isn't perfect but let me explain.

A placebo is defined as: an innocuous or inert medication; given as a pacifier or to the control group in experiments on the efficacy of a drug

The placebo effect is defined as: any effect that seems to be a consequence of administering a placebo; the change is usually beneficial and is assumed result from the person's faith in the treatment or preconceptions about what the experimental drug was supposed to do; pharmacologists were the first to talk about placebo effects but now the idea has been generalized to many situations having nothing to do with drugs

So why does a placebo work when it's actually nothing? Or in the cake case...why does Jess think his cake is just as delicious just because I've told him I've made no change (or reverse placebo). Well, in the cake case, maybe the cake was just delicious. But in real life, why do inert medications (in most instances the placebo is just a sugar tablet) tend to make people think the medication they were told they were taking was working (e.g., making their joint pain better or their heart burn lessened)? This tends to suggest to me that the power of the mind is great. Our brain has a power over our well-being. What do you think? What does the placebo effect suggest to you about human physiology?