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Feeling Detoxified

Expectations, Effects, and Explanation


Giselle A. McCallum
Life Sciences
Quest University Canada
Annie Prud’homme-Genereux
Continuing Studies and Executive Education
Capilano University


This case study uses the example of ionic foot baths to examine how placebo treatments can affect our health and wellness. Inspired by a student’s real visit to a spa, the story begins with a description of the experience of an ionic foot bath, and then debunks the chemical explanation given by the spa as to how the foot bath works. The case then introduces placebo treatments and the placebo effect, and discusses how placebos can affect our health. The case was developed for use in an undergraduate general biology or neuroscience class, but it could also be used in a first-year chemistry class and would also be suitable for a course in human biology, general biology, the scientific method, critical thinking, health sciences, or consumer health.


  • Describe the causes of the phenomena observed during an ionic foot bath treatment.
  • Propose plausible hypotheses to explain the effects of the treatment on the human body.
  • Critically review claims about the mechanism of action of ionic foot baths.
  • Analyze data presented in tabular form from a research study.
  • Describe a placebo and its effects on the outcome of any medical treatment.


Ionic foot bath; electrolytic cell; experimental design; scientific literacy; critical thinking; evidence based medicine; placebo effect

Topical Areas

Scientific argumentation, Scientific method, Pseudoscience

Educational Level

High school, Undergraduate lower division



Type / Methods

Discussion, Interrupted



Subject Headings

Biology (General)  |   Neuroscience  |   Medicinal Chemistry  |   Medicine (General)  |   Psychology  |   Science (General)  |  

Date Posted


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Maryuri Roca
Chemistry Department
Lawrence University
Appleton, WI
Dear Giselle and Annie,

I used your case study in class to explain the different types of chemical reaction; these are dissolution, precipitation, redox, and gas-evolution; only neutralization was missing but that is ok, because that is an extensive topic by itself. The students volunteered to do the demonstration in the classroom (on a small scale so not much chlorine gas was produced) using stainless steel spoons, a battery and a bath of water with salt. We had a lot of fun. What I like about your case study is that, different from others case studies I have seen, this is the only one that had allowed me to cover a large body of material, which I think is one of the limitations of using case studies in science.

Thanks you so much for making this case available to us.