Mehmet Oz, America's doctor, is known for many things, but being a proponent of good science isn't one of them. Last summer, he was even dragged up to Capitol Hill and berated by senators for his bunk weight-loss prescriptions. "The scientific community is almost monolithic against you," Sen. Claire McCaskill admonished him.



Now comes more evidence of Oz's wizardry: according to the blog Retraction Watch, a key study that the TV doctor used to tout a green coffee bean extract for weight loss has been retracted. "The sponsors of the study cannot assure the validity of the data so we, Joe Vinson and Bryan Burnham, are retracting the paper," the journal's retraction notice reads.



Even before the retraction, the study had attracted a lot of scrutiny for being too weak and flawed to support any health claims, let alone weight loss wonders. The Federal Trade Commission had also settled a $3.5-million lawsuit with the supplement-makers for its false marketing and bad science. This from the FTC's September press release about the settlement:

The FTC charges that 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 GCA during the trial. When the lead investigator was unable to get the study published, the FTC says that AFS hired researchers Joe Vinson and Bryan Burnham at the University of Scranton to rewrite it.



Despite receiving conflicting data, Vinson, Burnham, and AFS never verified the authenticity of the information used in the study, according to the complaint. Despite the study’s flaws, AFS used it to falsely claim that GCA caused consumers to lose 17.7 pounds, 10.5 percent of body weight, and 16 percent of body fat with or without diet and exercise, in 22 weeks, the complaint alleges.



Although AFS played no part in featuring its study on The Dr. Oz Show, it took advantage of the publicity afterwards by issuing a press release highlighting the show. The release claimed that study subjects lost weight "without diet or exercise," even though subjects in the study were instructed to restrict their diet and increase their exercise, the FTC contends.

For more on how Dr. Oz can make these claims and still maintain his medical license, see here. To learn about the medical student who is trying to bring Dr. Oz down, see here.