It began with a tingling sensation, as if her foot was going to sleep.
Then numbness set in. It crept up to Elizabeth Gilley's calf and onto her thigh.
Over the next six months, the Mineral Wells woman grew weaker, her skin turned pale, and she could barely walk across the room without gasping for breath.
When she collapsed in 2007, Gilley was taken to a hospital.
"The doctor didn't know how I was still conscious," Gilley said.
At first, doctors told her that she had leukemia, but tests didn't confirm cancer. CT scans, MRIs and blood tests followed. Still Gilley was no closer to a diagnosis.
After a year of seeing doctor after doctor, she finally found out what was causing the symptoms, but she could hardly believe what the physician was telling her.
"Within five minutes of seeing him, he asked me if I wore denture cream," said Gilley, 26, who was forced to get dentures as a teenager after a genetic condition ruined her teeth. "I handed him the tube; he told me to stop using it."
By then the damage was done. Gilley could no longer walk, drive a car or get around without a wheelchair. Once an active young woman who had recently gotten married, she was rarely able to leave her home.
Gilley joined a growing number of people nationwide who have filed lawsuits alleging that the makers of some denture creams knew about the health risks associated with high levels of zinc in their products and did nothing about it. Fixodent and Super Poligrip are named in class-action lawsuits filed in Tennessee last year.
Gilley's suit against GlaxoSmithKline was recently filed in Philadelphia, where the manufacturer is located. About 20 other claimants have also filed suits in mass tort court in Pennsylvania.
GlaxoSmithKline declined to comment on the litigation. But on the Web site for Super Poligrip, the manufacturer addresses issues surrounding zinc.
Both GlaxoSmithKline, the maker of Poligrip and Super Poligrip, and Procter & Gamble, the maker of Fixodent, have said that their products contain zinc at levels recognized as safe. GlaxoSmithKline's label now states that there have been reports of serious health effects from increased zinc intake over a long period. But the company notes that small amounts swallowed during normal use are not harmful and that consumers should not apply the product more than once a day.
In addition, the Food and Drug Administration classifies the creams as medical devices and does not require zinc to be listed as an ingredient.
But dozens of people have been permanently disabled after using the cream for years, and at least one person has died, said Ed Blizzard of Houston, Gilley's attorney.
"I believe this is just the tip of the iceberg," he said. "I think a lot of people out there have neuropathy and don't know it could be connected to their dentures."
A debilitating disease
An estimated 35 million Americans use adhesives to secure their dentures, and most have no health problems associated with the creams. But some have developed severe neurological problems, they say, caused by ingesting dangerously high levels of zinc. Gilley developed neuropathy, which causes numbness, tingling and pain.
For years, the source of high zinc levels was a mystery. But recently researchers have observed a link between neurological problems and the use of denture cream, which contains zinc.
In 2008, researchers at the University of Texas Southwestern Medical Center reported on four young to middle-age patients who developed numbness, weakness and difficulty walking after ingesting high levels of zinc.
It's well-documented that too much zinc interferes with the absorption of copper into the bloodstream and can lead to neuropathy, said Dr. Sharon Nations, an associate professor of neurology at UT Southwestern.
The question was, Where was the zinc was coming from?
Nations suspected that denture cream might be the source after discovering that one of her patients had used the product a lot. When she learned that another had also used denture cream in large amounts, she tested a tube for zinc.
"We found it contained significant amounts," she said.
Since the patients were not getting zinc from vitamins, food or other sources, the researchers were left with one conclusion.
"The patients had no other source of the zinc," Nations said.
Those involved in the study were using on average two tubes of denture cream a week compared with the one tube every month to six weeks that dentists recommend.
When used as directed, denture creams are safe and adverse effects are very rare, according to the Consumer Healthcare Products Association, which represents the makers of over-the-counter medicines, vitamins and other products.
It is expected that consumers would ingest some zinc from denture cream, but the amounts would be small, the association said in a statement.
The amounts ingested would be no more than the amount in 6 ounces of ground beef, six oysters or a vitamin, according to Procter & Gamble.
Blizzard said denture wearers had no reason to cut back on denture cream because until recently there was no warning against using as much as they needed.
"In fact, on the box, it said that if the amount you're using doesn't work, use more," he said.
Left feeling numb
Gilley, who was not part of the study, did exactly that.
She used the cream as often as every two hours to keep the poorly fitted dentures in her mouth. Then 15 years old and a freshman in high school, she was embarrassed by the dentures, which became necessary after a genetic disorder damaged the enamel on her teeth. She was terrified that the dentures would fall out while she was eating in the school cafeteria.
She never imagined that the denture cream would lead to health problems a few years later.
Since learning about the link between her health problems and zinc, Gilley has stopped using the cream and gotten better-fitting dentures that stay in place without adhesives.
She has gradually regained some strength and moved from a wheelchair to a walker. But the numbness still makes it difficult to walk, and she rarely leaves the apartment she shares with her husband.
In general, patients who developed neurological problems after being exposed to excessive zinc have not shown dramatic improvements, Nations said.
"Their neurological problems don't improve; they just stop progressing," she said.
Gilley, who spends her time playing with her new puppy and watching television, is still optimistic despite waves of depression.
"I do hope I get full function back," she said. "That would be so great to live life again the way I used to."
JAN JARVIS, 817-390-7664