title: Effect of blackcurrant-, cranberry- and plum juice consumption on risk factors associated with kidney stone formation.
abstract: OBJECTIVE
  To evaluate the influence of plum-, cranberry- and blackcurrant juice on urinary stone risk factors.
  
  
  METHODS
  Investigations were carried out in 12 healthy male subjects aged 18-38 y. All subjects received a standardized diet formulated according to the dietary recommendations of the German Society of Nutrition. The subjects provided 24 h urine collections in a control, three loading phases. In each loading phase a neutral mineral water was substituted for 330 ml of the particular juice.
  
  
  RESULTS
  Cranberry juice decreased the urinary pH, whereas the excretion of oxalic acid and the relative supersaturation for uric acid were increased. Blackcurrant juice increased the urinary pH and the excretion of citric acid. The excretion of oxalic acid was increased too. All changes were statistically significant. The plum juice had no significant effect on the urinary composition.
  
  
  CONCLUSIONS
  It is concluded that blackcurrant juice could support the treatment and metaphylaxis of uric acid stone disease because of its alkalizing effect. Since cranberry juice acidifies urine it could be useful in the treatment of brushite and struvite stones as well as urinary tract infection.
  
  
  BACKGROUND
  Funded by our own Division respectively the University.
authors.affiliation: Division of Experimental Urology, Department of Urology, University of Bonn, Bonn, Germany. Kessler@Uni-Bonn.de
authors.forename: T
authors.initials: T
authors.lastname: Kessler
authors.forename: B
authors.initials: B
authors.lastname: Jansen
authors.forename: A
authors.initials: A
authors.lastname: Hesse
mesh_terms: D000293:Adolescent; D000328:Adult; D001628:Beverages; D019343:Citric Acid / Q000652:urine; D004032:Diet; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007669:Kidney Calculi / Q000209:etiology* / Q000517:prevention & control / Q000652:urine; D008297:Male; D027861:Prunus; D031965:Ribes; D012307:Risk Factors; D016482:Urinalysis; D029799:Vaccinium macrocarpon
chemical_list: D019343:Citric Acid