Patients experience “nocebo effect” on low FODMAP diet

By Jason Clevenger

Most people are familiar with the “placebo effect,” where patients receiving an ineffectual treatment (such as a sugar pill) will report a perceived or actual improvement in symptoms. The Australian study described in this column related to a low FODMAP diet is an example of the opposite, called the “nocebo effect.” In this case, patients who were unknowingly following a completely gluten-free diet and should not have experienced any harm reported worsening of symptoms. Scientists have recognized that the expectations of a particular treatment, whether positive or negative, can have large effect on patient outcomes.