How diet helps kidney patientsremove waste

Researchers claimed recently that a grain-
based vegetarian diet could help chronic
kidney disease patients avoid accumulating
toxic levels of phosphorous in their bodies.
Dr Sharon Moe, of the Indiana University
School of Medicine and Roudebush
Veterans ’ Affairs Medical Centre in
Indianapolis and colleagues, write about
their findings in a study due to be
published this week in the Clinical Journal of
the American Society of Nephrology.
If the body cannot get rid of phosphorous,
it builds up and causes heart disease and
eventually death.
Healthy kidneys filter toxic minerals like
phosphorous so they do not build up toxic
levels in the bloodstream.
This blood cleaning process does not work
so well in people with chronic kidney
disease (CKD) who have to find other ways
to compensate.
One way is to follow medical guidelines that
recommend low phosphorous diets for
people with CKD, but since food labels do
not list phosphorous content, that is easier
said than done, so Moe and colleagues
decided to compare a vegetarian diet
against a meat diet to see how they
affected phosphorous levels in patients
with CKD.
They recruited nine volunteers with CKD and
got them to follow a vegetarian or meat-
based diet for a week, and then two to four
weeks later got them to follow the opposite
diet. The volunteers gave blood and urine
samples at the end of each week on both
diets.
Moe and colleagues found that despite the
two diets offering equivalent protein and
phosphorous concentrations, when they
were on the vegetarian diet, the patients
had significantly lower levels of
phosphorous in their blood and urine
samples, than when they were on the meat-
based diet.
“Although the study was not designed to
examine the reason for this difference, we
already know that a grain-based diet has a
lower ratio of phosphate to proteins and
much of it comes from phytate, which is not
absorbed in the human body, ” the
researchers said.
Moe and colleagues concluded that these
findings show that where protein comes
from in a diet has a significant effect on
phosphorous levels in CKD patients.
If these findings are confirmed by larger
studies, then it provides a good reason for
recommending that patients with CKD follow
a diet where most of the protein comes
from grain-based vegetarian sources of
protein, they added.
Such a diet “would allow increased protein
intake without adversely affecting
phosphorus levels, ” they wrote.
They also recommended that when patients
with CKD receive counseling about food and
diets, they should be told about
phosphorous and its effects and the
sources of protein from which it derives.