Oxalate content of beverages
A high fluid intake is an integral part of the measures for the recurrence prevention of calcium oxalate stone formation. Since dietary oxalate is a primary risk factor for hyperoxaluria, the oxalate content of a wide variety of alcoholic and non-alcoholic beverages was analyzed using a validated HPLC-enzyme-reactor method. The oxalate concentrations were 3.21-6.34. mg/100. mL in green and black teas, 0.28-1.96. mg/100. mL in iced teas and 0.08-1.82. mg/100. mL in herbal teas. The oxalate levels of soft, wellness, energy and sports drinks were below 0.81. mg/100. mL. The oxalate content varied among beer and wine, ranging from 0.30. mg/100. mL in white wine to 1.78. mg/100. mL in non-alcoholic beer. The oxalate concentration of wines was lower than that of the corresponding fruit juices. Certain beverages may provide considerable amounts of highly bioavailable soluble oxalate. Further studies should examine the effect of fermentation on the oxalate content.