‘Taste’ changes: A problem for patients and their dietitians

Investigating oral somatosensory perception and oral symptoms of head and neck cancer patients: insights on eating behaviour

PURPOSE

Sensory alterations and oral manifestations are prevalent among head and neck cancer (HNC) patients. While taste and smell alterations have been thoroughly investigated, studies on their oral somatosensory perception remain limited. Building upon our previous publication that primarily focused on objective somatosensory measurements, the present work examined self-reported sensory perception, including somatosensation and oral symptoms, in HNC patients and evaluated their link with eating behaviour.

METHODS

A cross-sectional study was conducted using self-reported questionnaires on sensory perception, oral symptoms, sensory-related food preference, and eating behaviour among HNC patients (n = 30). Hierarchical clustering analysis was performed to categorise patients based on their sensory perception. Correlations between oral symptoms score, sensory perception, sensory-related food preference, and eating behaviour were explored.

RESULTS

Two distinct sensory profiles of patients were identified: no alteration (n = 14) and alteration (n = 16) group. The alteration group showed decreased preference towards several sensory modalities, especially the somatosensory. Concerning eating behaviour, more patients in the alteration group agreed to negatively connotated statements (e.g. having food aversion and eating smaller portions), demonstrating greater eating difficulties. In addition, several oral symptoms related to salivary dysfunction were reported. These oral symptoms were correlated with sensory perception, sensory-related food preference, and eating behaviour.

CONCLUSION

This study presented evidence demonstrating that sensory alterations in HNC patients are not limited to taste and smell but cover somatosensory perception and are linked to various aspects of eating. Moreover, patients reported experiencing several oral symptoms. Those with sensory alterations and oral symptoms experienced more eating difficulties.

Chemosensory changes during chemotherapy

BACKGROUND

Chemosensory changes that occur during chemotherapy can significantly impact food enjoyment, quality of life and recovery.

AIM

To investigate chemosensory changes reported by oncology patients during chemotherapy.

METHODS

A mixed-method cross-sectional study design was used to explore 100 cancer patients' experiences of chemosensory changes during chemotherapy. All patients completed a questionnaire assessing their taste and smell preferences. A purposive sample of 30 patients underwent a semi-structured interview to elicit their thoughts on their experienced chemosensory changes. Descriptive statistics and themes were examined.

FINDINGS

The mean age of the sample was 50.56 years, and the majority of participants were female. The most stated taste alteration was bitter, while altered food preferences were also commonly experienced. Furthermore, most patients experienced unpleasant odours around food, while some experienced these odours even when food was not present. Overall, five themes were identified: changes in taste, changes in smell, changes in social life, altered comfort and food preferences.

CONCLUSION

Chemosensory changes related to cancer and its treatment impact a person's nutrient intake, food-related behaviours, quality of life and treatment response. Patients who experience chemotherapy-associated chemosensory changes require specialised nutritional therapy to increase their eating-related pleasure. As part of the nutritional assessment, chemosensory alterations should be evaluated regularly.

Taste loss in cancer patients: clinicians' perceptions of educational materials and diagnostic tools

PURPOSE

Cancer therapy is essential and lifesaving; however, it can have short- and long-term consequences on patients' health. Up to 87% of cancer patients report changes in taste function, yet patients report a lack of support from clinicians regarding their experience with taste loss during and following treatment. Thus, the objective of this study was to assess clinicians' knowledge and experience with managing patients with taste loss and identify potential gaps in the availability of educational materials and diagnostic tools.

METHOD

In an online survey, sixty-seven participants who identify as clinicians and practice in the United States and work with cancer patients that complain of taste problems answered questions on their knowledge and experience supporting cancer patients experiencing changes in taste function and provided their opinion on access to educational materials.

RESULTS

The current study reports gaps in participants' knowledge of taste and taste disorder terminology, with 15.4% correctly defining both taste and flavor and roughly half were familiar with specific taste disorder classifications. Over half of the participants reported not having access to adequate information to help their patients manage taste alterations. Only two-thirds of participants reported routinely asking patients if they are experiencing changes in taste function.

