Taste loss and aging.

BACKGROUND: There is a certain degree of "redundancy" in the taste system to maintain a stable whole-mouth taste sensation. However, as the compensatory redundancy of the taste system becomes inadequate to offset age related structural and functional deterioration, older adults exhibit heightened vulnerability to taste impairment. SUMMARY: Taste thresholds of older people have an upward trend. At suprathreshold levels, older people tend to be less sensitive to the changes of the concentration of tastants. The taste identification capacity also tends to decrease as aging. The extent of age-related taste loss varies in relation to specific taste qualities, tastant compounds, tastant concentrations (at the suprathreshold level), sites of stimulus presentation, and gender. Other factors, such as increased morbidity, increased administration of medications makes older people more vulnerable to perceptible/diagnosed taste loss. KEY MESSAGES: The extent of biological-aging-related taste loss is related to taste quality, compound, concentration, stimulation site and gender.