A randomized, placebo controlled trial of oral zinc for chemotherapy-related taste and smell disorders

Abstract

Abnormalities in taste and smell are commonly reported in patients receiving chemotherapy and may hinder appetite, dietary intake, nutritional well-being, and quality of life. Oral zinc has been used to treat taste and smell abnormalities in several altered physiologic states, including renal failure, liver disease, head trauma, and pregnancy, with varying results. The authors conducted a double-blinded, placebo-controlled randomized clinic trial over 3 months. Eligible patients were those taking chemotherapy that had alterations in taste and/or smell. The measurement of the primary end point, improvement in altered taste and smell, was made using a 0-100 scale (100 describing no loss or distortion in taste and smell, and 0 describing the worst distortion or loss of taste and smell). Twenty-nine subjects were enrolled in each treatment group, of whom 31 were white, 26 African American, and 1 Native American. Forty-one patients were female. A wide range of cancer types was represented, with breast the most common (21 patients). The zinc dose was 220 mg orally twice daily (equivalent of 50 mg elemental zinc twice daily). There was no statistically significant improvement in loss or distortion of taste or smell with the addition of zinc. There was a trend toward improvement over time in all groups, except in the zinc group where there was a nonsignificant worsening in loss of smell over time. Zinc at standard doses did not provide significant benefit to taste or smell in patients receiving chemotherapy.

FIGURE 1

Loss of taste over time.

FIGURE 2

Loss of smell over time.