Doc: Healthy diet, avoiding oxalate
Dear Dr. Roach: I have had several kidney stones and was advised to avoid oxalate. I was told that green, leafy vegetables and grains are high in oxalate. How can my diet be healthy if I avoid these healthy foods?
Dear D.F.: Calcium oxalate is the most common type of kidney stone, so limiting dietary oxalate makes sense. However, increasing water intake, dietary calcium and potassium can help prevent kidney stones. It is paradoxical, but dietary calcium reduces kidney stone risk while calcium supplements increase kidney stone risk. Also, vitamin C increases kidney stone risk, so it’s not recommended to take supplemental vitamin C.
There are many places to find the oxalate content of food, starting with your dietician, but websites like lowoxalate.info and ohf.org have nice lists. There you can find many fruits and vegetables that have little or no oxalate, including broccoli, lettuce, cucumber and many others. You do need to avoid spinach, beets and similar vegetables. As far as grains go, corn, rice and wild rice are good choices.
Dear Dr. Roach: My husband was diagnosed with a skin condition called dermatitis herpetiformis 35 years ago. He was prescribed dapsone and has been taking it ever since. We have moved to Florida, and none of the doctors here know anything about dapsone. He is unable to get a prescription.
Right now, he’s miserable with a horrible skin rash with blisters, and he itches constantly. He’s careful with his diet (he’s lactose intolerant), but otherwise can find no answers. Dapsone is the only thing that helps.
Dear M.M.C.: Dermatitis herpetiformis is an uncommon skin disease seen more often in people with ancestry from northern Europe. In the vast majority of cases, it is linked to gluten sensitivity (celiac disease). A gluten-free diet is one mainstay of treatment, and the other is dapsone.
Dapsone is a powerful medicine with many potential side effects that must be used by someone familiar with it who must be monitored carefully. It causes hemolysis (breakdown of blood cells) to a small extent in most people; however, in people with a condition called G-6PD deficiency, the hemolysis can be fatal. If your husband hadn’t been taking it safely before, he would be tested for this common enzyme deficiency before being prescribed dapsone.
Most people with dermatitis herpetiformis who stick to their gluten-free diet carefully are able to stop dapsone eventually.
Your husband needs a very experienced dermatologist and advice on a gluten-free diet. Two places to start are celiac.org and gluten.net. A dietician can be very useful, as well. Fortunately, there are many gluten-free options available now.
Email questions to ToYourGoodHealth@med.cornell.edu.