Salty and umami tastes perception in hypertensive patients and its relationship to dietary sodium intake

Abstract

Background: Reducing the dietary sodium intake is one of the most important factors for controlling blood pressure. The changes that occur in perceiving saltiness and umami tastes in people with hypertension can be associated with the level of sodium intake. The aim of this study was to investigate the gustatory perception of these two tastes in patients with hypertension and its association with the level of dietary sodium consumed by these patients. Material and methods: In this case control study, 40 patients with hypertension and 40 healthy individuals were chosen. The blood pressure was measured for both groups. The power of perceiving saltiness and umami tastes was investigated using sodium chloride and monosodium glutamate solutions respectively both with concentrations of 200 mmol/lit. The individuals specified the power of each taste along a 10-number criterion. Based on the compounds of foods in Iran, the level of sodium consumed per day was calculated by food frequency questionnaire. The data were analyzed by Mann-Whitney, Pearson, Spearman tests. Results: The mean saltiness perception in the control and case group was 5/8 and 6/6 respectively(p < 0/05) and the mean umami perception the control and case group was 5/5 and 7/6 respectively (p < 0/05). There was an inverse relationship between the level of sodium intake and perceived intensity of saltiness perceptionin case group (p < 0.05).The level of sodium intake had no relationship with perceived intensity of umami taste in none of the groups (p > 0.05). There was also a direct relationship between blood pressure and intensity of perceiving umami taste in case group (p < 0.05).However, no significant relationship was found between blood pressure and the intensity of perceiving saltiness (p > 0.05). Conclusion: Perceived intensity of saltiness perception in case group higher than control group also perceived intensity of umami perception in case group higher than control group. With increase in the blood pressure, the power of perceiving saltiness and umami increases; with increase in sodium intake, saltiness perception diminishes, but umami perception is left unaffected.