Abu Dhabi, United Arab Emirates (UroToday.com) One of the cornerstone presentations in the “Controversies in Medical Management of Stones” plenary presentation at the World Congress of Endourology explained the role of urinary oxalate in diets and how it may contribute to stone formation. Dr. Kyle Wood, a urologist from the University of Alabama at Birmingham, presented an interesting breakdown of which foods in people’s everyday diet contain high oxalate levels and whether eliminating those foods would be beneficial in reducing the formation of stones.   Dr. Wood explained that there are three main sources of urinary oxalate: diet, endogenous synthesis, and ascorbate.

The main premise of Dr. Wood’s presentation was that he believes that clinicians should counsel patients with calcium oxalate stones and relatively high urinary oxalate to limit intake of oxalate-rich foods and maintain normal calcium consumption. He further went on to state that prior research studies have demonstrated that, among calcium oxalate stone-formers, urinary calcium is equally effective as urinary oxalate in increasing the relative saturation ratio (RSR) of calcium oxalate.

He further argues that (1) oxalate has no known health benefits, (2) dietary oxalate increases urinary oxalate, and (3) increasing urinary oxalate is associated with increased kidney stone risk and chronic kidney disease. For these reasons, Dr. Wood is firm in his belief that oxalate should be limited in the foods we consume on a routine basis. A few foods that Dr. Wood mentioned during his presentation that he recommends individuals with high risk of stone formation to avoid are spinach, chard, rhubarb, and star fruit. Conversely, he believes that, although containing high levels of oxalate, foods like potatoes, chocolate, nuts, beets, and bran should be limited but not eliminated from an individual’s diet. Finally, he recommends that meals should contain between 300-400mg of calcium to combat an individual’s tendencies to form stones upon consuming high oxalate foods.

Presented by: Kyle Wood, MD, Department of Urology, The University of Alabama at Birmingham, Birmingham, Alabama 

Written By: Andrew Shea Afyouni, BS, Junior Research Specialist and Medical Student, University of California, Irvine Department of Urology at the 37th World Congress of Endourology (WCE) – October 29th-November 2nd Abu Dhabi, UAE.