PURPOSE: To obtain validated clinical values suitable for developing a gustatory function test, including umami taste, in a Korean population. MATERIALS AND METHODS: The investigation involved 297 participants with self-reported normal sense of taste and smell. Liquid solutions were used for the assessment of gustatory function. The test consisted of 30 taste solutions [six concentrations of five tastants (sweet, bitter, salty, sour, and umami)]. For evaluation of overall gustatory function, the number of detected or correctly recognized taste thresholds was combined to form a “taste score.” RESULTS: Mean values of each detection and recognition threshold for the five tastes in men were consistently lower than those of women. The 10th percentile of taste score for recognition was used as the cut-off value for distinguishing normogeusia from hypogeusia. In subgroup analysis, total taste score from recognition thresholds revealed a significant negative correlation with age, indicating lower scores for increasing age. Taste score for non-smokers was significantly higher than that of smokers, in terms of detection and recognition of taste sensitivities. CONCLUSION: This gustatory function test was easy to perform, affordable, and time-saving, with the capacity to self-produce and obtain reliable data. Gustatory function was more sensitive in young people, women, and non-smokers.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Child ; Female ; Humans ; Linear Models ; Male ; Middle Aged ; Republic of Korea ; Taste/*physiology ; Taste Threshold ; Young Adult

BACKGROUND AND OBJECTIVES: To investigate whether taste thresholds, as determined by electrogustometry (EGM) and chemical taste tests, differ by age and the severity of facial palsy in patients with Bell's palsy. SUBJECTS AND METHODS: This study included 29 patients diagnosed with Bell's palsy between January 2014 and May 2015 in our hospital. Patients were assorted into age groups and by severity of facial palsy, as determined by House-Brackmann Scale, and their taste thresholds were assessed by EGM and chemical taste tests. RESULTS: EGM showed that taste thresholds at four locations on the tongue and one location on the central soft palate, 1 cm from the palatine uvula, were significantly higher in Bell's palsy patients than in controls (p<0.05). In contrast, chemical taste tests showed no significant differences in taste thresholds between the two groups (p>0.05). The severity of facial palsy did not affect taste thresholds, as determined by both EGM and chemical taste tests (p>0.05). The overall mean electrical taste thresholds on EGM were higher in younger Bell's palsy patients than in healthy subjects, with the difference at the back-right area of the tongue differing significantly (p<0.05). In older individuals, however, no significant differences in taste thresholds were observed between Bell's palsy patients and healthy subjects (p>0.05). CONCLUSIONS: Electrical taste thresholds were higher in Bell's palsy patients than in controls. These differences were observed in younger, but not in older, individuals.
Bell Palsy* ; Facial Paralysis* ; Healthy Volunteers ; Humans ; Palate, Soft ; Taste Threshold* ; Tongue ; Uvula

PURPOSE: We recruited 118 women in their early 20's to examine the relationship between sodium intake and salty taste thresholds and preference. We also examined the association of salty taste preference with sodium-related dietary behaviors and major dishes contributing to sodium intake. METHODS: Daily sodium intake was estimated using a 127-item dish-frequency questionnaire. Salty taste thresholds and preference were measured using rating scales using water solution of NaCl and a self-administered questionnaire based on a Likert scale, respectively. RESULTS: Salty taste preference showed positive correlation with daily sodium intake and sodium intake-increasing behaviors, and inverse association with sodium intake-decreasing behaviors, including salt and soy sauce use at the table, the frequency of eating out and home delivery of foods, broth consumption of soup, stew or noodle soup, the use of ready-to-serve or processed foods, fresh vegetable intake, and the accommodating attitude toward bland food. Intake of sodium-contributing dishes, including ramen, spicy soft-tofu stew, radish kimchi, and dishes containing kimchi, also showed positive association with salty taste preference. Unexpectedly, detection and recognition thresholds of salty taste showed no association with salty taste preference, sodium intake, and sodium-related dietary behaviors. CONCLUSION: These findings suggest that salty taste preference could reflect sodium intake of individuals rather than thresholds of saltiness, and may be used as a simple and effective proxy for usual sodium intake.
Eating ; Female ; Humans ; Proxy ; Raphanus ; Sodium* ; Soy Foods ; Taste Threshold ; Vegetables ; Water ; Weights and Measures

