Factors related to taste sensitivity in elderly: cross-sectional findings from SONIC study

Taste Function in Adult Humans from Lean Condition to Stage II Obesity: Interactions with Biochemical Regulators, Dietary Habits, and Clinical Aspects

Differences in gustatory sensitivity, nutritional habits, circulating levels of modulators, anthropometric measures, and metabolic assays may be involved in overweight (OW) development. The present study aimed at evaluating the differences in these aspects between 39 OW (19 female; mean age = 53.51 ± 11.17), 18 stage I (11 female; mean age = 54.3 ± 13.1 years), and 20 II (10 female; mean age = 54.5 ± 11.9) obesity participants when compared with 60 lean subjects (LS; 29 female; mean age = 54.04 ± 10.27). Participants were evaluated based on taste function scores, nutritional habits, levels of modulators (leptin, insulin, ghrelin, and glucose), and bioelectrical impedance analysis measurements. Significant reductions in total and subtests taste scores were found between LS and stage I and II obesity participants. Significant reductions in total and all subtests taste scores were found between OW and stage II obesity participants. Together with the progressive increase in plasmatic leptin levels, insulin, and serum glucose, decrease in plasmatic ghrelin levels, and changes in anthropometric measures and nutritional habits along with body mass index, these data for the first time demonstrated that taste sensitivity, biochemical regulators, and food habits play a parallel, concurring role along the stages evolving to obesity.

NIH Workshop Report: sensory nutrition and disease

In November 2019, the NIH held the "Sensory Nutrition and Disease" workshop to challenge multidisciplinary researchers working at the interface of sensory science, food science, psychology, neuroscience, nutrition, and health sciences to explore how chemosensation influences dietary choice and health. This report summarizes deliberations of the workshop, as well as follow-up discussion in the wake of the current pandemic. Three topics were addressed: A) the need to optimize human chemosensory testing and assessment, B) the plasticity of chemosensory systems, and C) the interplay of chemosensory signals, cognitive signals, dietary intake, and metabolism. Several ways to advance sensory nutrition research emerged from the workshop: 1) refining methods to measure chemosensation in large cohort studies and validating measures that reflect perception of complex chemosensations relevant to dietary choice; 2) characterizing interindividual differences in chemosensory function and how they affect ingestive behaviors, health, and disease risk; 3) defining circuit-level organization and function that link and interact with gustatory, olfactory, homeostatic, visceral, and cognitive systems; and 4) discovering new ligands for chemosensory receptors (e.g., those produced by the microbiome) and cataloging cell types expressing these receptors. Several of these priorities were made more urgent by the current pandemic because infection with sudden acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the ensuing coronavirus disease of 2019 has direct short- and perhaps long-term effects on flavor perception. There is increasing evidence of functional interactions between the chemosensory and nutritional sciences. Better characterization of this interface is expected to yield insights to promote health, mitigate disease risk, and guide nutrition policy.

Associations of Taste Perception with Tobacco Smoking, Marijuana Use, and Weight Status in the National Health and Nutrition Examination Survey

Habitual smoking of tobacco and marijuana can lead to weight changes and poor diet quality. These effects may be caused by taste changes related to smoking and marijuana use. This study examined the associations among taste perceptions of a bitterant (quinine) and salt, tobacco and marijuana use, and weight status. We conducted a cross-sectional analysis of adults who responded to the National Health and Nutrition Examination Survey in 2013-2014. Participants (n = 2808; female = 51.7%) were adults ≥40 years with an average body mass index (BMI) of 29.6 kg/m2. Participants completed whole mouth and tongue tip assessments of bitter (quinine) and salty (NaCl) tastes, and questionnaires on demographics, cigarette, tobacco, and drug use. Measured height and weight were used to calculate BMI. Compared with never smokers, current smokers reported increased bitter ratings. Smoking status was not associated with salty taste intensity ratings after adjustment for demographic variables. Current marijuana users reported lower tongue tip quine ratings than never users. Among current smokers, current marijuana users had lower whole mouth quinine ratings than never users. Taste perception for salt and quinine for current and former smokers as well as marijuana smokers varied in whole mouth and tongue tip assessment. Changes in taste perception among cigarette smokers and marijuana consumers may be clinically relevant to address to improve diet and weight status.

A klotho gene single nucleotide polymorphism is associated with the onset of stroke and plasma klotho concentration

Klotho protects against development of multiple age-related disorders, including cardiovascular diseases. We assessed whether a human klotho single nucleotide polymorphism (SNP) rs650439 is associated with the onset of stroke in hypertensive patients and plasma klotho concentration in the general population. Five hundred and twenty-three patients with hypertension were analyzed for both the presence of rs650439 and onset of stroke. We found that hypertensive patients with the TT genotype of rs650439 (n=52) had a higher incidence of stroke than those with AT (n=257) and AA (n=214) genotypes. Multivariate analysis indicated that the TT genotype was the only risk factor associated with increased incidence of stroke. Plasma klotho concentrations were measured in a general population (age=70±1 years) to assess the association between rs650439 and plasma klotho concentration. A significant trend was observed in the elderly population where plasma klotho concentration decreased as the T alleles in rs650439 increased. Subjects with a TT genotype had lower plasma klotho concentrations than those with AT+AA genotypes. In conclusion, TT genotype of klotho SNP (rs650439) is correlated with an increased incidence of stroke in hypertensive patients, and the mechanism underlying this correlation might involve the effect of rs650439 T allele on plasma klotho concentrations.

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.

