Not really random

Nutrition Action Healthletter, Jan-Feb, 2005

LeanSource, when combined with a program of a reduced calorie diet and moderate exercise, will result in two times more weight loss than exercise and diet alone," claims Life Time Fitness of Eden Prairie, Minnesota. How do they know? An "independent clinical study" proved it. That's "independent" as in a never-published sloppy test by someone with a vested interest in the outcome.

The key ingredient in LeanSource is 7-Keto, a form of the steroid hormone DHEA (dehydroepiandrosterone) that's produced by the Humanetics Corporation of Minneapolis. The chief medical and scientific director of Humanetics is John Zenk, who is also president and medical director of a clinical research firm called the Minnesota Applied Research Center.

Who did Life Time Fitness hire to carry out the "independent" test of LeanSource and its 7-Keto? Minnesota Applied Research Center.

Zenk "randomly" divided 54 overweight men and women into two groups, put them all on a diet and exercise program designed to help them lose eight to 12 pounds over eight weeks, and gave one group LeanSource and the other group placebo pills.

But Zenk's randomization failed to produce two similar groups. On average, the people in the LeanSource group started out three inches bigger around the waist and 23 pounds heavier than the people in the placebo group.

After eight weeks, the LeanSource takers had lost six pounds while the placebo takers had lost three pounds. The only reason that weight difference was (barely) statistically significant was that the placebo group lost much less weight than expected.

Of course, the people in the LeanSource group could have shed more pounds because they started out heavier. And the (leaner) people in the placebo group might have been less motivated to follow the diet.

Yet that didn't stop Zenk from claiming that LeanSource aids weight loss. Nor did it stop Life Time Fitness from claiming that LeanSource is "clinically proven" to help people double the pounds they lose.

That wasn't Zenk's only suspect study of a product from which he stood to profit.

FluidJoint is a dairy extract that his Humanetics company sells to relieve osteoarthritis pain. The clinical "proof" comes down to another Zenk study. (1) Once again, his randomization failed to produce similar groups. And even though the six-week study ended with the FluidJoint takers reporting the same level of symptoms as the placebo takers, Zenk concluded that "FluidJoint is safe and effective for continuous, long term use."

So much for independent research.

(1) Curr. Therapeutic Res. 63: 430, 2002.