Radiation-induced changes in taste acuity in cancer patients

Abstract

Changes in taste acuity were measured in 27 patients with various forms of cancer who received radiation to the head and neck region. In 9 of these patients (group I) measurements of taste acuity were made more than 1 year after completion of radiation therapy. In the other 18 patients (group II) taste measurements were made before, during and approximately I month after radiation therapy. Taste acuity was measured for four taste qualities (salt, sweet, sour and bitter) by a forced choice-three stimulus drop technique which measured detection and recognition thresholds and by a forced scaling technique which measured taste intensity responsiveness. In group II patients impaired acuity, as indicated by elevated detection and recognition thresholds, was observed approximately 3 weeks after initiation of radiotherapy. The bitter and salt qualities showed the earliest and greatest impairment and the sweet quality the least. Taste intensity responsiveness also was impaired in group II patients. As for thresholds, scaling impairment was most severe for bitter and salt taste qualities. Scaling impairment occurred before changes in either detection or recognition thresholds. Detection and recognition thresholds determined in group I patients also showed salt and bitter qualities were affected more severely than either sweet or sour qualities. Zinc administration to group I patients in an uncontrolled study suggested that zinc therapy may be useful in ameliorating taste impairment in some patients. These results suggest that taste loss may be a factor in the anorexia and weight loss that is observed commonly in patients who have undergone radiation treatment. Correction of this abnormality may be useful in aiding the nutritional status of these patients.