Saturday, January 7, 2012

How Real Is the Placebo Effect?

Did anyone happen to see the article "The Power of Nothing" in last month's New Yorker? (Here's a link to the abstract, but the full story is paywalled unfortunately.)

Very, very interesting -- and I'll return to its possible relevance for knee pain in a bit.

But first: what are placebos? Well, when we think of them, what usually comes to mind are sugar pills, or dummy pills of some sort, that contain no active medicinal ingredients. So in a clinical trial of Lipitor, researchers would test the actual Lipitor against a dummy pill, with subjects not knowing which they got -- real Lipitor or fake Lipitor. If there's a significant improvement in the Lipitor group versus the takers of the dummy pill, the drug company knows it's got a winner.

But what if you gave 100 people sugar pills that looked like Lipitor, told them they were Lipitor, and their cholesterol improved as much as if they were taking the real thing? Then you'd have a placebo effect at work.

Here are some interesting takeaways from the article:

* Some people respond better to placebos than others (and it may be for genetic reasons). Also some illnesses and afflictions are more amenable to the placebo response than others.

* A lieutenant colonel made an intriguing discovery during the Second World War, when 75% of gravely wounded soldiers -- men who, by all rights, should have been begging for pain relief -- declined morphine. He was astounded and concluded that expectations explained their seeming stoicism: because they had survived terrible attacks, they had positive outlooks. And so, our expectations can have a profound impact on how we heal.

* Why do placebos work? One explanation: the brain "produces its own pharmacy," secreting substances called endorphins that are chemically similar to opiates, like morphine. (In fact, in one study, patients who were told they would receive a painkiller -- whether they actually did or not -- experienced the same relief as those who secretly got between 6 and 8 milligrams of morphine.)

* The appearance of a placebo pill can matter: Larger pills produce stronger effects. Capsules work better than pills. Colored pills are more likely to relieve pain than white ones.

* The concept of "placebo" is a bit slippery: "For many people a placebo is just a sugar pill. For others, the definition includes the entire ritual of treatment, the complete interaction between doctor and patient."

One more thing: you'll be interested to know that one meta-study -- a study of many other studies -- found no evidence of a placebo effect with a couple of notable exceptions, such as "trials involving the treatment of pain."

Okay, what's all this have to do with lousy knees?

A few things, I'd submit:

(1) Certain knee pain treatments are considered effective by certain people probably because of the placebo effect.

To me, glucosamine is a prime example. As I explain in Saving My Knees, there's no reason it should work because the supplement you swallow gets ripped apart by your liver and little of it remains to circulate in the bloodstream. Yet I wish I had a dime for every comment I've read from a knee pain sufferer that goes like this: "Boy, when I don't take my glucosamine, I really feel it." To me this sounds like a classic placebo effect at work.

(2) Placebos have their limits.

They don't magically cure cancer. They don't even work for some people. Their efficacy seems to be highest for certain kinds of subjective ailments (and perception of pain is very subjective), and for a certain subset of the population.

(3) Expectations really matter!

While I'm not a believer exactly in "you create your own reality" (a certain amount of reality just happens, and you have to deal with it), the mind can be a powerful force. The placebo effect, in cases where it does work, shows that the mind can aid in healing or make pain more tolerable.

So instead of coming up with three reasons why your knees will never get better, come up with four reasons why they will. Instead of dwelling on what you can't do, figure out what you can -- celebrate it -- then figure out how you might be able to get from "can't do" to "can do" for what matters most to you, and sketch out a long-term plan to make it happen.

Put your brain's pharmacy to work -- for you.

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