Effect of Consumption of Cocoa-Derived Products on Uric Acid Crystallization in Urine of Healthy Volunteers

Nutrients. 2018 Oct 16;10(10):1516. doi: 10.3390/nu10101516.


The purpose of this study was to determine the effects of consumption of different cocoa-derived products on uric acid crystallization in urine of 20 healthy volunteers. Participants were requested to select the specific diet that they wished to follow during the 12 h prior to collection of urine. The only restriction was that the diet could not include any product with cocoa, coffee, or caffeine. On the first day, each volunteer followed their selected diet, and an overnight 12 h urine sample was collected as the baseline urine. After seven days on an unrestricted diet, each volunteer repeated the same diet with 20 g of milk chocolate, chocolate powder, or dark chocolate during breakfast and another 20 g during dinner. Overnight 12 h urine samples were then collected. Urine volume, pH, oxalate, creatinine, uric acid, theobromine, and a uric acid crystallization test were determined for each sample. The results for all 20 patients show that uric acid crystallization was significantly lower following the consumption of chocolate powder or dark chocolate relative to baseline or following the consumption of milk chocolate. The results indicated that increased concentrations of urinary theobromine reduced the risk of uric acid crystallization.

Keywords: cocoa; theobromine; therapy; uric acid; urolithiasis.

MeSH terms

  • Adult
  • Aged
  • Caffeine
  • Chocolate*
  • Coffee
  • Creatinine / urine
  • Crystallization
  • Diet / methods
  • Eating / physiology*
  • Female
  • Healthy Volunteers
  • Humans
  • Hydrogen-Ion Concentration
  • Male
  • Middle Aged
  • Oxalates / urine
  • Theobromine / urine
  • Uric Acid / chemistry*
  • Uric Acid / urine
  • Young Adult


  • Coffee
  • Oxalates
  • Uric Acid
  • Caffeine
  • Creatinine
  • Theobromine