Oxalate content of legumes, nuts, and grain-based flours

About 75% of all kidney stones are composed primarily of calcium oxalate and hyperoxaluria is a primary risk factor for this disorder. Since absorbed dietary oxalate can make a significant contribution to urinary oxalate levels, oxalate from legumes, nuts, and different types of grain-based flours was analyzed using both enzymatic and capillary electrophoresis (CE) methods. Total oxalate varied greatly among the legumes tested, ranging from 4 to 80mg/100g of cooked weight. The range of total oxalate of the nuts tested was 42-469mg/100g. Total oxalate of analyzed flours ranged from 37 to 269mg/100g. The overall data suggested that most legumes, nuts, and flours are rich sources of oxalate. (c) 2004 Elsevier Inc. All rights reserved.