title: The effect of dietary protein on the efficacy of L-dopa: a double-blind study.
abstract: We randomly placed 10 parkinsonian patients on high- and low-protein diets that tasted and looked alike, each for 1 week. All patients were taking L-dopa and carbidopa with or without other antiparkinson medications; medications remained unchanged. A "blind" physician recorded the modified Columbia scores, objective measurements of rigidity, movement velocity, and pegboard tests three times a day for 5 days during each week. The patients recorded fluctuations hour to hour. We measured serial blood L-dopa levels on day 4 of each week. Performance was significantly better while the patients were on low-protein diets. These results did not correlate with blood L-dopa levels, which had higher peaks in three patients while they were on high-protein diets despite inferior performance and increased number of "off" hours. Thus, high dietary protein probably affects the efficacy of L-dopa at a central level.
authors.affiliation: Department of Medicine, University Hospital, University of British Columbia, Vancouver, Canada.
authors.forename: J K
authors.initials: JK
authors.lastname: Tsui
authors.forename: S
authors.initials: S
authors.lastname: Ross
authors.forename: K
authors.initials: K
authors.lastname: Poulin
authors.forename: J
authors.initials: J
authors.lastname: Douglas
authors.forename: D
authors.initials: D
authors.lastname: Postnikoff
authors.forename: S
authors.initials: S
authors.lastname: Calne
authors.forename: W
authors.initials: W
authors.lastname: Woodward
authors.forename: D B
authors.initials: DB
authors.lastname: Calne
mesh_terms: D000978:Antiparkinson Agents / Q000627:therapeutic use*; D001971:Bromocriptine / Q000627:therapeutic use; D002230:Carbidopa / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D004044:Dietary Proteins; D004311:Double-Blind Method; D004338:Drug Combinations / Q000627:therapeutic use; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000178:diet therapy / Q000188:drug therapy / Q000503:physiopathology*; D011897:Random Allocation; D012642:Selegiline / Q000627:therapeutic use
chemical_list: D000978:Antiparkinson Agents; D004044:Dietary Proteins; D004338:Drug Combinations; C009265:carbidopa, levodopa drug combination; D012642:Selegiline; D001971:Bromocriptine; D007980:Levodopa; D002230:Carbidopa