| The normal
diet consists of fat, carbohydrate and proteins.
In structure, both fat and carbohydrate are very
similar, in that they contain only carbon,
hydrogen and oxygen; whereas the proteins differ
by the extra content of nitrogen. When digested
fats and carbohydrates are metabolised they
breakdown into carbon dioxide and water, both of
which are volatile and can be excreted by the
lungs. Water is also excreted by the kidneys in
urine and by the skin as sweat. The protein,
however, metabolises to form non-volatile
material called the 'nitrogenous waste', a
mixture of many compounds of which urea and
creatinine are most important and well known. One
of the main functions of the kidney is to remove
these poisons, urea and creatinine, from the body
through the urine. It naturally follows that the
greater the protein intake of a human being, the
larger will be the nitrogenous waste load
produced and greater the work demand on the
kidneys to excrete it in the urine.
Non-vegetarian diets have much larger protein
content than the vegetarian diets. Eating a
non-vegetarian diet produces a larger work demand
on both kidneys. This has been clearly
demonstrated by scientific methods. Until recently it
was thought that in health, the kidneys are able
to meet this extra demand quite well and perform
satisfactorily, but recent animal experiments
have revealed quite clearly that when healthy
kidneys are constantly exposed to very large
protein loads, they seem to age much faster and
may be tne cause of the development of high blood
pressure in animals. With the appearance of this
scientific data the whole world is now sitting up
to realise that too much protein is deleterious
to healthy kidneys. In fact the average adult
western non-vegetarian diet consists of I - 1.5
gms/kg body weight of protein whereas the minimum
requirement for good health is only 0.75 gms/kg
body weight which is the requirement quite
adequately met by the average Indian adult
vegetarian diet.
In Renal
Failure, where the kidney's efficiency slowly and
subtly reduces from 100% to 30% without even
giving a slight warning to the patient, it is
quite obvious that a greater work demand on the
kidneys put by a non-vegetarian diet would
further produce a great strain on the already
diseased kidney. This has been very exhaustively
proved in patients of renal disease such as
glomerulonephritis, chronic renal failure, renal
disease due to diabetes (diabetic nephropathy)
and renal disease due to high blood pressure
(hypertensive nephrosclerosis). In these
diseases, the patient suffers an initial mild and
prolonged phase of "azotaemia" wherein
life is possible without dialysis before reaching
the stage of "uraemia" at which stage
life can only be maintained by doing dialysis.
The phase of "azotaemia" is best
treated by a very strict dietary protein
restriction and this is best achieved by a
vegetarian diet containing 30 gms proteins of
which 20 gms are supplied by milk and milk
products while the remaining 10 gms comes from
vegetable, cereals etc. 'Azotaemia" is best
tolerated this way and the "uraemia"
phasc may be postponed by years by this dietary
principle in conjunction with other dietary
restrictions of salt, water, potassium and the
usage of certain drugs.
Gout is a
disease affecting joints and causing kidney
stones. It is due to deposition, in joints and
kidneys, of uric acid which is both generated in
the body and also derived from food products like
all meats. Those suffering from gout and uric
acid kidney stones benefit most by omitting meat
from their diet and converting to a vegetarian
diet. With proper adjuvant therapy the incidence
of kidney stones reduces and the patient suffers
less joint pains.
In
Conclusion The Nephrologist, like the
diabetologist uses diet as a major part of his
therapeutic armamentarium most effectively and
must prescribe the total diet of his patient
taking into consideration the calories, fluid
intake vis-a-vis urine output, protein,
carbohydrate and fat intake, potassium and salt
intake. Each patient will be given a different
diet prescription but the one universal advice
that will apply to all will be "It is better
for you to become a vegetarian ".
Nephrologists have come to believe that this
advice is applicable even to those who have no
renal disease so as to prevent normal kidneys
from overworking and aging rapidly. In fact, many
nephrologists in western countries have become
vegetarians due to this belief !
SUGGESTED
FURTHER READING
- Barry
M. Brenner and Jay H. Stein. "The
Progresslve Nature of Renal Disease"
Churchill Livingstone Ed. Williarn E.
Mitch, 1986
- Brenner
B.M., Meyer T.W. and Host setter T.H.
Dietary Proteins Intake and the
Progressive Nature of Kidney Disease. New
Eng Journal Medicine 1982, 307, 652.
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