Dear Dr. Gott: I read with interest about your reader with balance problems. Please research the side effects of Poligrip. Although the reader didn't mention wearing dentures, I'm passing on some information I found online regarding this issue and the lawsuit. Doctors say too much zinc drives down copper levels in the body, which sets up a chain reaction that affects the spinal cord, making it hard to walk and maintain balance. Small amounts of denture cream are safe, but those whose dentures are ill-fitting or use excessive amounts are at risk of developing zinc toxicity.

I have a friend with severe irreversible side effects because of denture creams. It's worth mentioning. Hope this helps.

Reply: More than 35 million people in the United States alone wear dentures. That translates into a potentially huge market for dental adhesives.

Procter & Gamble, which trademarks Fixodent, and Glaxo-SmithKline, which trademarks Poligrip, have had claims filed against them from residents of all 50 states and Washington, DC, regarding possible zinc-poisoning symptoms. Hypocupremia (a diminished concentration of copper in the blood) and hyperzincemia (a toxic overload of zinc) are the chief complaints presented.

The Food and Drug Administration does not require manufacturers to list ingredients on the labels of these two products because they fall into a class 1 category, meaning they are defined as "low-risk devices". The FDA categorises denture adhesives as medical devices intended to be applied to the base of a denture before the denture is inserted in a patient's mouth to improve denture retention and comfort under the Food, Drug and Cosmetic Act. While manufacturers are not required to submit marketing applications for most class 1 devices, they still must register and list the device with the agency and comply with other applicable FDA requirements.

These requirements include adverse event reporting, manufacturing controls and labeling that is neither false nor misleading. Monitoring is accomplished through mandatory and voluntary reporting protocols.

One of the manufacturers stands by its safety and efficacy statement, indicating their product is safe and effective when used as directed.

The vast majority of the zinc in the product remains in the adhesive and is not released into the mouth, and the potential for absorption through the gums is minimal. The key is moderation. Toxicity occurs with continued, chronic, excessive use, not when the products are used as directed.

Hypocupremia presents with spastic gait, prominent sensory ataxia (the inability to coordinate movement, poor balance, staggered ambulation) and lower-limb paresthesias. Known causes are prior gastric surgery, malabsorption and excess zinc ingestion.

Hyperzincemia manifests with spastic gait, anemia, prominent sensory ataxia, lower-limb paresthesias and neutropenia (an abnormal drop in the number of white blood cells in the blood).

Known factors are excess zinc ingestion, prior gastric surgery and malabsorption.

The gold standard for metal detection is a 24-hour urine analysis, but other testing may be ordered, as well.

Thank you for bringing this issue to light. It is one I neglected to mention in my original column but is certainly of great interest.

To provide more information, I am sending you a copy of my Health Report 'Consumer Tips on Medicines'. Other readers who would like a copy should send a self-addressed stamped number ten envelope and a $2 cheque or money order to Newsletter, PO Box 167, Wickliffe, Ohio 44092-0167. Be sure to mention the title or print an order form off my website at www.AskDrGottMD.com.

Dr. Peter H. Gott is a retired physician and the author of several books, including 'Live Longer, Live Better', 'Dr. Gott's No Flour, No Sugar Diet' and 'Dr. Gott's No Flour, No Sugar Cookbook', which are available at most bookstores or online. His website is www.AskDrGottMD.com. Contact him c/o United Media, 200 Madison Avenue, fourth floor, New York, New York 10016.