Читать книгу Placebo: Mind over Matter in Modern Medicine - Dylan Evans - Страница 22

The fact that trismus and inflammation can be affected by dummy treatments shows that the placebo response is not limited to subjective symptoms. Nevertheless, if these were the only objective signs that placebos could affect, it would be a hollow victory for the placebo response, falling far short of dramatic claims such as that cited at the beginning of this chapter. Inflammation and involuntary muscular spasms may well be objective signs of pathology, but they are not particularly dangerous problems. Is there any evidence that placebos can affect more serious conditions?

There is. Daniel Moerman, a medical anthropologist at the University of Michigan, has provided persuasive evidence that placebos can cure ulcers. Moerman began by gathering the results of seventy-one controlled trials of drugs for treating stomach ulcers. As usual, these studies did not include no-treatment groups, and so no individual trial provided direct evidence of a placebo response. By examining the studies together, however, Moerman was able to detect a pattern that did suggest that the placebos were having a powerful effect. Ingeniously, he compared those studies in which patients took two placebos a day to those in which patients took four placebos a day. In the first group, 33 per cent were healed, while in the second, 38 per cent were healed.¹⁴ This might not seem like a big difference, but it is statistically significant, and it has been replicated in another, more rigorous meta-analysis.¹⁵

Comparing two groups of patients taking different amounts of placebos is almost as good, scientifically speaking, as comparing a placebo group with a no-treatment group. The fact that those taking more placebos showed more improvement strongly suggests that the placebos were playing an active role in assisting recovery. Furthermore, the improvement was not just subjective. All the studies examined by Moerman checked whether the ulcers had really healed by using an endoscope to peer inside the patients’ stomachs.