unSpun_ Finding Facts in a World of Disinformation - Brooks Jackson [51]
CASE STUDY: Is Cold-Eeze “Clinically Proven?”
EVEN A GOOD STUDY FROM A REPUTABLE SOURCE CAN BE MISLEADING, if the results can’t be replicated. If you’ve ever gotten the sniffles and shopped for a drugstore cold remedy, you’ve probably noticed a product called Cold-Eeze, which contains a zinc compound and claims to be “clinically proven to cut colds by nearly half.” Science has proven this zinc stuff works! Or has it? A close look at the evidence shows that the Cold-Eeze claim—indeed, the entire company—is based largely on a single study from 1996. But several other studies have produced starkly different results.
The original study, still cited on the Cold-Eeze website as we write this, was done at the Cleveland Clinic Foundation by Dr. Michael Macknin. That study and Macknin’s many subsequent news interviews sent Cold-Eeze flying off drugstore shelves. He told Barbara Walters on ABC’s 20/20 in January 1997 that he “got goose bumps” when he tabulated the data, and added, “here was something that actually seemed like it was helping the common cold, and nothing had really worked like this before.” The price of stock in the Quigley Corporation, which sells Cold-Eeze, soared, going from about $2 a share before the study was published to a high of $37 at the time of the 20/20 broadcast.
The first study seemed solid enough. It was published in a reputable, peer-reviewed journal, Annals of Internal Medicine. And it was a double-blind study: forty-nine subjects got the Cold-Eeze lozenges, fifty got a placebo, and neither the subjects nor the persons dispensing the lozenges knew which was which until the time came to tally the results. But when Macknin conducted a second study, of 249 suburban Cleveland students in grades one through twelve, he found that the kids who received the placebo got over colds just as quickly as those getting Cold-Eeze. The lozenges “were not effective in treating cold symptoms in children and adolescents,” said the report, published in The Journal of the American Medical Association in June 1998. It added that further research was needed “to clarify what role, if any, zinc may play in treating cold symptoms.” Quigley’s stock plunged. The company had actually paid for Macknin’s second study, but it doesn’t display that one on its website.
Since that 1996 study that launched Cold-Eeze sales, the evidence has continued to be mixed. Over the years some scientific studies have found that zinc gluconate (the featured ingredient of Cold-Eeze) seemed to reduce the duration and severity of cold symptoms, but several other scientific studies have found no such effect. The National Institutes of Health have concluded: “Additional research is needed to determine whether zinc compounds have any effect on the common cold.” Zinc might work, or it might not.
So Cold-Eeze turns out to be another brand built on spin, like Listerine. In 1999, the Federal Trade Commission accused Quigley of false advertising for claiming on the QVC shopping network that its lozenges could actually prevent colds. The FTC said Quigley had no reasonable evidence to support such claims, and Quigley settled the case by agreeing to stop making them. Also false, in our view, is the company’s biggest selling point, its claim that Cold-Eeze is “clinically proven” to cut cold symptoms by 42 percent. The best the company can say truthfully is that Cold-Eeze has been clinically tested, with inconclusive results.
Non-Evidence: Linus Pauling and Bruce Willis
We’ve shown that anecdotes can mislead