CONCLUSION

Clinicians' responses emphasized the need to improve access to educational materials regarding taste changes and increase the availability of information regarding management strategies. Addressing these inequities in education and improving the standard of care is the first step in improving the care for cancer patients suffering from altered taste function.

Taste changes during radiotherapy for head and neck cancer

INTRODUCTION

Taste changes (dysgeusia) during radiotherapy for head and neck cancer are associated with malnutrition, tube feeding and reduced toleration of treatment.

METHOD

The MD Anderson symptom inventory - head and neck (MDASI-HN) questionnaire was completed by patients in a single department receiving radical radiotherapy or chemo-radiotherapy for head and neck cancer during weeks 1 and 4 of radiotherapy. Participants who developed dysgeusia in week 4 completed supplementary questions exploring what foods they could taste and how they managed taste changes.

RESULTS

At week 4, 97% of 61 participants reported taste changes, 77% reporting moderate or severe changes. 30% of participants reported taste changes during week 1. Patients with oropharyngeal, oral cavity and parotid gland tumours were most likely to develop dysgeusia. Females were more likely than males to report taste changes. A soft, semi-liquid diet was reportedly easier to tolerate as the more food was chewed the worse the taste became.

CONCLUSIONS

Patients having radiotherapy for all head and neck cancers should be warned of the very high risk of developing taste changes and the time scale for this. Patients with taste changes should be advised a softer diet requiring less chewing will be better tolerated. The finding that females are more at risk than males of dysgeusia needs further investigation.

IMPLICATIONS FOR PRACTICE

Patients with head and neck cancer should expect taste changes from the start of radiotherapy. Patients with dysgeusia should be advised that soft, semi-liquid foods that require less chewing before swallowing are easier to tolerate and that taste changes day-to-day.

Oral Somatosensory Alterations in Head and Neck Cancer Patients-An Overview of the Evidence and Causes

Food-related sensory alterations are prevalent among cancer patients and negatively impact their relationship with food, quality of life, and overall health outcome. In addition to taste and smell, food perception is also influenced by somatosensation comprising tactile, thermal, and chemesthetic sensations; yet studies on oral somatosensory perception of cancer patients are lacking to provide patients with tailored nutritional solutions. The present review aimed to summarise findings on the oral somatosensory perception of head and neck cancer (HNC) patients and the potential aetiologies of somatosensory alterations among this population. Subjective assessments demonstrated alterations in oral somatosensory perception such as sensitivity to certain textures, spices, and temperatures. Physiological changes in oral somatosensation have been observed through objective assessments of sensory function, showing reduced localised tactile function and thermal sensitivity. Changes in whole-mouth tactile sensation assessed using texture discrimination and stereognosis ability seem to be less evident. Available evidence indicated oral somatosensory alterations among HNC patients, which may affect their eating behaviour, but more studies with larger sample sizes and standardised assessment methods are needed. Unlike other types of cancers, sensory alterations in HNC patients are not only caused by the treatments, but also by the cancer itself, although the exact mechanism is not fully understood. Prevalent oral complications, such as xerostomia, dysphagia, mucositis, and chemosensory alterations, further modify their oral condition and food perception. Oral somatosensory perception of cancer patients is an under-investigated topic, which constitutes an important avenue for future research due to its potential significance on eating behaviour and quality of life.

Taste alterations and oral discomfort in patients receiving chemotherapy

PURPOSE

Taste alterations (TA) and oral discomfort in cancer patients are neglected side effects of the disease and treatments. They contribute to poor appetite, decrease food intake and affect quality of life, leading to adverse outcomes such as malnutrition and depression. The study aimed to explore TAs in relation to other oral conditions causing discomfort in cancer patients. Additionally, the correlation between patients' acidity of saliva and experienced TAs and oral discomfort was evaluated.

METHODS

A case study including 100 patients diagnosed with cancer receiving chemotherapy or immunotherapy. Data were collected using two questionnaire forms: the Chemotherapy-induced Taste Alteration Scale (CiTAS) and an additional information questionnaire. Saliva samples were collected for each patient and measured with a pocket pH meter. Data were analysed using descriptive statistics, and comparisons were performed using the Kruskal-Wallis H test, Mann-Whitney U test and Fisher's exact test.

