title: Effect of soda consumption on urinary stone risk parameters.
abstract: OBJECTIVE
  Fluid consumption has been demonstrated to influence kidney stone formation. Studies have shown that consumption of cola may be a risk factor for stone disease, while fluids containing citric acid may attenuate stone activity. Diet was not always controlled in these investigations, however. We undertook a study to determine the impact of three different fluids on urinary stone risk factors.
  
  
  METHODS
  Six healthy nonstone-forming adults were placed on a standardized metabolic diet and consumed three different types of fluid during three 5-day periods. There was a 2-day washout between each sequence. The three fluids administered during these periods were Le Bleu water, caffeine-free Diet Coke, and Fresca (citrate containing). These two soda preparations were chosen to prevent the known increase in calcium excretion promoted by carbohydrates and caffeine. Twenty-four hour urine specimens were collected on days 4 and 5 of each sequence. The following urinary parameters were measured: Volume, calcium, oxalate, creatinine, uric acid, citrate, sodium, magnesium, phosphorus, sulfate, urea nitrogen, pH, and supersaturation indices. A paired t test was used for statistical analysis.
  
  
  RESULTS
  Urinary volumes were significantly higher and supersaturation of calcium oxalate significantly lower compared with a self-selected dietary regimen. A decrease in uric acid was also seen in the Fresca cohort. There were no statistically significant differences for any of the urinary parameters.
  
  
  CONCLUSIONS
  There is no increased risk or benefit to consuming Fresca or caffeine-free Diet Coke compared with Le Bleu bottled water with respect to stone formation.
authors.affiliation: Division of Urology, Department of Surgery, Wake Forest University Baptist Medical Center, Winston Salem, North Carolina 27157, USA. cpassman@wfubmc.edu
authors.forename: Corey M
authors.initials: CM
authors.lastname: Passman
authors.forename: Ross P
authors.initials: RP
authors.lastname: Holmes
authors.forename: John
authors.initials: J
authors.lastname: Knight
authors.forename: Linda
authors.initials: L
authors.lastname: Easter
authors.forename: Vernon
authors.initials: V
authors.lastname: Pais
authors.forename: Dean G
authors.initials: DG
authors.lastname: Assimos
mesh_terms: D000328:Adult; D001628:Beverages; D004327:Drinking Behavior; D005260:Female; D006801:Humans; D008297:Male; D012307:Risk Factors; D016482:Urinalysis; D014545:Urinary Calculi / Q000473:pathology* / Q000652:urine