Association between the Cation Concentrations in Saliva and the Sensitivity and Preference of Salty Taste

Abstract

Controlling salt intake is important for maintaining health. Salt intake is expected to be influenced by both the recognition threshold for salty taste and the salt concentration that makes food taste better（preference concentration）; however, there are large individual differences in both, and the determining factors are unknown. Saliva components are expected to affect the salty taste threshold and preference. In this study, we analyzed the relationship between ion concentrations in saliva, salty taste perception, and self-reported preference and intake frequency for salty foods. We determined the recognition threshold and preference concentration for salt taste in 50 adult volunteers using paper filter strips that impregnated with NaCl. Sodium and potassium concentrations in resting and stimulated saliva were measured. Additionally, we administered a questionnaire to examine the degree of preference and subjective intake frequency for six salty foods. Sodium and potassium concentrations in the resting saliva of the low recognition threshold group were lower（3.12±1.90 mM）and higher（18.75±4.23 mM）, respectively, than those of the high recognition threshold group（4.88±3.55 and 15.34±3.55 mM, respectively）. Sodium concentration was also lowe（r3.22±2.03 mM）in the low-preference concentration group than in the high group（4.92±3.77 mM）, whereas potassium concentration was unrelated. Sodium concentration in the resting saliva had a significant positive correlation with preference concentration（r = 0.412, p < 0.05）and degree of preference（r = 0.417, p < 0.01）. Cation concentrations in resting saliva probably affect the salt taste threshold and preference. High consumption of salty foods likely leads to an increase in the resting saliva sodium concentration, which in turn increases preference for salt and may induce a vicious circle.