Kidney Diet Tips

Feeling Itchy with Fishy Phosphorus

Recently during dialysis rounds, a patient who diligently follows his diet and takes his medication as prescribed mentioned to me he was having extreme itching. The blood draw showed a high phosphorus level, a possible reason for the itching. When speaking with the patient, he said he developed a rash in addition to the itching.

Detective Work

I suggested he begin a food journal and we would evaluate the foods he was eating. Upon reviewing the food log together, he revealed a new addition to his weekly intake was a variety of frozen fish. This was the only new food in his diet, and the other foods in the log were low in phosphorus. I began doing some research on the brands of fish he was consuming and discovered sodium triphosphate was used to wash the fish. This is a chemical used to wash meats, poultry, shrimp and other seafood before packing. Since it is considered a wash and not as a preservative at this stage of processing, it may not always be listed on food labels.

What is sodium triphosphate?

Sodium triphosphate is an additive used to make fish and shrimp retain water. It is also used in processing of other food and beverages. This additive helps food retain moisture and tenderness, and can be used as an emulsifier or neutralizer in foods. It is also used in laxatives and colonoscopy preparation to clean out the intestine. This chemical can cause gastrointestinal issues such as diarrhea, nausea, vomiting, cramping, and gas. Allergic reactions may consist of hives, rash, itching and breathing difficulties.

Fortunately, for my patient, his phosphorus blood test result returned to normal after he eliminated the fish in question. To his relief the extreme itching also resolved.

Learning as much as possible about how the foods we eat are processed is important. When avoiding dietary phosphates, reading labels is essential. If a high phosphorus blood level or an allergy occurs after trying a new food or brand, then consider reaching out to the food manufacturer to inquire about phosphates used as a wash. Your dietitian can help. When possible, stick to locally sourced foods with the least amount of processing.

Consumer Demand Makes a Difference

As consumers we can use reputable companies that list all chemicals used on food labels. We also have the ability to choose the best quality items we consume. What customers demand today become the items of tomorrow. Put your dollars in products you want to see in the future. Awareness will help you avoid being the victim of itchy fishy phosphorus!

Lynn Taylor MS, RD, LD

Lynn Taylor MS, RD, LD

Lynn is an avid kayaker. In her free time she loves trying new recipes, biking, gardening and traveling.