BACKGROUND AND OBJECTIVES: Salt-taste threshold can influence salt appetite, and is thought to be another marker of sodium intake. Many studies have found an association between sodium intake and blood pressure. The aim of this study was to compare the salt-taste threshold and salt intake between hypertensive and normotensive groups. SUBJECTS AND METHOD: One hundred twenty volunteers (51 men and 69 women) who did not take antihypertensive medications were evaluated. First, a questionnaire, which included questions regarding demographic information and preference of salty taste, was conducted, and 24-hour ambulatory blood pressure was checked. Then salt taste threshold was measured by assessing the ability of the subjects to discern the taste of salt in graded solutions of saline. Lastly, 24-hour urinary sodium was measured in a 24-hour urine collection. RESULTS: The salt taste threshold and taste preference for salt were slightly higher in hypertensive group. There was slightly higher salt intake measured as 24-hour urinary sodium in the hypertensive group, compared with the normotensive group. However, there were no significant differences in salt taste threshold, preference of salty taste, and salt intake between the normotensive and the hypertensive groups. CONCLUSION: The threshold of salt taste was not related to sodium intake and hypertension status. These results suggest that the development of hypertension depends on the complex interaction of factors such as genes and environmental factors rather than sensory factors like taste threshold and taste preference.
Appetite ; Blood Pressure ; Humans ; Hypertension ; Male ; Sodium ; Sodium Chloride ; Taste Threshold* ; Urine Specimen Collection ; Volunteers

Excessive dietary salt intake is related to cardiovascular morbidity and mortality. Although dietary salt restriction is essential, it is difficult to achieve because of salt palatability. However, the association between salt perception or salt eating habit and actual salt intake remains uncertain. In this study, we recruited 74 healthy young individuals. We investigated their salt-eating habits by questionnaire and salt taste threshold through a rating scale that used serial dilution of a sodium chloride solution. Predicted 24-hr urinary salt excretions using Kawasaki's and Tanaka's equations estimated dietary salt intake. Participants' mean age was 35 yr, and 59.5% were male. Salt sense threshold did not show any relationship with actual salt intake and a salt-eating habit. However, those eating "salty" foods showed higher blood pressure (P for trend=0.048) and higher body mass index (BMI; P for trend=0.043). Moreover, a salty eating habit was a significant predictor for actual salt intake (regression coefficient [beta] for Kawasaki's equation 1.35, 95% confidence interval [CI] 10-2.69, P=0.048; beta for Tanaka's equation 0.66, 95% CI 0.01-1.31, P=0.047). In conclusion, a self-reported salt-eating habit, not salt taste threshold predicts actual salt intake.
Adult ; Algorithms ; Blood Pressure ; Body Mass Index ; Demography ; Female ; Habits ; Humans ; Linear Models ; Male ; Questionnaires ; Self Report ; Sodium Chloride, Dietary/*urine ; Taste Perception ; Taste Threshold ; Urine Specimen Collection

BACKGROUND AND OBJECTIVES: The aim of the study was to compare the gustatory function between age-matched men and women in Korean subjects. SUBJECTS AND METHOD: Healthy non-smoking volunteers without smell and taste disorders were investigated. Thirty-nine men and women of the same age group were evaluated for gustatory function. Whole mouth taste test was performed with successive solutions of sucrose, sodium chloride, citric acid, and quinine hydrochloride. The electrical taste thresholds were measured using an electrogustometer for four different sites in the oral cavity, i.e., both sides of anterior and posterior tongue. RESULTS: Female subjects had lower mean values of detection and recognition thresholds for all of the four tastes than male subjects, although these results did not reach statistical significance except for the detection threshold for salt and the recognition threshold for quinine. In electrogustometry, thresholds in the posterior tongue of glossopharyngeal nerve area were significantly higher for men than women. CONCLUSION: Men had higher taste threshold than women of the same age category. For additional information on the effects of gender and aging on taste thresholds, further studies including a large number of well-controlled subjects are essential.
Aging ; Citric Acid ; Female ; Glossopharyngeal Nerve ; Humans ; Male ; Mouth ; Quinine ; Smell ; Sodium Chloride ; Sucrose ; Taste Disorders ; Taste Threshold* ; Tongue ; Volunteers

BACKGROUND AND OBJECTIVES: The sense of taste is one of the most important human senses and plays a critical role in an individual's food preferences and the nutritional status. Proper gustatory function in older people is important for quality of life and enjoyment of food. The objectives of this study was to investigate the effect of aging on taste thresholds in Korean subjects. SUBJECTS AND METHOD: One hundred sixty normal volunteers without smell and taste disorders were investigated. Each subject was given a questionnaire for age, sex, status of smoking and medication. Then, a whole mouth taste test was performed with successive solutions of sucrose, sodium chloride, citric acid, and quinine hydrochloride. RESULTS: Older subjects (over 50 years) showed worse taste sensitivity compared with younger subjects (age 20-29 years). The detection thresholds of all four basic tastes and the recognition threshold of salty taste of elderly participants were significantly higher than those of young participants. CONCLUSION: Gustatory sensitivity was found to decrease with age. Especially, older subjects appeared to have a reduced perception of salt, which can alter eating habits, such as intake of more salty foods. Our data can provide preliminary normative values for future investigation of chemosensation in the Korean population.
Aged ; Aging ; Citric Acid ; Eating ; Food Preferences ; Humans ; Mouth ; Nutritional Status ; Quality of Life ; Surveys and Questionnaires ; Quinine ; Smell ; Smoke ; Smoking ; Sodium Chloride ; Sucrose ; Taste Disorders ; Taste Threshold

