TAS1R3 and TAS2R38 Polymorphisms Affect Sweet Taste Perception: An Observational Study on Healthy and Obese Subjects

Background: The inter-individual differences in taste perception find a possible rationale in genetic variations. We verified whether the presence of four different single nucleotide polymorphisms (SNPs) in genes encoding for bitter (TAS2R38; 145G > C; 785T > C) and sweet (TAS1R3; −1572C > T; −1266C > T) taste receptors influenced the recognition of the basic tastes. Furthermore, we tested if the allelic distribution of such SNPs varied according to BMI and whether the associations between SNPs and taste recognition were influenced by the presence of overweight/obesity. Methods: DNA of 85 overweight/obese patients and 57 normal weight volunteers was used to investigate the SNPs. For the taste test, filter paper strips were applied. Each of the basic tastes (sweet, sour, salty, bitter) plus pure rapeseed oil, and water were tested. Results: Individuals carrying the AV/AV diplotype of the TAS2R38 gene (A49P G/G and V262 T/T) were less sensitive to sweet taste recognition. These alterations remained significant after adjustment for gender and BMI. Moreover, a significant decrease in overall taste recognition associated with BMI and age was found. There was no significant difference in allelic distribution for the investigated polymorphisms between normal and overweight/obese patients. Conclusions: Our findings suggest that overall taste recognition depends on age and BMI. In the total population, the inter-individual ability to identify the sweet taste at different concentrations was related to the presence of at least one genetic variant for the bitter receptor gene but not to the BMI.

Senatore cappelli (Triticum turgidum ssp. durum) pasta: a study on the nutritional quality of whole grains and its physical form

Pasta is one of the components of the Mediterranean Diet, despite considerable attention given, its use is still debated. Several studies encouraged the consumption of whole grain because of its many properties and the positive association between refined carbohydrates and insulin resistance, by measuring the Glycaemic Index (GI), an indicator of the physiological effects of a carbohydrate meal. In this study, the GI and polyphenol content of Senatore Cappelli (Triticum turgidum ssp. durum) pasta were evaluated. Using spectrophotometric methods, total polyphenols and flavonoids were found to be 113.5 mg/100 g and 52.96 mg/100 g, respectively. To measure the GI, a standard assay was performed, and values of 47.9 ± 5.2 for long format pasta and 68.5 ± 4.6 for short format pasta were obtained. The present study confirms the presence of polyphenols and flavonoids in pasta Senatore Cappelli. The value of GI is influenced by the pasta shape. These informations could provide valuable data for practitioners preparing personalised diets.

A Pilot Cross-Sectional Study on Oral Health and Nutritional Status of Institutionalized Older Adults: A Focus on Sarcopenia

The global population aged over 60 will double by 2050. This pilot cross-sectional study aims at evaluating nutritional and oral health status and the prevalence of sarcopenia in older adults living in an Italian residential aged care facility. Thirty-two adults aged ≥65 years were included. Individual sociodemographic data and nutritional and oral health data were collected. For sarcopenia diagnosis, muscle mass, physical performance, muscle strength and anthropometric parameters were recorded. Participants underwent a nutritional screening and a dental examination. Mini Nutritional Assessment and masticatory mixing ability test were performed. The results showed that men recorded a hand strength significantly higher than that of women, 25.5 ± 7.2 Kg vs. 12.8 ± 5.9 Kg (p < 0.01), respectively. Gait speed test showed that only 20.8% of the participants had a speed of more than 0.8 m/s. A strong negative correlation between masticatory performance and the number of missing teeth was detected (r = -0.84, 95% C.I. [-0.92; -0.69], p < 0.01). Overall, a high percentage of institutionalized older adults were diagnosed as being sarcopenic. Poor oral health in older adults is a major general health problem as it may restrict both food selection and nutrient intake, representing a risk factor for sarcopenia, although longitudinal studies are needed to confirm this relationship.

The Influence of Age and Oral Health on Taste Perception in Older Adults: A Case-Control Study

Declining gustatory function, nutrition, and oral health are important elements of health in older adults that can affect the aging process. The aim of the present work was to investigate the effect of age and oral status on taste discrimination in two different groups of elderly subjects living either in an Italian residential institution (TG) or in the community (CG). A total of 90 subjects were enrolled in the study (58 CG vs. 32 TG). Masticatory performance (MP) was assessed using the two-color mixing ability test. Taste function was evaluated using cotton pads soaked with six taste stimuli (salty, acid, sweet, bitter, fat and water). A positive correlation between age and missing teeth (r = 0.51, C.I. [0.33; 0.65], p < 0.0001), and a negative correlation between age and MP (r = −0.39, C.I. [−0.56; −0.20], p < 0.001) were found. Moreover, significant differences for salty taste, between TG and CG were detected (p < 0.05). Significant differences in bitter taste sensitivity between subjects wearing removable and non-removable prosthesis were also determined (p < 0.05). In addition, significant gender differences and between males in TG and CG were identified (p < 0.05). The best understanding of the relationship between MP, taste sensitivity, and nutritional factors is a necessary criterion for the development of new therapeutic strategies to address more effectively the problems associated with malnutrition in elderly subjects.