RESULTS

The prevalence of reported TAs was 93%. Patient age, oral discomfort and swallowing difficulty were found to be significant factors for experienced TAs (p < 0.05). No correlation between patients' acidity of saliva and reported TAs and oral discomfort was found.

CONCLUSION

CiTAS proved to be a convenient tool to collect information about TAs in cancer patients. Using the CiTAS tool, a high prevalence (93%) of reported TAs in cancer patients receiving chemo- or immunotherapy was found. CiTAS provides a fast and cheap recognition of symptoms and causes of TAs that can be addressed.

Flavor alterations in cancer treatment: Extrinsic factors as a means of augmentation

Flavor, comprising taste, smell and somatosensory inputs, is commonly altered in patients undergoing chemotherapy resulting in malnutrition leading to cachexia. A narrative review considered taste and smell alterations associated with malignancies treated using chemotherapy and the various interventions proffered to lessen alterations. Many of the currently used interventions directed towards enhancing intrinsic factors of food appeared ineffective in encouraging intake of adequate nutrition to ward off complications of malnutrition. Counselling is used in some cases with positive results. The use of extrinsic influences commensurate with the principles of food behavior and gastronomy are considered as a means of providing purpose to patients to accommodate flavor loss which when integrated with counseling and appropriate intrinsic factors are potentially a means of curtailing malnutrition and enhancing the psychological status of the patient. The close association between the cephalic phase responses (CPRs) and the control of eating and digestive behaviors is multifaceted, and when the influences of taste and smell are diminished, other contributing factors guiding CPRs may compensate a deficit. The need for the application of a consistent lexicon is essential when describing taste and smell alterations.

Taste Function in Adults Undergoing Cancer Radiotherapy or Chemotherapy, and Implications for Nutrition Management: A Systematic Review

BACKGROUND

Taste changes are commonly reported by people with cancer undergoing radio- or chemotherapy. Taste changes may compromise dietary intake and nutritional status.

OBJECTIVE

To understand whether or not taste change is associated with cancer diagnosis or treatment modality in adults.

METHODS

A systematic literature search up to December 31, 2019, was conducted using PubMed, Embase, and PsycInfo (International Prospective Register of Systematic Reviews protocol no. CRD42019134005). Studies in adults with cancer objectively assessing the effect of a cancer diagnosis or chemotherapy and/or radiotherapy treatment on taste function compared with healthy controls or within participant changes were included. Additional outcomes were food liking, appetite, dietary intake, nutritional status, and body composition. Reference lists of relevant articles were searched to identify additional articles. Quality was assessed using the Academy of Nutrition and Dietetics quality criteria checklist.

RESULTS

A total of 24 articles were included, one of which consisted of two studies that reported the effects of radiotherapy and chemotherapy separately. From the total 25 studies reported in 24 published articles, 14 studies examined effects of radiotherapy, and remaining 11 studies examined chemotherapy. There is limited evidence of a cancer diagnosis per se contributing to taste dysfunction. Impaired taste function was reported in almost all radiotherapy studies, occurring as early as Week 3 of treatment and lasting for 3 to 24 months posttreatment. During chemotherapy, impairment of taste function was less consistently reported, occurring as early as the first few days of chemotherapy, and persisting up to 6 months posttreatment. Taxane-based chemotherapy was reported to affect taste function more than other treatments. Several studies reported reduced liking for food, appetite, and dietary intake. Only one study reported nutritional status of participants, finding no association between taste function and nutritional status. No studies examined associations between taste changes and body composition.

CONCLUSIONS

This review highlights the importance of considering treatment modality in practice. Research is required to identify factors contributing to taste alteration and to inform evidence-based interventions.

