Failure of oral L-histidine to influence appetite or affect zinc metabolism in man: a double-blind study.
L-Histidine, 4 g/day in gelatin capsules, was administered orally to eight normal volunteers for 2 weeks in a double-blind, balanced, crossover study with 2 weeks of placebo treatment. Body weight, serum and urinary zinc and histidine concentrations, as well as subjective ratings of appetite, taste and smell perception, and food intake were monitored. L-Histidine therapy had no significant effect on appetite, taste and smell perception, food intake, or body weight. Similarly, no effects were observed on total serum zinc, albumin-bound zinc or alpha 2-macroglobulin-bound zinc concentrations, or on urinary histidine excretion. Serum histidine concentrations increased with therapy. Urinary zinc excretion was increased significantly after 1 week, but not after 2 weeks of L-histidine therapy. It can be concluded that oral L-histidine, at the dose used, has no value as an anorectic agent.
D000328:Adult; D000855:Anorexia / Q000188:drug therapy; D001066:Appetite / Q000187:drug effects*; D001798:Blood Proteins / Q000378:metabolism; D001835:Body Weight / Q000187:drug effects; D002986:Clinical Trials as Topic; D004311:Double-Blind Method; D006639:Histidine / Q000097:blood / Q000494:pharmacology* / Q000627:therapeutic use / Q000652:urine; D006801:Humans; D008297:Male; D011485:Protein Binding; D012903:Smell / Q000187:drug effects; D013649:Taste / Q000187:drug effects; D015032:Zinc / Q000097:blood / Q000378:metabolism*
D001798:Blood Proteins; D006639:Histidine; D015032:Zinc