How does science explain the nocebo effect

Nocebo effect: media reports can trigger symptoms of illness

Expectation of harm can lead to symptoms / media should responsibly handle warnings of health risks


Media reports on substances that are thought to be hazardous to health can lead to sensitive people developing symptoms of illness, although there is no objective reason to do so. This is the result of a study that looked at the phenomenon of electromagnetic hypersensitivity. With these symptoms, those affected respond according to their own statements to electromagnetic waves such as cell phone radiation with complaints. They show physical reactions. With the help of magnetic resonance imaging, it can be seen that pain-processing brain regions are activated. "However, there is much to suggest that electromagnetic hypersensitivity is a so-called nocebo effect," explains Dr. Michael Witthöft from Johannes Gutenberg University Mainz (JGU). "Just the expectation of damage can actually trigger pain or discomfort, as we know it from placebo effects in the area of ​​pain-relieving effects." As the new study shows, media reports warning of health risks can induce or intensify nocebo effects in some people.

The media repeatedly report on health risks from electromagnetic fields (EMF) emanating from cell phones, cell phone masts, high-voltage lines and WiFi. People who, according to their own assessment, are sensitive to electromagnetic fields suffer from symptoms such as headaches, dizziness, burning skin or tingling, which they attribute to these emissions. There are those affected who, because of their electromagnetic hypersensitivity, withdraw from work and their social environment and in extreme cases even move to remote regions in order to avoid electrical systems entirely. "Tests have shown, however, that those affected could not distinguish whether they are actually exposed to electromagnetic fields and that their symptoms can be triggered by sham exposure as well as by real radiation," says Witthöft. The phenomenon known as the nocebo effect was first identified in drug studies. Test subjects showed side effects even though they had received a placebo rather than a drug.

In the investigations that Witthöft carried out together with G. James Rubin during a stay at King's College London, the 147 test subjects were initially shown a television report. Some of the test participants got to see a documentary on the broadcaster BBC One, which reported in some cases drastically about the health risks of cell phone and WiFi signals. The other part watched a BBC News report on Internet and cell phone data security. Then all test subjects were exposed to a fake WLAN signal, which they could assume to be real. Although there was no radiation at all, some test subjects developed the typical symptoms: 54 percent of the test subjects reported anxiety and anxiety, impaired concentration or tingling in their fingers, arms, legs and feet. Two participants ended the test prematurely because their symptoms were so severe that they no longer wanted to expose themselves to the supposed WLAN radiation. It was found that the symptoms were most pronounced in people with increased anxiety who were shown the documentary on the possible dangers of electromagnetic radiation before the sham exposure.

The study shows the extent to which sensational media reports, which often lack a scientific basis, can influence the health of large sections of the population. In all likelihood, the suggestion of health hazards not only works in the short term like a self-fulfilling prophecy, it can also lead in the long term to people believing themselves to be receptive and reacting to electrosmog with symptoms in corresponding situations. "It is imperative that science and the media work together more closely and that reports, for example on possible health risks of new technologies, are made as truthful as possible and to the best of our knowledge to the public," concluded Witthöft from the results of the study.