Characterizing Dysgeusia in Hemodialysis Patients

Dysgeusia (abnormal taste) is common in those with chronic kidney disease and contributes to poor nutritional intake. Previous sensory work has shown that taste improves after dialysis sessions. The goal of this pilot study was to characterize altered taste perceptions in patients on dialysis compared with healthy adults, and to evaluate relationships between serum parameters with taste perceptions. We hypothesized that patients undergoing dialysis would experience blunted taste intensities compared with controls, and that serum levels of potential tastants would be inversely related to taste perception of compounds. Using a cross-sectional design, we carried out suprathreshold sensory assessments (flavor intensity and liking) of tastants/flavors potentially influenced by kidney disease and/or the dialysis procedure. These included sodium chloride, potassium chloride, calcium chloride, sodium phosphate, phosphoric acid, urea, ferrous sulfate, and monosodium glutamate. Individuals on maintenance hemodialysis (n= 17, 10 males, range 23-87 years) were compared with controls with normal gustatory function (n=29, 13 males, range 21-61 years). Unadjusted values for intensity and liking for the solutions showed minimal differences. However, when values were adjusted for participants' perceptions of water (as a control for taste abnormalities), intensity of monosodium glutamate, sodium chloride, and sodium phosphate solutions were more intense for patients on dialysis compared with controls. Some significant correlations were also observed between serum parameters, particularly potassium, for dialysis patients and sensory ratings. These results suggest altered taste perception in patients during dialysis warrants further study.

Chemosensory Changes from Cancer Treatment and Their Effects on Patients' Food Behavior: A Scoping Review

Individuals undergoing treatment for cancer can experience changes in taste or smell that are often assumed to affect constructs related to food behavior, although this relationship is rarely measured directly. To ascertain the extent to which measured changes in taste and smell during and after cancer treatment affect food behavior, we conducted a scoping review and completed a comparative analysis for studies that met our criteria, which were: they directly measured cancer patients’ (a) psychophysical response to taste and/or olfactory stimuli, and (b) food behavior (including food enjoyment, food preference, dietary intake) in people affected by cancer. Eleven studies met these criteria and were included in the review. All 11 studies evaluated taste and five also measured smell. A comparative analysis exploring taste and food behavior shows that a reduced sweet taste function (decreased sensitivity) was associated with a reduced intake of a variety of different macro and micro nutrients, reduced appetite, and overall lower energy intake. One out of six studies that measured smell and food measured observed changes in olfactory function following cancer treatment. There were no significant relationships reported between olfactory measures and food behavior. Taste changes that arise from cancer treatment appear to have a direct effect on food behavior, although there is a need for more research using standardized measures and larger sample sizes. A better understanding of taste alterations and their implications for dietary intake and food enjoyment will support optimal nutritional health by identifying strategies to help patients eat well during and after cancer treatment.

Taste genetics and gastrointestinal symptoms experienced in chronic kidney disease

BACKGROUND/OBJECTIVES

It is unknown what causes uraemic symptoms in renal disease. Chronic kidney disease (CKD) patients are known to have increased levels of urea, sodium, potassium and phosphate in their saliva compared with those without renal disease. The present cross-sectional study investigated associations between known genetic traits of taste and self-reported upper gastrointestinal (GI) symptoms experienced in CKD patients with the changes in saliva composition found in renal failure.

SUBJECTS/METHODS

Fifty-six CKD patients (35 males, 21 females, age 67±14 years), with stages 4 and 5 renal failure, selected from a tertiary hospital renal outpatient clinic participated in this study. Subjects answered a questionnaire to assess upper GI symptoms and tested for the genetic taste recognition thresholds of thiourea, phenylthiocarbamide and sodium benzoate. Saliva samples were collected to determine biochemical composition. Possible associations between genetic taste variations, saliva composition and upper GI symptoms were investigated.

RESULTS

Of the 56 patients enroled, 29 (52%) reported major upper GI uraemic symptoms, whereas 27 (48%) had no symptoms or only minor complaints of dry mouth. There was a strong association between the symptomatic burden a patient experienced and the genetic ability to taste thiourea (P<0.0003). Uraemic symptoms of taste changes (P<0.004) and nausea (P<0.002) were found to be related to a patient's genetic ability to taste thiourea.

CONCLUSIONS

This study provides evidence that the genetic ability to taste thiourea as bitter, in combination with the increase in active compounds found in CKD patient's saliva, impacts on the uraemic upper GI symptoms experienced.