In a bizarre case from the UK, a 62-year-old man developed a severe neurological disorder, and doctors learned it probably had something to with his dentures. Or at least, with the stuff keeping them in place.
Image: Science Museum, London. Wellcome Images.
Published on Monday in the online journal BMJ Case Reports, the man had described pain and numbness in his legs that had grown worse over six months. He started out just needing a cane, but eventually he could not even leave his house.
After discarding all the other possibilities, doctors ultimately diagnosed the man as suffering from copper deficiency myelopathy (or CDM). That's when your body isn't getting enough copper, a trace metal that, along with iron, aids in the formation of red blood cells. Copper also is part of what keeps bones, blood vessels and your immune system healthy. Symptoms of CDM are generally seen affecting the limbs, and causing a progressive loss of fine motor control.
But that wasn't the weird part. Ruling out the alternatives, doctors diagnosed the source of the issue as a zinc overload. The zinc, not usually even remotely toxic, was found in a denture fixative paste the man had been using for the last 15 years.
While zinc is also an essential trace nutrient, when you take it in excess, the element can mess with certain aspects of your body's chemical balance. For instance, zinc ions can start to be absorbed by the same receptors which normally attract copper ions. This has reportedly been associated with deformation in the spinal cord.
All signs point to the culprit being the man's weekly habit of using two to four tubes of denture fixative paste, which likely blew through zinc's recommended dietary allowance of just 15mg a day. Doctors found that after the zinc-paste use had stopped and additional copper was administered to the patient, the progression of his disease was halted. Unfortunately for this gent, he hasn't recovered fully and still requires a wheelchair.
Could this happen to you? Unlikely, as long you aren't also snarfing down zinc-laden paste. If you are in a situation where you need a tighter grip on those false choppers, there are zinc-free alternatives these days. Even the US Food and Drug Administration says that the zinc in your adhesive paste can be bad — it published a 2011 statement recommending manufacturers to label their products with warnings against overuse.
Zinc has also gained a reputation as something that could relieve symptoms of the common cold, but the science behind those claims is pretty sketchy. So best to keep calm and keep eating getting your zinc from dietary sources, such as milk and red meat.