Not that this should surprise anyone who pays attention. Last summer, after the Federal Trade Commission had charged various individuals and companies with selling bogus weight-loss pills, Dr. Oz was called in to testify before a Senate committee about various claims he'd made about the pills (and other products) on his TV show, gushing about wonderful “miracle” pills or foods that allegedly made weight loss a snap, or prevented cancer, or some other goal which humanity has found difficult to achieve for thousands of years – so you should always be extra-skeptical of anyone who claims to have discovered an easy way to do this, especially when they're trying to sell it.
The British Medical Journal study has the rather lengthy title “Televised medical talk shows—what they recommend and the evidence to support their recommendations: a prospective observational study.”
Less than half
The researchers selected 40 random episodes of The Dr. Oz Show from 2013 (and another 40 random episodes from another show called The Doctors), and investigated any claims made in those shows. What did they discover?
The BMJ abstract says:
For recommendations in The Dr Oz Show, evidence supported 46%, contradicted 15%, and was not found for 39%.… On average, The Dr Oz Show had 12 recommendations per episode.
So less than half of Oz's recommendations had any actual evidence to support them. When the Washington Post discussed the BMJ study and Dr. Oz, it asked:
“has Oz, who often peddles miracle cures for weight loss and other maladies, mortgaged medical veracity for entertainment value? …. last month, a study he widely trumpeted lauding coffee bean weight-loss pills was retracted despite Oz’s assertions it could 'burn fat fast for anyone who wants to lose weight'.”
Oz, for his part, has admitted that sometimes he'll go overboard with using “flowery” language, though claims it's because he's “being passionate.”
Last June, when he testified before the Senate's Consumer Protection subcommittee, Sen. Claire McCaskill (D-Mo.) told him: “The scientific community is almost monolithic against you in terms of the efficacy of the three products that you call miracles …. When you call a product a miracle, and it's something you can buy, and it's something that gives people false hope, I don't understand why you need to go there.”
The meaning of "miracle"
That's when he reluctantly admitted to using “flowery” language. And, in all fairness, it is true that the words miraculous and miracle have long-since adopted everyday or colloquial meanings in addition to their original ones: a “miracle” originally meant anything literally miraculous and requiring supernatural or divine intervention, and it still sometimes has that meaning (especially when it's used in a religious context).
But “miracle” or “miraculous” also have come to colloquially mean “impressive” – pretty much any new techno-gadget or software suite will have marketing copy calling it “miraculous” somewhere. You can buy anything from miracle laundry detergents to miracle plant foods, with no literal belief in miracles required.
But those mundane "miracles" come from marketing writers, not a medical doctor and professional expert who, at least in theory, should be held to higher and more precise standards than everyday non-medical experts, at least when discussing medical matters.
The British Medical Journal, after studying Dr. Oz and similar shows, concluded that, “Recommendations made on medical talk shows often lack adequate information on specific benefits or the magnitude of the effects of these benefits. Approximately half of the recommendations have either no evidence or are contradicted by the best available evidence. Potential conflicts of interest are rarely addressed. The public should be skeptical about recommendations made on medical talk shows.”
In other words: just because Dr. Oz calls this particular pill or food extract a “miracle” (or even worth trying out) doesn't mean it actually is. Remember: investigators searching for actual evidence to back up Dr. Oz's various recommendations could only do so 46% of the time. That means more than half of Dr. Oz's claims either have no evidence to support them, or are directly contradicted by what evidence is available.