Tricks of the trade: "clinically proven"

Nutrition Action Healthletter, Jan-Feb, 2005 by David Schardt

The two weight-loss supplements look and cost about the same. But one brand is "clinically proven" to melt off pounds. The other label offers no proof.

Which one are you going to buy?

"A clinically proven claim in advertising is an effective sales pitch," says Michelle Rusk of the Federal Trade Commission. But "companies that make a claim like that should have competent and reliable scientific evidence to back it up, in most cases with well-controlled clinical studies."

They should have good studies on people ... but they don't have to.

Take Lichtwer Pharma, manufacturer of Kwai, the world's most popular brand of garlic pills. At the same time it was splashing "clinically proven to lower cholesterol" in big, bold lettering on its packages, the company was hiding the results of a human study in the U.S. that showed that Kwai didn't lower cholesterol.

The study's authors eventually pressured Lichtwer to publish the results. (1) (Kwai packages now say "clinically proven to support cardiovascular health," a vague claim that requires no hard evidence and isn't as easy to disprove.)

Here are a few more examples of how "clinically proven" may mean virtually anything ... including nothing.

(1) Arch. Intern. Med. 158: 1189, 1998.