Improvement of uremic hypogeusia by zinc: a double-blind study

Diminished taste acuity may account for the persistence of protein and caloric malnutrition observed in a majority of hemodialysis patients inspite of liberalization of the prescribed amount of dietary protein. Twenty-two patients undergoing thrice weekly hemodialysis for more than 6 months were tested for taste acuity and plasma zinc concentration, after which a double-blind study was instituted using a zinc supplement (50 mg of elemental zinc as zinc acetate per day) or a placebo. The threshold of taste detection and recognition for salt (NaCl), sweet (sucrose), and bitter (urea) but not for sour (HCl) improved significantly in all patients on zinc supplementation. None of these parameters improved in those taking placebo. During the study period, the mean plasma zinc level increased from 75 +/- 8 to 97 +/- 10 microgram/dl (P less than 0.001) in patients receiving zinc acetate. There was not significant change in plasma zinc level in the placebo group (75 +/- 15 to 80 +/- 15). The results of this study show that uremic hypogeusia improved in association with zinc supplementation and elevation of plasma zinc concentration.