Lead researchers have retracted a 2012 Diabetes, Metabolic Syndrome and Obesity: Targets and Therapy study which supposedly found that green coffee bean extract helped participants lose 18 pounds over 22 weeks on average. Mehmet Oz promoted the diet supplement, Green Coffee Antioxidant, on his show, The Dr. Oz Show, and was later questioned about the product during a Senate hearing.

Earlier this year, the U.S. Federal Trade Commission (FTC) settled charges against supplement manufacturer Applied Food Sciences (AFS), alleging that the company used the results of a flawed study to make baseless weightloss claims about its product. In the complaint, FTC alleged that AFS funded an Indian researcher to conduct the study, then hired other researchers to rewrite the results.

The latter researchers have now retracted the study in a short statement in the publishing journal: “The sponsors of this study cannot assure the validity of the data so we, Joe Vinson and Bryan Burnham, are retracting the paper.” In a later joint statement, the researchers reportedly said, “We retracted the paper because of an error in one of (the) data points on the BMI graph and because, as the FTC pointed out to us, there was inadequate disclosure of diet restrictions on the subjects and inadequate disclosure of the blinding procedures for the supplements given the subjects.” Among other allegations, FTC had argued that the rewriting researchers never reviewed the raw data despite noting several discrepancies in the data sets they received. Further details about the FTC settlement appear in Issue 32 of this Report. See CNN, October 24, 2014.