A new whole-mouth gustatory test procedure - II. Effects of aging, gender and smoking

Taste detection and recognition thresholds for the 4 basic tastes were measured in 670 healthy subjects using a new whole-mouth method in which test solutions of the 4 basic tastes were diluted 1 : 1 with distilled water successively in 13 steps. The taste thresholds were measured by spraying a 1 ml aliquot of solution into the mouth, starting with the lowest concentration, and asking the subject to swallow and note if a taste was detected and, if so, which one. The mouth was rinsed with distilled water only between different taste test solutions. Multiple comparison analysis showed a clear age-related increase in thresholds for salty, sour and bitter tastes for subjects in their eighth decade of life. From the third decade onwards, female subjects had significantly lower thresholds compared to males for sour taste in about half of the age groups and for salty and bitter tastes in some age groups. In contrast, for 18- and 19-year-old subjects, the gustatory thresholds of male subjects were lower than those of female subjects. Regarding smoking, male smokers in their third decade had significantly higher thresholds for bitter taste compared to male non-smokers in this age group.