What is the role of nutritional treatment in kidney disease?

Jürgen Floege, MD, is a professor of medicine, director of the Division of Nephrology and Clinical Immunology at the University Hospital RWTH Aachen, Germany, and Distinguished Fellow of the European Renal Association – European Dialysis and Transplant Association (ERA-EDTA).

Is diet or, more broadly, nutritional treatment important in the course of chronic disease at its various stages?

Diet, nutritional treatment of chronic diseases... Interestingly, we already discussed this when I was a junior doctor, which is, I don’t know, 200 years ago. This question has been around forever and we still have no good answer because nobody really wants to study it. The only big study that tried to resolve this came out inconclusive.

So, in general, what we say is, first of all, nutritional treatment is important because obesity is a severe risk factor for kidney disease—in part mediated by hypertension, by diabetes, but also by direct obesity effects on the kidney. So, no doubt, nutritional treatment is important.

Whether you need to restrict proteins in patients with kidney disease or not is controversial and we no longer really do that. I tell my patient to eat what nature wanted us to do and you can tell that to patients by telling them to look into their mouth. Here we are a horse and we are vegetarians. Here we are a wolf and we are meat eaters. So, obviously nature wanted us to have a half vegetarian diet and if patients consume that, this is certainly a good choice for them.

Nutritional treatment, of course, incorporates many more aspects in kidney disease. Potassium—dialysis patients are the only patients who can commit suicide by eating fruit; phosphate—calcification, which is like the slow death where potassium is the quick death; salt intake—hypertension and fluid retention is huge in patients. So, all my patients see a nutritionist.