Efficacy of Zinc on Concurrent Chemo-radiotherapy Induced Taste Alterations

Taste changes are common in cancer patients receiving concurrent chemoradiation which become a significant complaint and a cause of distress and morbidity. Loss of gustatory function further advances to malnutrition, weight loss, reduced quality of life, poor compliance and even diminished response to drug therapy. Taste is an essential sensation which serves oral intake of food and enables to prevent the ingestion of potentially harmful and poisonous substances. The sense of taste is crucial for an individual's well-being and psychological health. Taste changes may advance to reduced appetite, dietary insufficiency, food repulsion affecting body weight and anorexia further leading to impaired immunity, decline in health status and malnutrition. As taste impairment is not a life-threatening event therefore it might not be reported by some patients. Hence, this aspect is neglected despite being a common and distressing side-effect of chemoradiation. Due to the location of the cancer and the long-term effects of cancer therapies, patients with oral cavity cancers have a specially high prevalence of chemosensory disorders. Zinc is comparatively non-toxic if taken orally, and rather non-toxic in contrast to other trace metals such as manganese and iron. Zinc is an integral element in both the maintenance and repair of taste buds. It is involved in promoting the diffusion of taste stimuli to taste buds. Salivary zinc has been found in association with Gustin (carbonic anhydrase, CA VI), a zinc-metalloprotein enzyme that may be involved with providing nutrition to the human taste buds. Zinc influences the synthesis of gustin required for the growth, development, maintenance and production of taste buds and regulation of taste function. The hypothesis was: Null hypotheses: There is no difference in the taste acuity between test and control group with the administration of zinc sulfate. Alternative hypotheses: There is a difference in the taste acuity between test and control group with the administration of zinc sulfate. Thus, the present study aimed to observe changes in taste function of oral cancer patients by detection and recognition thresholds before beginning their treatment (before chemoradiation and intervention), at the end of chemoradiation and a month after and to evaluate the preventive effect of zinc sulfate on chemoradiation-induced taste changes. To the best of our knowledge, similar study has not been conducted before in our region.