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.

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.

General Decrease of Taste Sensitivity Is Related to Increase of BMI: A Simple Method to Monitor Eating Behavior.

BACKGROUND AND OBJECTIVES: The present study was conducted to evaluate the relationship between taste identification ability and body mass index (BMI) by studying the response to the administration of different taste stimuli to both sides of the tongue in three different groups of subjects. SUBJECTS AND METHODS: Thirty healthy normal-weight volunteers, 19 healthy overweight subjects, and 22 obese subjects were enrolled. For each subject, the lateralization Oldfield score, body weight, height, and blood pressure were determined. The taste test is based on filter paper strips soaked with 4 taste stimuli presented at different concentrations to evoke 4 basic taste qualities (salty, sour, sweet, and bitter); pure rapeseed oil and water were also administered to evoke fat and neutral taste qualities. The stimuli were applied to each side of the protruded tongue. Subjects were asked to identify the taste from a list of eight descriptions according to a multiple choice paradigm. RESULTS: The results showed a general lowering of taste sensitivity with the increase of BMI, except for the taste of fat with rapeseed oil as the stimulus. Other variables affecting taste sensitivity are age (negative association), gender (women generally show higher sensitivity), and taste stimuli concentration (positive association). CONCLUSIONS: Our findings could provide important insights into how new therapies could be designed for weight loss and long-term weight maintenance and how diets could be planned combining the correct caloric and nutritional supply with individual taste preferences.

A very low calorie ketogenic diet improves weight loss and quality of life in patients with adjustable gastric banding.

BACKGROUND: Often, in severe obesity, diet and physical activity are not enough to achieve a healthy BMI. Bariatric surgical approach, in particular laparoscopic adjustable gastric banding (LAGB), has encouraging results in terms of weight loss and resolution of obesity-related comorbidities. However, several months after LAGB, some patients are enable to lose weight anymore and don't tolerate a further calibration because of its collateral effects (excessive sense of fullness, heartburn, regurgitation and vomiting). AIM: The aim of this study is to identify the potential role of high protein-low carbohydrate ketogenic diet (KD) in managing weight loss in patients who underwent gastric banding and didn't lose weight anymore. METHODS: 50 patients underwent LAGB between January 2010 and December 2013. In twenty patients (GROUP A) we observed a stop in weight loss so we divided this patients into two groups. One group (group A1: 10 patients) continued to follow a LCD low calorie diet and underwent a further calibration; the other group (group A2: 10 patients) started to follow a KD for the next 8 weeks. RESULTS: Both group resumed a significant weight loss, however group A1 patients reported collateral effects due to calibration and a higher Impact of Weight on Quality of Life - Lite (IWQOL-Lite) that correlates with a lower quality of life than patients following KD. CONCLUSIONS: KD can improve the weight loss and quality of life in patients who underwent LAGB and failed at losing more weight allowing a weight loss comparable to that obtained with a further calibration and it is useful to avoid drastic calibrations and their collateral effects. KEY WORDS: Laparoscopic adjustable gastric binding, Quality of life, Very low calory ketogenic binding.

Effects of in vitro supplementation with Syzygium cumini (L.) on platelets from subjects affected by diabetes mellitus.

The aim of this study was to assess the in vitro effects of Syzygium cumini (L.) (Sc) incubation on platelets from patients with diabetes, in order to test its efficacy as a potential adjuvant therapy. This study was performed on 77 patients with diabetes [29 in good (DMgc) and 48 in poor glycemic control (DMpc)] and 85 controls. In patients, platelets were analyzed at recruitment and after in vitro Sc incubation (final concentration of 200 µg/ml for 3 hours at 37 °C), whereas in controls only basal evaluation was performed. Lipoperoxide and nitric oxide (NO) levels, superoxide dismutase (SOD) and Na(+)/K(+) ATPase activities, total antioxidant capacity (TAC), and membrane fluidity tested by anisotropy of fluorescent probes 1-(4-trimethylaminophenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH) and 1-6-phenyl-1,3,5-hexatriene (DPH) were determined. Collagen-induced platelet aggregation was also evaluated. In vitro Sc activity counteracts oxidative damage, by improving platelet function through augmented membrane fluidity and Na(+)/K(+) ATPase activity; it also enhances antioxidant system functionality by increasing NO levels, SOD activity, and TAC and by decreasing lipoperoxide levels both in whole samples and in DMgc and DMpc. In addition, a slight tendency towards collagen-induced platelet aggregation decrease after Sc was observed. However, all these parameters, even after improvement, did not reach the levels of control subjects. Our results suggest that Sc may have a preventive and protective effect in oxidative damage progression associated with diabetes mellitus and its complications. If our data will be confirmed, Sc supplementation might become a further tool in the management of this disease, especially in view of its easy availability, safety, low cost, and absence of side effects.