Better Than They Feel?

Monday, July 15, 2013

Writing at The New Scientist, Alan Levinovitz introduces readers to the idea of the nocebo effect, noting along the way that it surfaced among the results of an Italian study of gluten intolerance:

[L]ast February[,] Slate's Darshak Sanghavi reported on an Italian study that confirmed the existence of gluten intolerance ("non-coeliac wheat sensitivity") as a third, "distinct clinical condition". In the study, one-third of patients who self-identified as gluten-intolerant did in fact experience symptom relief after adopting a gluten-free diet. Case closed, right? Pass the gluten-free pasta.

Not so fast. An important implication of the study is that two-thirds of people who think they are gluten intolerant really aren't. In light of this, the even-handed Sanghavi suggested that "patients convinced they have gluten intolerance might do well to also accept that their self-diagnosis may be wrong".
The article is a mixed bag, but does a good job of showing with a couple of examples how common cognitive errors can lead otherwise intelligent people into becoming convinced that something benign is actually harmful. (His other example is "Chinese restaurant syndrome", which I'd heard of and which sounded semiplausible to me, although I've never personally known anyone who claimed to suffer from it.)

-- CAV


Steve D said...

The nocebo effect is a good example of how cognitive errors can have read immediate physical consequences.

However, the possibility that reactions to gluten might be real but vary in intensity or that they may occur but not on a consistent basis or be tied to some other second factor are additional interpretations of the study he cites.

Also, I noticed that he gave no advice for getting past a nocebo effect or how you go about accepting that your self-diagnosis is wrong to the extent that you no longer suffer. Surely it must take more than a chuckle and a ‘oh well, I guess I was wrong all those decades, pass the donuts and pour me a beer’

The one person I know with Celiac’s disease was diagnosed years ago before it was fashionable; he didn’t even know of it until the doctor told him he had it. There is a test for it, so you would think that would be the first thing you would want to do if you thought you had the symptoms.

Gus Van Horn said...

I would say that your last paragraph is the best advice against the possibility of feeling sick due to a cognitive error or staying sick due to a half-cocked self-diagnosis.

There is the further problem that many non-scientists are ill-equipped to know the difference between gluten intolerance and other problems that might mimic it. They will have to navigate unfamiliar territory, and they might have to contend with disagreement among experts or even outright quackery along the way.