A Neural Mechanism of Taste Perception Modulated by Odor Information

Taste changes in paediatric oncology: longitudinal evaluation

OBJECTIVES

Changes in taste is a common symptom in paediatric patients receiving cancer therapies. The primary objective was to describe the prevalence of taste changes longitudinally over a 6-month time frame among paediatric patients with newly diagnosed cancer. Secondary objective was to identify factors associated with taste changes over time.

METHODS

In this longitudinal, single centre study, we included paediatric patients newly diagnosed with cancer within the previous 8 weeks who were 4-18 years of age. Interviews were conducted once monthly for 6 months. We asked participants about their experience with taste changes, whether potential interventions were successful and whether taste changes influenced eating. Risk factors were evaluated using generalised linear mixed-effects models.

RESULTS

Overall, 60 participants were included. At baseline, 23 (38.3%) participants reported experiencing changes in taste, with the proportion significantly declining over time to 13 (21.7%) at 6 months. The most common specific taste changes were food tasting different, bad or bland. The most common helpful strategies were eating liked foods only, brushing teeth or using mouthwash, drinking more liquids and eating food with strong flavour. Taste change was commonly associated with eating less than usual and reduced enjoyment in eating. Nausea, dry mouth and recent vincristine were independent risk factors for taste changes.

CONCLUSIONS

Changes in taste were common within 8 weeks of cancer diagnosis and declined significantly over time. Nausea, dry mouth and recent vincristine were independent risk factors. Future studies should develop and evaluate interventions for managing taste changes in paediatric patients with cancer.

Contribution of ambient noise and hyperbaric atmosphere to olfactory and gustatory function

Introduction

Taste and smell are important for occupational performance and quality of life. Previous studies suggested that the function of these senses might be influenced by ambient pressure and noise. This knowledge would be helpful for divers, submarine crews, or mine workers. The present study aimed to investigate the effects of noise and hyperbaric pressure on olfactory and gustatory functions.

Methods

This prospective controlled study included 16 healthy male divers. Inside a hyperbaric chamber, participants performed olfactory and gustatory function tests at sea level pressure and at 2 bar pressure. The olfaction threshold, and the discrimination and identification of odorants were measured with validated ´Sniffin sticks´. Taste identification and the gustation threshold scores were examined with validated filter paper strips. Tests were performed under two conditions: noise reduction (silence) and white noise stimulation presented at 70 dB sound pressure level.

Results

The results showed that normobaric and hyperbaric ambient pressures did not significantly affect olfactory or gustatory function. Moreover, noise had no relevant impact on taste or odor sensation. The odor identification score was not influenced in hyperbaric conditions, and the odor threshold score was not influenced by ambient noise or both barometric conditions. The only taste modality affected by hyperbaric conditions was the sensitivity to salty taste, but it was not significant.

Conclusion

We concluded that hyperbaric and noisy environments have no influence on gustatory and olfactory function. From a practical point of view, the influence of pressure in moderate hyperbaric occupations should be negligible.

The Impact of Acoustic fMRI-Noise on Olfactory Sensitivity and Perception

Sensory perception is neither static nor simple. The senses influence each other during multisensory stimulation and can be both suppressive and super-additive. As most knowledge of human olfactory perception is derived from functional neuroimaging studies, in particular fMRI, our current understanding of olfactory perception has systematically been investigated in an environment with concurrent loud sounds. To date, the confounding effects of acoustic fMRI-noise during scanning on olfactory perception have not yet been investigated. In this study we investigate how acoustic noise derived from the rapid switching of MR gradient coils, affects olfactory perception. For this, 50 subjects were tested in both a silent setting and an fMRI-noise setting, in a randomised order. We found that fMRI-related acoustic noise had a significant negative effect on the olfactory detection threshold score. No significant effects were identified on olfactory discrimination, identification, identification certainty, hedonic rating, or intensity rating.