Are Low-Phosphorous (Phosphate) Diets Killing Dialysis Patients?

Two years ago, my wife slipped on some ice and broke her leg in two places. One of the breaks was a nasty spiral fracture. She spent Christmas Eve in surgery and Christmas Day in bed. Why did she suffer such a bad break?

After 33 years of type-1 diabetes Nicole ended up with chronic kidney failure. Another two years on dialysis and bone scans showed she had developed advanced osteoporosis.

Osteoporosis is a typical side effect of kidney failure. Phosphates builds up in the bloodstream between dialysis treatments. Phosphates are a byproduct of consuming phosphorus-rich foods. High phosphate levels pull calcium out of the bones, making them weak.

So, as every dialysis patients knows, a low-phosphorous diet is recommended. The theory is that the less phosphorous-rich foods a dialysis patient eats, the better off they are. The problem, of course, is that most protein-rich foods are loaded with phosphorous.

Low-Phosphorous Diet May Result in “Greater Mortality”

A study in the Clinical Journal of the American Society of Nephrology suggests that the typical low-phosphorous diet may be doing more harm than good.

“Our data suggest that prescription of low phosphate [phosphorous] diets did not improve survival among hemodialysis patients and may, in fact, be associated with greater mortality,” said Dr. Brunelli, who led the study.

So why did more hemodialysis patients die on the phosphorous restricted diet? In an article in Science Daily, Dr. Brunelli says this may be because of a “comprised intake of other essential macronutrients — such as protein — that occur unintendedly when low-phosphate diets are prescribed.”

The limited data from this study (not to mention commonsense) suggests that a low-protein diet will do more harm than a high-phosphorous diet. After all, protein provides the “building blocks” for every cell in our bodies. Insufficient protein is deadly.

The Phosphorous-Protein Paradox

Even The Canadian Kidney Foundations acknowledges the phosphorous-protein paradox:

You may need to limit the amount of high and moderate phosphorus foods you eat. These include milk, cheese… and protein foods such as meat, fish and poultry. However, you still need some milk products and protein foods for overall good nutrition…

Just some protein? “Some” can be a very misleading word. “Adequate” might be a better word. Consider that a 150 pound hemodialysis patient requires 14 ounces of protein a day according to The National Kidney Foundation. That’s nearly a pound of meat per day. It’s certainly more than a carton of eggs.

Protein May Be Just As Important For Bone Health

A study on optimizing bone health from The National Institute of Health says: “Isotopic studies have demonstrated greater calcium retention and absorption among individuals consuming higher protein diets, particularly when the calcium content of the diet is limiting.”

Certainly calcium loss is very damaging to bones. That’s obvious. But is a low-phosphorous diet simply replacing a calcium deficiency with a protein deficiency? And is that protein deficiency resulting in even more damage to the bones?

Our Experiments with Phosphorous

So must a dialysis patient choose between death by phosphorous or death by protein deficiency? I hope not.

One partial solution would be to eat a diet containing adequate amounts of protein-rich foods which are lowest in phosphorous. Nicole and I have researched the phosphorous content of protein-rich foods (that are suitable for a low-carb, type-1 diabetic diet). We’ll publish are findings shortly.

We have also been experimenting with ways to:

  • Reduce the loss of calcium from the bones (even if the phosphate levels are too high).
  • Replace the calcium and thus compensate for its loss.
  • Safely bind phosphorous in food.
  • Excrete excess phosphate from the blood.

We’ll publish articles about all these phosphorous experiments in the near future. You can receive an email alert when they are ready.

It’s certainly a complex and important issue. And for reasons I’ll share in a future article, I don’t think phosphorous-binders are a safe or effective method for dealing with the phosphorous paradox.