A Study on the Relationship between Type 2 Diabetes and Taste Function in Patients with Good Glycemic Control

Type 2 diabetes mellitus (T2DM) has a very high impact on quality of life as it is characterized by disabling complications. There is little evidence about taste alterations in diabetes. Since many individual factors are involved in the onset of diabetes, the purpose of our study is to search a possible link between diabetes and individual taste function. Thirty-two participants with T2DM and 32 volunteers without T2DM (healthy controls) were recruited. Four concentrations of each of the four basic tastes (sweet, sour, salty, bitter), and pure rapeseed oil and water, were applied with cotton pads to the protruded tongue, immediately posterior to its first third, either to the left or right side. The results showed significant differences between groups in the ability to recognize sour, bitter, sweet, and water. Taste scores were lower in subjects with T2DM than in healthy controls, and an age-related decline in taste function was found. The taste function reduction associated with T2DM was not related to gender, disease duration, and glycemic control. In conclusion, it can be hypothesized that a general alteration of taste function can lead patients with type 2 diabetes to search for foods richer in sugars, as in a vicious circle, thus decreasing the likelihood of remission of diabetes mellitus.

Impact of Elderly Masticatory Performance on Nutritional Status: An Observational Study

Background and Objectives: Masticatory limitations on the dietary habits of edentulous subjects restrict their access to adequate nutrition, exposing them to a greater risk of protein energy malnutrition. The aim of this study is to verify the existence of an association between Masticatory Performance (MP) and nutritional changes in the elderly. Materials and Methods: 76 participants were enrolled. MP testing was performed using the two-color chewing gum mixing test. The system used reveals the extent to which the two differently colored chewing gums mix, and allows discrimination between different MPs. The assessment of the participants' nutritional statuses was carried out through a food interview. Anthropometric parameters were collected, and bioimpedance analysis was performed. Results: Mean MP was 0.448 ± 0.188. No statistically significant differences were detected between male and female subjects (p > 0.05). According to the Body Mass Index (BMI), obese patients had a lower MP than overweight and normal weight subjects (0.408 ± 0.225, 0.453 ± 0.169 and 0.486 ± 0.181, respectively). MP values were lower both in male and female subjects with a waist circumference above the threshold than those below it (0.455 ± 0.205 vs. 0.476 ± 0.110, respectively, in males and 0.447 ± 0.171 vs. 0.501 ± 0.138, respectively, in females). No relationship was noticed between MP and bioimpedance parameters (p > 0.05). Conclusions: A statistically significant relation was observed between MP and the number of missing teeth. A reduced MP could worsen nutritional parameters. A reduced MP did not seem to negatively affect bioimpedance parameters.

Erythrocyte membrane fluidity in mild cognitive impairment and Alzheimer's disease patients

Alzheimer's disease (AD) is the most common cause of dementia accounting for 60-70% of all demented cases and one of the leading sources of morbidity and mortality in the aging population. Most of the recent literature regards the relationship between plasma oxidative stress and AD, showing that markers of lipid peroxidation are significantly higher in AD and Mild Cognitive Impairment (MCI) patients with respect to control subjects. The increased generation of reactive oxygen species that occurs in AD may be also responsible for oxidative injury to erythrocyte membranes. Since erythrocyte membrane serves as a variable barrier to oxygen transport, changes in its stability can induce cellular hypoxia and the consequence brain tissue oxygenation. In this study, plasma oxygen radical absorbance capacity (ORAC) and erythrocyte membrane fluidity have been evaluated in control, MCI and AD patients. Moreover erythrocyte membrane acetylcholinesterase (AchE) activity has been measured in control and AD patients. Plasma ORAC significantly decreased in MCI and AD subjects with respect to the controls, while a decrease in erythrocyte membrane fluidity has been observed only in MCI patients. No significant differences were detected in erythrocyte AchE activity between control subjects and AD patients.

Modifications of taste sensitivity in cancer patients: a method for the evaluations of dysgeusia

PURPOSE

Taste changes due to chemotherapy may contribute to the high prevalence of malnutrition in cancer patients. It is believed that 50-70% of patients with cancer suffer from taste disorders. The aim of the present study was to analyze the taste alterations in patient population compared with that in controls, also in relation to gender. In this way, it could open to a new approach for a personalized diet to prevent and/or reduce taste alterations and malnutrition in cancer patients.

METHODS

Forty-five cancer patients undergoing chemotherapy were compared with healthy controls (n = 32). Taste function test was used to determine taste sensitivity. Different concentrations for each of the four basic tastes (salty, sweet, sour, bitter) and also fat and water tastes were evaluated.

RESULTS

A significant difference in taste sensitivity between patients and control group was found, in line with previous similar studies. As in the control group, taste perception in patients was better in females than in males, suggesting interaction effect between group and gender.

CONCLUSIONS

Coping strategies regarding subjective taste impairment should be provided since alterations in taste sensitivity influence food preferences and appetite. Clinicians could thus have the potential to underpin changes in dietary intake and consequently in nutritional status; understanding the extent of the contribution of each taste would help in the development of effective interventions in future. Consequently, patients can adopt appropriate appetizing strategies and, based on that, change their feeding habits.