with moderate-to-severe chronic renal failure, reduced
protein intake has also been shown to decrease the risk
of end-stage renal disease, based on a systematic
review of eight randomized trials with 1,524 patients
who were followed for at least one year. Renal death
was defined as initiation of dialysis, kidney transplant,
or patient death. The incidence of renal death was
13.5% in patients following the low-protein diet com-
pared with 19.4% in patients receiving the higher-
protein diet. However, there was insufficient evidence
to determine the optimal level of protein intake.
However, it is known that although the low-
protein diet may help those with chronic kidney or
liver disease, the diet is also known to lead to muscle
loss. In 2004 researchers in the Nutrition, Exercise
Physiology, and Sarcopenia Laboratory of the Jean
Mayer USDA Human Nutrition Research Center on
Aging at Tufts University (HNRCA) in Boston, Mas-
sachusetts, reported on a study involving a group of
volunteers with chronic kidney disease who consumed
a low protein diet. About half the group engaged in
resistance training, while the other half served as a
control group. Among the strength-trained partici-
pants who exercised for 45 minutes (including warm-
up and cool-down) three times per week for 12 weeks,
measurements showed that, on average, total muscle
fiberincreased by 32 percent, and muscle strength
increased by 30 percent. Those who did not exercise
lost on average about 3% of their body weight, or
about 9 pounds.
Researchers studying a group of vegetarians who
had maintained a diet relatively low in protein and
calories found that they had lower blood levels of
several hormones and other substances that have
been tied to certain cancers. Additionally it has been
shown that a low protein diet protects against gout,
which is caused by too much uric acid in the blood.
The excess uric acid forms crystal deposits in joints,
particularly in the big toe, feet and ankles, resulting in
episodes of pain.
A low protein diet has also been shown to help
persons with Parkinson’s disease. In this disease, dop-
amine-secreting neurons in the brain die-off, leading
to tremors, slowness, and rigidity. The most common
treatment is a dopamine precursor called levodopa.
However, the effects of this drug can decrease over
time, resulting in ‘‘on’’ periods when the person exhib-
its few symptoms and other ‘‘off’’ periods when the
person suffers from high and often debilitating symp-
toms. A research team in Italy showed that lowering
the protein content of the diet can improve levodopa
therapy and reduce the number and length of the ‘‘off
periods.’’ Additional studies are needed to confirm
these results.Resources
BOOKS
Harum, Peggy. Marina Del Ray, CA: R & D Laboratories,
Inc., 1999.
The Cleveland Clinic FoundationCreative Cooking for
Renal Diets.Willoughby, OH: Senay Publishing, Inc.,
2006.
Walser, Mackenzie.Coping with Kidney Disease: A 12-Step
Treatment Program to Help You Avoid Dialysis.
Hoboken, NJ: John Wiley and Sons, Inc., 2004.ORGANIZATIONS
National Kidney Foundation, 30 East 33rd Street New
York, NY 10016. Telephone: 800-622-9010. Website:
kidney.org.
American Liver Foundation, 75 Maiden Lane, Suite 603,
New York, NY 10038. Telephone: 800-465-4837 Email:
[email protected]. Website: www
.liverfoundation.org.Tish Davidson, A.M.Low-sodium diet
Definition
A lowsodiumdiet is a diet that is low in salt,
usually allowing less than 1 teaspoon per day. Many
diseases, including kidney disease, heart disease, and
diabetes, require a patient to follow a low sodium diet.Origins
There is no single origin for the idea behind low
sodium diets. Many hospitals and health centers have
long recommended that people with diseases that are
affected by sodium intake lower the amount of salt in
their diet.Description
The Role of Sodium
The majority of sodium consumed comes from
sodium chloride (NaCl), better known as salt. Salt
has many useful properties, both in food preservation
and for the body. It helps to prevent spoilage by
drawing the moisture out of foods. This helps to
keep bacteria from growing in the food. It can also
kill bacteria that are already growing on the surface of
foods. Before refrigeration technology was developed,Low-sodium diet