Peer Reviewer Accused of Conflict in Fixodent Zinc Poisoning Study

February 23, 2011, 5:00PM. By Gordon Gibb

New York, NYFrom a public relations standpoint, it couldn't be any worse. Not only does Fixodent denture adhesive still contain zinc (which has been found to harm people when used in excessive amounts), it has been discovered that the release of important research that may have succeeded in spreading the word more quickly was unnecessarily delayed under questionable circumstances.

What's more, the US Food and Drug Administration (FDA) is coming under fire for sitting on valuable adverse reaction data.

Investigative reporter Chris Cuomo held up a thick binder containing more than 360 adverse reaction reports involving Fixodent zinc poisoning while appearing on ABC World News Tonight with Diane Sawyer February 8 and noted the FDA would not agree to talk with the media news outlet about the issue. Fixodent manufacturer Proctor & Gamble also declined an on-camera interview.

Cuomo reveals that the much-publicized study on four patients that first brought to light the denture cream zinc poisoning issue was completed in 2006. However, publication was delayed two years, Cuomo reports, allegedly because of the involvement of a peer-reviewer.

Cuomo revealed on ABC World News Tonight with Diane Sawyer, as well as on Good Morning America that Dr. Kenneth Shay, in authoring the peer review for publication, was critical of the study and noted that the authors "don't understand the nature of the material they are writing about."

However, ABC News discovered that Shay failed to disclose that he was also a paid consultant for Procter & Gamble—the manufacturer of Fixodent—which put him in a conflict of interest.

David Rothman, a medical ethicist at Columbia University, appeared on camera and told Cuomo that the conduct was "a fundamental transgression of professional medical ethics and not to be allowed."

Shay is also accused of having shared draft copies of the study with the Fixodent manufacturer. In one e-mail obtained by ABC News, Shay wrote to Procter & Gamble, "Please be circumspect because as a reviewer I'm not supposed to be passing an unpublished manuscript around."

Rothman called it an outrage. "It's a fundamental breach of confidentiality. The guy simply broke all rules of conduct."

In a phone interview with ABC News, Shay defended his review and asserted that the study contained "objective shortcomings." However, in 2009, the manufacturer attached a warning label to Fixodent denture adhesive cautioning that prolonged zinc intake could be linked to adverse health effects.

What those effects were—Fixodent zinc poisoning—were not specified on the label.

Procter & Gamble told ABC News in a statement that it was not aware of any valid scientific evidence that using Fixodent as directed causes any ill health effects. However, such a statement appears to ignore the propensity for a growing number of Americans to use Fixodent in larger amounts than the directions call for, in order to anchor loose or ill-fitting dentures.

As the US continues to languish in a slow economy and denture wearers have even fewer resources with which to update their dentures, the likelihood of continued use of products such as Fixodent in excessive amounts is palpable, together with the risk for denture adhesive zinc poisoning.

Mark Jacoby told ABC News that his problems started with a tingling in his fingers more than 10 years ago. Doctors finally identified his problem as neuropathy caused by excessive levels of zinc, which deplete healthy levels of copper in the body. Jacoby is now 41 and must use a walker to get around.

He has long since stopped using Fixodent. But the damage to his body has already been done by Fixodent zinc poisoning.