Procter & Gamble is currently involved in a class-action lawsuit that claims the zinc in its Fixodent denture adhesive can eventually lead to debilitating nerve damage for some users. And a new report from ABC News asks whether or not the company crossed an ethical line with regard to a report associating excessive exposure to zinc-containing denture cream with neurological disease.

The study, by researchers from the University of Texas, looked at four denture wearers with neurological disease. Its publication was held up for two years after receiving a very negative peer review from a dentist, who wrote that the findings were “little more than speculation” and that the authors “don’t understand the nature of the material they are writing about.”

Problem is, that dentist was actually a paid consultant for Procter & Gamble at the time he reviewed the report. And ABC News says he didn’t keep the two gigs separate:

In e-mails and documents… [the dentist] not only made recommendations that, according to the authors, led them to water down the study’s finding, but also sent draft reports of the study to Procter & Gamble.

“Please be circumspect because, as a reviewer, I’m not supposed to be passing an unpublished manuscript around,” he wrote in one e-mail to P&G about the study.

A professor at the Columbia University Medical School tells ABC that such behavior on the part of the dentist “is an outrage. This was wrong… That is a fundamental transgression of professional medical ethics and not to be allowed.”

Procter & Gamble, which has subsequently updated the Fixodent label to state that “”prolonged zinc intake may be linked to adverse health effects,” issued the following statement:

Procter & Gamble is committed to providing safe and effective products for all consumers… Fixodent is safe for use as directed, as supported by the experience of millions of consumers over many years. Our Fixodent formula has undergone extensive scientific testing, and we continuously monitor for its safe use. As with many of our products, we have updated the information we provide on our Fixodent packaging and our website over time to ensure consumers know how to use the product properly. Fixodent products and packaging meet all federal and local laws and regulations. The 2008 Nations article reported observations for four individuals. It was not a controlled clinical study. The authors of the article speculate about a “possible association” between chronic excessive use of zinc-containing denture adhesives and neurologic symptoms. In fact, we believe that no controlled clinical study has ever established a causal link. We know of no valid scientific evidence that using Fixodent as directed causes any ill health effects.

Fixodent: Can Excessive Use of Popular Denture Cream Cause Nerve Damage? [ABC News]

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