This study examined salty taste acuity and salty taste preference and sodium intake in relation to zinc nutritional status in 2 rural populations in Korea. And we also examined the main food contributors of their sodium intakes. We enrolled 218 adults (66 men and 152 women) from the Kangneung and Samcheok regions in Korea's Kangwon province in our study conducted from December 2011 to February 2012. Participants from each region were divided into 3 groups based on their serum zinc level (T1: lowest, T2: intermediate, T3: highest). We compared the salty taste acuity and preference, Na index (Dish Frequency Questionnaire for estimation of habitual sodium intake), blood pressure, and intakes of nutrients including sodium by 3 groups of serum zinc level. The results were as follows: a higher serum zinc level indicated a lower sodium intake and Na index (P < 0.05). The salty taste acuity was considerably higher for participants from the Kangneung region than those from the Samcheok region (P < 0.05). And the serum zinc level was significantly higher in participants from the Kangneung region than those from the Samcheok region (P < 0.05). We further divided the participants into 2 groups: those who consumed more zinc than the recommended intake (RI) and the others. We compared salty taste acuity and salty taste preference in the 2 groups. The salty taste threshold and palatable salty taste concentrations were lower for the group with a zinc intake above RI than for the group with zinc intake below the RI. However, the difference was not significant. This study confirms that taste function differs depending on zinc nutritional status. In future, it is required to a large-scale, long-term, prospective study on the correlation between zinc intake, serum zinc levels, and taste perception function and blood pressure.
Adult ; Blood Pressure ; Humans ; Korea ; Male ; Nutritional Status ; Surveys and Questionnaires ; Rural Population ; Sodium ; Taste Perception ; Taste Threshold ; Zinc

Recognition thresholds for NaCl, sucrose, citric acid, and caffeine, as well as the pleasant concentration of NaCl were assessed in 176 males and 312 females aged 50-88 years. Furthermore, relationships among taste sensitivities, taste preferences, and lifestyles were examined. The taste solutions were presented one after the other in ascending order using the sip-and-spit method. For the recognition thresholds of the 4 basic tastes, women perceived significantly lower concentrations than the men. However, the pleasant concentration of NaCl did not show a gender difference. Sensitivities for the 4 basic tastes did not decrease with age in the men, but they did significantly decrease with age for the women, especially for those above 70 years. For men, regular exercise was positively correlated with sensitivities for sour taste and bitter taste, and physical activity was negatively correlated with the pleasant concentrations of NaCl. For women, who had more physical activity, sensitivities for sweet taste and sour taste were lower compared to the others. This study indicates that the sensitivities for 4 basic tastes in water diminished with age, but pleasant salt concentration did not change with age. Further research on pleasant NaCl concentration is required to determine factors affecting salt preference, in order to decrease salt intake in the elderly.
Aged ; Caffeine ; Citric Acid ; Female ; Humans ; Life Style ; Male ; Motor Activity ; Sucrose ; Taste Perception ; Taste Threshold ; Water

BACKGROUND AND OBJECTIVES: Phenylthiocarbamide (PTC) and its chemically related compound,6-n-propylthiouracil (PROP), both produce a taste that is extremely bitter to some subjects (tasters) but tasteless or only slightly bitter to others (non-tasters). Earlier studies had used PTC, but most investigators have switched to PROP because of its several advantages. Recently, three single nucleotide polymorphisms in the TAS2R38 gene were identified and several studies have demonstrated a strong association between these genes with taster status. The aim of this study was to investigate the relationship between taste thresholds of PTC and PROP and their correlation with the TAS2R38 genotype. SUBJECTS AND METHOD: Seventy-five healthy normal volunteers were included. Taster status was determined using successive solutions of PTC and PROP, which comprised a total of 15 grades. All participants were genotyped for polymorphism of the TAS2R38 gene that affects taste sensitivity to PTC and PROP. RESULTS: PTC taste thresholds showed 96% correlation with the taste thresholds for PROP. Non-tasters defined by the PTC threshold test were the exactly the same with those identified as AVI (alanine, valine, isoleucine) homozygous, but taster status determined by the PROP threshold test showed 96% correlation with the genotypes. CONCLUSION: The PTC threshold test was more reliable for determining taste blindness than the PROP threshold test.
Ageusia ; Factor IX ; Genotype ; Humans ; Phenylthiourea ; Polymorphism, Single Nucleotide ; Research Personnel ; Taste Threshold ; Valine