Bitter, Sweet, Salty, Sour and Umami Taste Perception Decreases with Age: Sex-Specific Analysis, Modulation by Genetic Variants and Taste-Preference Associations in 18 to 80 Year-Old Subjects

There is growing interest in relating taste perception to diet and healthy aging. However, there is still limited information on the influence of age, sex and genetics on taste acuity as well as on the relationship between taste perception and taste preferences. We have analysed the influence of age on the intensity rating of the five basic tastes: sweet, salty, bitter, sour and umami (separately and jointly in a “total taste score”) and their modulation by sex and genetics in a relatively healthy population (men and women) aged 18–80 years (n = 1020 Caucasian European participants). Taste perception was determined by challenging subjects with solutions of the five basic tastes using standard prototypical tastants (6-n-propylthiouracil (PROP), NaCl, sucrose, monopotassium glutamate and citric acid) at 5 increasing concentrations (I to V). We also measured taste preferences and determined the polymorphisms of the genes taste 2 receptor member 38 (TAS2R38), taste 1 receptor member 2 (TAS2R38) and sodium channel epithelial 1 beta subunit (SCNN1B), as TAS2R38-rs713598, TAS1R2-rs35874116 and SCNN1B-rs239345 respectively. We found a statistically significant decrease in taste perception (“total taste score”) with increasing age for all the concentrations analysed. This association was stronger for the higher concentrations (p = 0.028; p = 0.012; p = 0.005; p = 4.20 × 10⁻⁵ and p = 1.48 × 10⁻⁷, for I to V in the multivariable-adjusted models). When we analysed taste qualities (using concentration V), the intensity rating of all the 5 tastes was diminished with age (p < 0.05 for all). This inverse association differed depending on the test quality, being higher for bitter (PROP) and sour. Women perceived taste significantly more intense than men (p = 1.4 × 10⁻⁸ for total taste score). However, there were differences depending on the taste, umami being the lowest (p = 0.069). There was a complex association between the ability to perceive a taste and the preference for the same. Significant associations were, nevertheless, found between a higher perception of sour taste and a higher preference for it in women. In contrast, the higher perception of sweet was significantly associated with a higher preference for bitter in both, men and women. The TAS2R38-rs713598 was strongly associated with bitter (PROP) taste (p = 1.38 × 10⁻⁵⁰), having a significant interaction with sex (p = 0.030). The TAS1R2-rs35874116 was not significantly associated with sweet, whereas the SCNN1B-rs239345 was associated (p = 0.040) with salty taste. In conclusion, the inverse association between age and perceived taste intensity as well as the additional influence of sex and some genetic polymorphisms give rise to large inter-individual differences in taste perception and taste preferences that should be taken into account in future studies and for applications in precision nutrition for healthy aging.

Olfactory and gustatory functions after free flap reconstruction and radiotherapy for oral and pharyngeal cancer: a prospective follow-up study

BACKGROUND

The senses of smell and taste can be adversely affected by both tumour- and treatment-related factors amongst head and neck cancer patients. The consequences may negatively impact nutritional status as well as quality of life in this patient population.

PATIENTS AND METHODS

This prospective longitudinal follow-up study is consisted of 44 patients treated for oral cavity, oropharyngeal or hypopharyngeal cancer with tumour resection and microvascular free tissue transfer reconstruction at the Helsinki University Hospital, Helsinki, Finland. Thirty-nine (89%) of them also received radiotherapy. The senses of smell (odour detection, identification and threshold test) and taste (electrogustometry) and quality of life (UW-QOL) were evaluated preoperatively, and at 6 weeks, 3 months, 6 months and 12 months, postoperatively.

RESULTS

There were higher scores in the odour detection values in the 6-week and 3-month tests compared with preoperative values for the tumour side. Other detection scores did not differ statistically from the preoperative values neither in the tumour nor the contralateral side. However, in the odour identification test, all posttreatment values were statistically significantly higher than pretreatment ones. In the olfactory threshold test, no statistically significant differences were found between pre- and posttreatment values. Electrogustometry values for the taste on the tumour side were statistically significantly impaired at 6 weeks (p < 0.05) and at 3 months (p < 0.01) compared with the pretreatment results. They were also impaired at 6 months and at 12 months, although the differences were not statistically significant. The quality of life was impaired after treatment in this patient series. However, the correlation between quality of life and sense of taste was found only at one time point (3 months) and only with contralateral side measurements.

CONCLUSIONS

We conclude that in oral and pharyngeal cancer patients the postoperative taste problems are related to the impairment on the taste sensation in the tongue but not with the sense of smell. Moreover, the impairment in the quality of life is not clearly related to the impaired sense of taste.

Longitudinal study of factors affecting taste sense decline in old-old individuals

The sense of taste plays a pivotal role for personal assessment of the nutritional value, safety and quality of foods. Although it is commonly recognised that taste sensitivity decreases with age, alterations in that sensitivity over time in an old-old population have not been previously reported. Furthermore, no known studies utilised comprehensive variables regarding taste changes and related factors for assessments. Here, we report novel findings from a 3-year longitudinal study model aimed to elucidate taste sensitivity decline and its related factors in old-old individuals. We utilised 621 subjects aged 79-81 years who participated in the Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians Study for baseline assessments performed in 2011 and 2012, and then conducted follow-up assessments 3 years later in 328 of those. Assessment of general health, an oral examination and determination of taste sensitivity were performed for each. We also evaluated cognitive function using Montreal Cognitive Assessment findings, then excluded from analysis those with a score lower than 20 in order to secure the validity and reliability of the subjects' answers. Contributing variables were selected using univariate analysis, then analysed with multivariate logistic regression analysis. We found that males showed significantly greater declines in taste sensitivity for sweet and sour tastes than females. Additionally, subjects with lower cognitive scores showed a significantly greater taste decrease for salty in multivariate analysis. In conclusion, our longitudinal study revealed that gender and cognitive status are major factors affecting taste sensitivity in geriatric individuals.