ABSTRACT
Aims: The salty taste modality is modulated by epithelial sodium channel (ENaC) and Transient Receptor Potential Vanniloid (TRPV1) ionic channel and more recently, the gastric hormone ghrelin and its signaling system are also thought to play a role. Taste perception plays an important role in modulating food preference, and intake and is partly determined by genetic variations in chemoreceptor genes. For the salty taste modality, no studies have yet identified any genetic determinants of salt taste in humans. Nevertheless, a single study has identified that common variations in genes encoding for TRPV1 (TRPV1) and ENaC (SCNN1B) may influence the perception of salt solutions in humans, while it is currently unknown whether it would be the same for ghrelin and its cognate receptor, GHSR. Therefore, the primary objective of this study was to investigate the association of Ghrelin Gly90Leu and GHSR Gly57Gly gene polymorphisms with individual’s saltiness intensity perception and pleasantness ratings. Study Design: A convenience sampling method was practiced in this study. The sampling was carried out among students between the age of 18–25. Place and Duration of Study: Universiti Tunku Abdul Rahman (UTAR), Perak campus between January to December, 2011. Methodology: We recruited 166 Malaysian university students (mean age: 20.33±1.68; 75 males, 91 females; 152 ethnic Chinese, 14 Indians; 113 normal weight, 53 overweight) by convenience sampling. Low and high sodium concentrations of foods, solutions and broths were tasted and rated for their perceived intensity and pleasantness using generalized Labeled Magnitude Scale and Labeled Affective Magnitude scale, respectively. Results: The minor allele frequencies (MAF) of Ghrelin Gly90Leu and GHSR Gly57Gly were 0.48 and 0.31, respectively. Only the perceived intensity of salted egg was significantly different among Ghrelin Gly90Leu genotypes, where the individuals with T318T and A318T genotypes rated the intensity significantly higher than those with the A318A genotype. Conclusion: In conclusion, Ghrelin Gly90Leu and GHSR Gly57Gly SNPs did not serve as markers for individual’s saltiness intensity perception and pleasantness ratings, at least among Malaysian subjects in this study. This suggests that the ghrelin signaling mechanism in modulating salty taste responsivity in inconclusive at the moment, as the positive findings in mice might not be translatable to humans.
ABSTRACT
Excessive sodium intake leading to hypertension, stroke, and stomach cancer is mainly caused by excess use of salt in cooking. This study was performed to estimate the salt content in school meals and to compare differences in perceptions related to sodium intake between students and staffs working for school meal service. We collected 382 dishes for food from 24 schools (9 elementary, 7 middle, 8 high schools) in Gyeonggi-do and salt content was calculated from salinity and weight of individual food. The average salt content from elementary, middle, and high school meals were 2.44 g, 3.96 g, and 5.87 g, respectively. The amount of salt provided from the school lunch alone was over 80% of the recommended daily salt intake by WHO. Noodles, stews, sauces, and soups were major sources of salt intake at dish group level, while the most salty dishes were sauces, kimchies, and stir-fried foods. Dietary knowledge and attitude related to sodium intake and consumption frequency of the salty dishes were surveyed with questionnaire in 798 students and 256 staffs working for school meal service. Compared with the staffs, the students perceived school meals salty and the proportions of students who thought school meals were salty increased with going up from elementary to high schools (P < 0.001). Among the students, middle and high school students showed significant propensity for the preference to one-dish meal, processed foods, eating much broth and dipping sauce or seasoning compared with the elementary students, although they had higher nutrition knowledge scores. These results proposed that monitoring salt content of school meals and consideration on the contents and education methods in school are needed to lower sodium intake.
Subject(s)
Humans , Cooking , Eating , Hypertension , Lunch , Meals , Surveys and Questionnaires , Salinity , Seasons , Sodium , Stomach Neoplasms , StrokeABSTRACT
BACKGROUND: Reducing salt intake is known to be an important factor for lowering blood pressure and preventing cardiovascular disease. Estimating amount of salt intake is a necessary step towards salt intake reduction. Self-reported saltiness of diet is a method most easily used to measure a patient's salt intake. The purpose of this study was to examine the value of self-reported saltiness of diet in measuring salt intake. METHODS: We used data from 681 participants who visited a health center at a university hospital between August 2003 and November 2005. A self-administered questionnaire was used to collect information on self-reported saltiness of diet, other dietary habits and lifestyle factors. Salt intake was estimated on the basis of 24-hour dietary recall with a computer-aided nutritional analysis program (CAN-Pro 2.0, Korean Nutrition Society). RESULTS: There was no statistically significant difference between the mean salt intake of the self-reported salty diet group (13.7 +/- 4.8 g/d) and the self-reported unsalty diet group (13.3 +/- 4.4 g/d). If we assume calculated salt intake as the gold standard, the sensitivity and specificity of self-reported saltiness were 39.5% and 63.6%, respectively. Salt intake was increased with higher calorie intake, frequency of eating breakfast (> or =5 times/wk) and being satiated with usual diet in men, but it was increased only with higher calorie intake in women. Regardless of actual salt intake, the group satiated with a usual diet tended to be in the group of self-reported salty diet. CONCLUSION: Self-reported saltiness of diet was not associated with actual salt intake. Further studies will be needed on the simpler and more objective tools to estimate salt intake.