title: DASH-style diet and 24-hour urine composition.
abstract: OBJECTIVE
  We previously observed associations between a Dietary Approaches to Stop Hypertension (DASH)-style diet and large reductions in kidney stone risk. This study examined associations between a DASH-style diet and 24-hour excretions of urinary lithogenic factors.
  
  
  METHODS
  We studied 3426 participants with and without nephrolithiasis in the Health Professionals Follow-up Study (HPFS) and the Nurses' Health Studies (NHS) I and II. A dietary DASH score was based on seven components: high intake of fruits, vegetables, nuts and legumes, dairy products, and whole grains and low intake of sweetened beverages and red and processed meats. We used analysis of covariance to adjust for age, stone history, body size, and other factors.
  
  
  RESULTS
  Comparing participants in the highest to lowest quintiles of DASH score, multivariate-adjusted urinary calcium excretion was 3% greater in HPFS (P trend 0.12), 10% greater in NHS I (P trend <0.01), and 12% greater in NHS II (P trend 0.05). Urinary oxalate was 4% to 18% greater (P trend all ≤0.03), urinary citrate was 11% to 16% greater (P trend all <0.01), and urinary volume was 16% to 32% greater (P trend all <0.001). Higher DASH score was associated with higher urine potassium, magnesium, phosphate, and pH, and lower relative supersaturations (RSS) of calcium oxalate (women only) and uric acid.
  
  
  CONCLUSIONS
  A DASH-style diet may reduce stone risk by increasing urinary citrate and volume. The small associations between higher DASH score and lower RSS suggest unidentified stone inhibitors in dairy products and/or plants.
authors.affiliation: Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA. entaylor@partners.org
authors.forename: Eric N
authors.initials: EN
authors.lastname: Taylor
authors.forename: Meir J
authors.initials: MJ
authors.lastname: Stampfer
authors.forename: David B
authors.initials: DB
authors.lastname: Mount
authors.forename: Gary C
authors.initials: GC
authors.lastname: Curhan
mesh_terms: D000328:Adult; D000368:Aged; D002118:Calcium / Q000652:urine; D019343:Citric Acid / Q000652:urine; D005260:Female; D005638:Fruit; D006801:Humans; D006973:Hypertension / Q000178:diet therapy* / Q000652:urine*; D007669:Kidney Calculi / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D019815:Oxalic Acid / Q000652:urine; D011188:Potassium / Q000652:urine; D013431:Sulfates / Q000652:urine; D014675:Vegetables
chemical_list: D013431:Sulfates; D019343:Citric Acid; D019815:Oxalic Acid; D011188:Potassium; D002118:Calcium