You probably are getting as many daily E-mails as we are touting the great weight-loss miracle supplement, Green Coffee Bean extract. It’s a “fat burner” and it was recommended by Doctor Oz!
Three red flags there: “miracle,” “fat burner” and “Doctor Oz.” Don’t trust any of them. Doctor Oz is a Jekyll and Hyde Medutainer. He is a well-trained and qualified physician and can give excellent practical medical advice about half the time, but whenever he starts talking about food supplements and miracle diets, he immediately sets off the Quack-O-Meter, (or as Rachel Maddow calls it, the Bull Pucky Detector.”)
Scott Gravura discusses Oz’s Green Coffee Bean show and his faux “clinical trial” at the Science Based Medicine Blog. And Dr. Oz’s medical and quackademic sides are thoroughly discussed in this week’s New Yorker article by Michael Spector.
But do Green Coffee Beans work? Well, there is one paper reporting a study describing a trial where some weight loss occurred. The study is published in the on-line journal Diabetes, Metabolic Syndrome and Obesity Targets and Therapy. And the study has been carefully analyzed in the Science-Based Medicine Blog. The results are really not very convincing. According to Gravura’s detailed analysis:
- The authors are not clinicians; they are (gasp!) chemists!
- This is a tiny trial of 8 men and 8 women.
- The trial specifications were not published in advance (at clinicaltrials.gov), and they could have changed them after they got their results. We don’t even know what review board approved the ethics of the trial.
- The paper was funded by supplement manufacturer Applied Food Sciences, and carried out in Bangalore.
- The study claims that chlorogenic acids, the alleged active ingredients, are only available in green coffee beans. But in fact you will find these compounds in roast coffee as well.
- The study purports to be double blinded, but in fact the patients and the investigators could tell which dose they received because they took a different number of pills per day as “low dose” and “high dose.”
- Diet and calorie intake was assessed by patient recall, which is notoriously inaccurate.
- The actual data were inconclusive: the study gave the patients either a high dose, a lower dose or a placebo, with a “washout period” between the doses. The weight loss in one of these groups occurred during the washout period, suggesting that the coffee extract had little to do with it.
- The changes in each of the three diet periods were “modest,” and given the small sample size and lack of blinding, “the risk of bias is high.”
So if you listen to Doctor Oz, he gives good advice on actual medical issues, but as soon as he starts talking about “miracle” supplements and “fat burners,” don’t listen, even if you can hear him over the quacking of the Quack-O-Meter!