Why the DASH and Mediterranean diets do not work for patients on dialysis

By: Peggy Harum, R.D., L.D.
December 03, 2018

Patients on hemodialysis experience a high mortality risk of 10% to 20%. This is at least 10-times higher than in the general population. There have been decades of research, but no high-quality evidence that specific treatments or preventative strategies can reduce mortality in this setting. 1-4

There are multitudes of weight loss diets and programs emerging all the time. On Jan. 3, 2018, the dietary approaches to stop hypertension, or DASH diet, was ranked the best diet for the eighth year in a row by U.S. News & World Report. It looks easy to follow. It is designed to lower blood pressure, promotes weight loss, lowers cholesterol and helps manage and/or prevent diabetes. However, is it a good diet for patients on dialysis?

NKF endorsement

Interestingly, the National Kidney Foundation tells us that the DASH diet is a recognized treatment for hypertension, heart disease and kidney disease. It can slow the progression of both heart disease and kidney disease. However, the NKF warns the DASH diet should not be used by people on dialysis because individuals on dialysis have special dietary needs that should be discussed with a registered dietitian (preferably a renal dietitian). 5

There are lifestyle modifications, like healthy diets and exercise, that have beneficial effects on cardiovascular risk factors. Hypertension, insulin resistance and dyslipidemia could be improved in the general population with these changes. Recommended diets, including the Mediterranean and DASH diets, which emphasize the intake of fruits, vegetables, fish and low-fat dairy items, along with reduced intake of meat, refined sugars, salt and saturated fat, are associated with a 10% to 30% lower risk of cardiovascular disease and mortality in the general population.

A recent article in the Journal of the American Society of Nephrology discussed the association of Mediterranean and DASH diets with mortality in adults on hemodialysis.6 This study looked at 9,757 adult patients on hemodialysis. Cardiovascular disease accounted for about 40% of the deaths. In this study, the follow-up involved 8,110 patients on hemodialysis with 2,087 deaths (829 cardiovascular related) followed for a median period of almost 3 years. The Mediterranean and DASH diet scores were generally low and consistent across a range of European countries. There was no evidence that higher Mediterranean or DASH diet scores were associated with lower risk of cardiovascular or all-cause mortality. This study concluded that the Mediterranean and the DASH diets did not associate with cardiovascular or total mortality in hemodialysis. Dietary patterns that are protective in the general population do not predict better clinical outcomes in patients on hemodialysis.