Deficit Symptomatology of Schizophrenia Is Associated with Attenuated Taste Identification: Findings from a Cross-Sectional Study.

Schizophrenia is the subject of many studies. There have been reports of taste disturbances in mental disorders. We found a possible relationship between deficit symptoms of schizophrenia and the dysgeusia of monosodium glutamate (MSG). Dysgeusia is a disorder that distorts the sense of taste. People describe all foods as tasting sweet, sour, bitter, or metallic. We aimed to verify whether the level of MSG taste perception may be related to the severity of deficit symptoms. MSG detection threshold was assessed via sublingual administration of three fluid samples containing MSG or water. The MSG samples had different concentrations in each sample. The task was to indicate which of the samples contained MSG, determine the intensity of the taste, and assess the taste as pleasant, unpleasant, or neutral. The study group included 200 patients diagnosed with paranoid schizophrenia according to ICD-10. We found a significant negative correlation between mean intensity of taste and the number of deficit symptoms. The symptoms of taste disturbances reported by the patient should be monitored by clinicians and differentiated between the actual deficits in the field of taste perception and the taste hallucinations as a symptom of psychosis. It is important to continue research in this area.

Effect of Physical Exercise on Taste Perceptions: A Systematic Review.

The effect of physical exercise on nutrition has gained substantial interest in the last decade. Meaningful results have been produced concerning the effect of physical exercise on different appetite hormones and food choice/preference. While it is well known that taste and nutrition are related, the relation between taste and physical activity has not yet been fully explored. This systematic review aims to provide a detailed view of the literature on physical exercise and its effect on taste perceptions. Five tastes were included in this review: sweet, salty, bitter, sour, and umami. Sweet taste intensity, sensitivity, and preference were increased by acute physical exercise, but sweet preference was reduced by chronic physical activity. Perceived intensity and sensitivity decreased overall for salty taste, but an increased preference was noted during/following exercise. Sour taste intensity ratings were decreased following exercise and preference was enhanced. Umami taste intensity and sensitivity increased following exercise and preference was decreased. No significant results were obtained for bitter taste. While evidence regarding the effect of exercise on taste has arisen from this review, the pre-testing nutrition, testing conditions, type of test, and exercise modality must be standardized in order to produce meaningful and reproducible results in the future.