Denture Cream Can Cause Neurological Damage

Many, if not most, denture creams have caused neurological damage. Was a peer reviewer of an article exposing it guilty of attempting to prevent its publication? Or is he being smeared?

by Heidi Stevenson

23 April 2011

Some denture creams contain zinc because it provides a good hold. Unfortunately, excessive zinc can cause devastating nerve damage and many denture users have suffered grievously from it.

Many people have suffered from neurological losses that made them believe their bodies were failing. Symptoms developed over a period of time, with increasing weakness, strange sensations and numbness, and debilitation. Diagnosis has been exceedingly difficult, as doctors have not known what to look for. Excess zinc is not a common problem, other than in employees of businesses that use it in their products, such as paint factories.

The Denture Adhesive Problem

Zinc and copper are antagonists. Too much zinc interferes with copper metabolism, resulting in inadequate copper. Since excess zinc results in inadequate copper, it's difficult, if not impossible, to determine whether the deleterious effects result from the excess zinc or inadequate copper.

Whichever is the cause, the result can be severe. Bone marrow is suppressed and the spinal cord degenerates, resulting in nerve damage that is crippling.

It wasn't until the year 2000 that these people were finally diagnosed with copper deficiency. Until then, their symptoms of weakness, a spastic gait, numbness, and strange sensations went undiagnosed. Then, in 2007, Marco Spinazzi, MD, made the connection to denture cream. The next year, 2008, Sharon Nations, MD, and co-researchers at the Southwestern Medical Center at the University of Texas found four patients with symptoms of insufficient copper who were using denture cream.

Since then, many other patients have been diagnosed as having copper deficiency resulting from zinc in denture cream.

Last year, GlaxoSmithKline, the manufacturer of Polident, removed all zinc from their product. Many other makers of denture creams have also done so. Procter & Gamble, the makers of Fixodent, have refused to remove zinc from their product, stating:

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.

In all cases that have been cited so far, the problem has been excessive use of the denture adhesive. There is strong evidence that these cases involve only people whose dentures are ill fitting. It is known that poorly fitted dentures cause serious problems beyond the excess denture cream required to hold them in place. They also produce excess wear and tear on the mouth's bone structure, along with irritations that can become infected.

Did a Reviewer's Conflict of Interest Delay Publication of Journal Article?

Readers who are familiar with Gaia Health will know that I am not inclined to pull punches when it comes to issues of malfeasance in modern allopathic medicine. On starting to investigate this topic, my anticipation was to write a scathing tale about arrogance and misbehavior in medical research. But, it didn't turn out that way.

ABC did a scathing report about Kenneth Shay, a dentist who acted as a peer reviewer on a paper for the journal Neurology. They claimed that Shay had intentionally delayed publication of the study because of an association with the manufacturer of Fixodent, Procter & Gamble, and worse, they claimed that he did not admit to his association with the company. They also stated that Dr. Shay had secretly shown the paper to Procter & Gamble, which is considered a breach of ethics.

The one incontrovertibly true statement is the last one. Dr. Shay did secretly show P&G the paper, and he was fully aware that he should not have done so. If any harm came of the action, though, no one has commented to that effect.

Did Dr. Shay Hide His Association with P&G?

The claim that Dr. Shay didn't reveal his connection appears at first glance to be rather suspicious. However, there was no secret about his association with Procter & Gamble; it was listed on their website. This was Dr. Shay's first and last experience as a peer reviewer. He believed that the researchers had found him through the P&G website, as he is quoted here from Medscape:

I'm a dentist. Out of the blue I get an invitation from a journal that I've never heard of to review a paper about denture adhesives. I assumed they found me because of an article I had written about denture adhesives, which was on the Procter & Gamble Website. I figured the boiler plate that asked about conflicts of interest didn't apply to me because obviously they needed somebody who was an authority on denture adhesives, or they wouldn't have asked me. So, no, I did not explicitly say I had an affiliation with Procter and Gamble. I should have. I absolutely should have. But I didn't, and my rationale at the time was it was just so patently obvious how they got my name.

Did Dr. Shay Try to Delay Publication of the Paper?

Regarding the claim that Dr. Shay delayed publication of the article, there appears to be no truth. The ABC network wrote:

It [Dr. Nation's study] was delayed, according to its authors, because of a peer review by Dr. Kenneth Shay, a dentist, who lambasted the study and called the link between excessive use of denture cream and neurologic disease 'little more than speculation'.

