Taste and Smell

Some age-related taste abnormalities lead to clinical complaints. Patients with burning mouth syndrome report a persistent burning sensation, usually localized to the front of the tongue, as well as distorted and persistent bad tastes. This condition occurs most commonly in postmenopausal women. Patients with burning mouth syndrome are less sensitive to threshold concentrations of sweet and sour, and tend to rate high concentrations of sugar and salt as less intense than do healthy controls. Burning mouth syndrome is one of the very few conditions that affect taste response to sweet. Both taste and pain pathways may contribute to burning mouth syndrome. One suggested cause has been dry mouth associated with hormonal changes at menopause.

Taste perception is dramatically influenced by salivary function. Taste cells require the presence of gustin, a compound in saliva, in order to develop normally. One component of gustin is zinc. Therefore low dietary levels of zinc, disruption of salivation, or drugs that bind zinc and prevent its use by the body may contribute to taste loss. Patients with disruption in zinc metabolism often experience loss of both taste and smell. Circumvallate papillae of such patients show a disruption of taste buds and taste pores, with obvious cell death. Both taste and smell have been restored in some patients by oral zinc supplementation.