The 62-year-old Briton contracted a rare neurological disorder caused by dental paste. The rare case is reported in BMJ Case Reports and briefly reported by Gizmodo.
The first symptoms were pain and numbness in the legs. The man's condition worsened for six months, with the result that he was forced to use a cane, and eventually stopped walking. Doctors identified a spinal cord injury caused by an acute lack of copper in the body. Deficiency of this metal affects bones, blood vessels, and the immune system, contributing to the loss of fine motor control of the limbs. In severe cases, this can lead to death.
Experts have determined what caused the lack of copper: excess zinc in the British body. Although zinc is an important trace mineral for humans, it can bind to the same receptors as copper ions, disrupting the chemical balance in cells.
It is reported that the patient used three to four tubes of zinc paste per week to care for dentures, which caused intoxication. The introduction of copper into the body stopped the development of the disease, but the Briton is now confined to a wheelchair.