In stark contrast, Sharon Nations, MD, one of the paper's authors, claims that neither she nor any of the other authors were contacted by ABC and that she was unaware they were doing a report until after it had aired. She stated:

No one from ABC News, no one from the show, spoke with me or Dr. Wolfe or Dr. Trivedi.

I can't speak to what he did or what evidence they had or who he might have had communications with. I know nothing about that. All I know is we got the reviews, we modified our answers, and a lot of the advice was very helpful. I think it made it a better paper because it helped us to explain things better. We addressed all the reviewers' advice, comments, and questions, and then we sent the article back to Neurology and they published it.

Criticisms are part of the peer review process. I welcomed them because we wanted the paper to be as complete and as accurate as possible.

Dr. Nations also said that the paper's publication was not delayed, and was, in fact, published in a typical period of time.

Was the Paper's Publication Delayed?

In truth, there appears to be nothing but an accusation from ABC to support the claim that Dr. Shay's actions were nefarious and that he delayed publication of a paper critical to the health of many people. There is no evidence cited by anyone, including ABC, to support the claim.

Dr. Shay appears to have been quite naive. In spite of his association with P&G, though, he doesn't seem to have done anything that actually caused any harm to anyone or delayed publication. On the surface, his actions appear suspicious, but at this point, I have seen nothing to support it.

It's also important to note that the paper itself was not a definitive study that proved cause and effect, nor did it claim to be. It was an examination of four patients who were harmed by eating excessive amounts of their denture adhesives. While their stories are tragic, that does not add up to a case of malfeasance on anyone's part, especially considering the fact htat Dr. Shay did not cause a delay in publication.

Denture Ingredients

The simple fact is that most denture adhesives contain some nasty ingredients, including:

• Polident Products: poly(methylvinylether/maleic acid), sodium-calcium mixed partial salt, petrolatum, red 30 aluminum lake, red 7 calcium lake, methylparaben, ethylparaben, PEG-90M, microcrystalline wax, polybutene. (Note: This list is not complete, and not all ingredients are included in all products.)
• Fixodent Products: carboxymethylcellulose sodium, polyvinyl alcohol-methyl acrylate copolymer (zinc is in this ingredient), mineral oil.

Zinc, the Nutrient

Zinc is a necessary nutrient, but like almost anything in excess, it can cause harm. Of course, deficiency is also dangerous, leading to symptoms such as loss of appetite and sex drive, growth retardation in children, slow wound healing, loss of taste or smell, toxemia in pregnancy, transverse lines and white spots on nails, and behavioral and sleep disturbances.

Zinc-rich foods include oysters, which contain exceptionally high levels. Other than that, high protein foods—such as beef, chicken, pork, crab, and lobster—tend to be the best sources. Zinc from non-meat sources tends to be more difficult to metabolize than from meat.

Like virtually all other nutrients, zinc acts in symbiosis with others. So, if you're a vegetarian who wants to assure adequate intake, be sure that your diet includes plenty of vitamins, C, E, and B6, and that you also have adequate magnesium, a substance in which a very large number of people are deficient.

Natural Denture Adhesives?

The interesting point to note is that natural denture adhesives generally include the polyvinyl acrylate ingredient—the one that contains zinc! Should this upset you? Frankly, if you have dentures that fit well, it shouldn't. Zinc is a nutrient. Taken in small doses, it's most appropriately deemed a supplement, not a poison.

As far as we know at this point—and we have no reason to believe otherwise—the people who have been harmed were using excessive amounts of denture adhesives. They should certainly not be blamed for it, since they were trying to deal with poorly fitted dentures. The harm that came to them is tragic, but the overall picture needs to be addressed.

Given a choice between proper use of a denture adhesive with zinc as an ingredient and one with ingredients like methylparaben, ethylparaben, polyubutene, and unnecessary colors added, which makes more sense? Frankly, the product produced by Fixodent strikes me as more appropriate.

There are others out there that contain more natural ingredients than Fixodent's, but in general, you'll find little difference. A. Vogel's denture adhesive called Secure contains almost exactly the same ingredients as Fixodent! Perhaps Vogel's is derived from higher quality ingredients. Frankly, I don't know.

The real point of this article is to set the record straight. Anyone who uses dentures must deal with them in the best manner possible. There generally are no easy answers. However, the recent scaremongering about zinc denture adhesives is unreasonable. Too much of anything can be harmful. People have died from drinking too much water.

The simple fact is that zinc is a necessary nutrient. When removing zinc from a product results in the addition of chemicals that are suspicious, a scaremongering campaign against products with zinc does denture wearers absolutely no favors.

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