Study Behind the Green Coffee Bean Diet Craze Retracted

By Larry Husten

Edited by David G. Fairchild, MD, MPH, and Lorenzo Di Francesco, MD, FACP, FHM

The study that helped ignite the green coffee bean diet craze has been retracted. The details of the retraction and the full background of the story were reported on Retraction Watch.

The paper, published in Diabetes, Metabolic Syndrome and Obesity: Targets and Therapy, claimed to report results from a randomized, double-blind, placebo-controlled crossover study of green coffee bean extract. Following the study's publication, the Dr. Oz Show featured the product, and it soon became an international bestseller.

In September, the extract's manufacturer settled Federal Trade Commission charges of marketing the product based on this study. In a news release, the FTC said that "the study was so hopelessly flawed that no reliable conclusions could be drawn from it." According to the FTC: "The study's lead investigator repeatedly altered the weights and other key measurements of the subjects, changed the length of the trial, and misstated which subjects were taking the placebo or [green coffee antioxidant] during the trial."