“Evidence-based medicine”: a class discussion, with a caffeine lift!

Eileen Dombrowski
Theory of Knowledge banner

1507coffee(Originally posted on Activating TOK) Did you know that green coffee bean extract can help you lose weight? No? Me neither! Today, I’d like to propose a class discussion on thinking critically about media knowledge claims for products that yield fabulous (literally) medical benefits. The discussion is given a caffeine lift by a bite-sized example from a year ago – a story of fabulous claims and the corrective process of science.

I’m including this now because of Theo’s post last week (July 20, 2015):  “Evidence Based Medicine: WOK Language and AOK Natural Sciences.”  He outlined arguments given by scientists for replacing the term “evidence-based medicine” with the term “science-based medicine”:

  • to bring attention to common abuses of evidence (TOK justification),
  • to increase clarity of ideas (TOK concepts/language) and
  • to frame interpretation of data with larger scientific understanding (TOK methodology of the natural sciences).

As teachers, we can usually enter a topic easily enough through following arguments and linking them with our own understanding of TOK and our own experience. But when we take a topic to class, we don’t always teach in the same way we learn.  We often want to provide real life examples to get students started in their own thinking, and then guide them from the specific case toward general concepts and distinctions.

Green coffee beans: 3-part discussion

Purpose: This discussion is on knowledge claims based on (that is, “justified by”) apparent clinical trials, and on the way science works not by proving statements true but by knocking out knowledge claims that are demonstrably false (that is, “falsifying”). It reinforces the skills and awareness constant in TOK teaching: skills of applied critical thinking and awareness of broad knowledge questions.

Procedure: Nothing unusual. The activity involves students reading two short articles sequentially, with teacher-guided discussion.

1.  Article 1: The knowledge claims. 

Give students the article containing the knowledge claims for benefits of the extract from green coffee beans: “Dr. Oz: Lose Weight Effectively with Green Coffee Bean Extract” (June, 2014). Ask them to read the article closely and consider the following TOK questions:

  • What might make them accept the knowledge claims about green coffee beans as convincing? What apparent evidence is given?
  • What features of the claims of the website context might make them hesitate to accept the claims about the health benefits?
  • What questions would they like to have answered before they accept or reject the claims? How would they formulate these questions?

2.  Article 2:  The Retraction. 

Give students the  companion article from four months later on the retraction of the knowledge claims about the benefits of green coffee beans: “Authors retract green coffee bean diet paper touted by Dr. Oz”,(October 20, 2014). Ask them to read the article closely and consider the following TOK questions:

  • Is it a failure in science that false knowledge claims are ever made, or a success in science that they are weeded out, or both? What part does retraction play in the methods of science?
  • In face of people trying to sell fake remedies, what can individuals do to protect themselves?

3. Conclusion: larger knowledge issues.

Last, ensure that general TOK topics are raised and reinforced in discussion. This example of green coffee beans is trivial in itself, but can be used to draw out class discussion on questions in two categories – first on applied critical thinking and second on broad knowledge questions.

Applied critical thinking: With the example established, it takes only a few minutes more of discussion to stress the role of reading critically and the question above: “What can individuals do to protect themselves?” Ask students to generate their own general list of “red flags” that might alert a reader to possible bogus claims about medicines. (Ongoing TOK discussions are likely to be regularly building and applying such lists!)

Knowledge questions in the natural sciences (including medical research): It’s important to stand back from the particular example of green coffee beans to place it in context of knowledge questions for which it provides some illustration. These knowledge questions may have arisen already in discussion, but are useful to pull together before leaving the example:

  • In the methodology of the natural sciences, what is the role of peer review in scientific publication? Is it a perfect process? If not, what undermines it, and what strengthens it?
  • Does data ever “speak for itself”?   What is the difference between clinical data and knowledge?
  • It has often been said: “Science does not prove statements true beyond question, but does prove statements false”. Do you think this is a good description of scientific methodology?
  • A group of scientists critiquing problems in medical knowledge claims has insisted that the term “evidence-based medicine” should be replaced by the term “science-based medicine”?  Why does it matter to have “evidence” interpreted by scientists?

The final question above harks back to Theo’s blog post last week: “Evidence Based Medicine”. I recommend raising the distinction in class to illustrate the way that a shared understanding of terminology is important in the sciences (concepts/language). A critique of sloppy or dishonest use of terminology is, at the same time, an insistence on rigorous methodology.

Myself, I’d be tempted to end this class by offering students chocolate-covered coffee beans – with no claims about benefits to their health!

References and Further Reading

“Dr. Oz: Lose Weight Effectively with Green Coffee Bean Extract”. Pure Green Coffee. April 11, 2014. http://puregreencoffee.com/articles/dr-oz-green-coffee-bean-extract/

“Green Coffee Bean Manufacturer Settles FTC Charges of Pushing its Product Based on Results of “Seriously Flawed” Weight-Loss Study”, Federal Trade Commission: Protecting America’s Consumers. September 8, 2014. https://www.ftc.gov/news-events/press-releases/2014/09/green-coffee-bean-manufacturer-settles-ftc-charges-pushing-its

“Dr.Oz-endorsed diet pill study was bogus, researchers admit”, CBS News, October 20, 2014. http://www.cbsnews.com/news/dr-oz-endorsed-green-coffee-bean-diet-study-retracted/

Theo Dombrowski, “Evidence Based Medicine”: WOK Language and AOK Natural Sciences. Activating TOK, July 20, 2015. http://activatingtok.net/2015/07/20/evidence-based-medicine-wok-language-and-aok-natural-sciences/

Image: Green Coffee Beans by carllilo3070, Creative Commons via Pixabay 

Further TOK Support

Eileen Dombrowski, Lena Rotenberg, and Mimi Bick. Theory of Knowledge Course Book (in cooperation with the IB). Oxford University Press, 2013. https://global.oup.com/education/product/9780199129737/?region=international (For skills of critical thinking relevant in this activity, see the series of interchapters and the 2-page summary “A Guide to Evaluating Knowledge Claims”.)