Which Type of Protein is Better for Our Kidneys?

Which Type of Protein is Better for Our Kidneys?


“Which Type of Protein is
Better for Our Kidneys?” Between 1990 and 2010
some of our leading causes of death and disability
haven’t changed. Heart disease was the
leading cause of loss of life and health then and remains
the leading cause today. Some things got better,
like HIV/AIDS, but others got worse, like
chronic kidney disease, a doubling in the tens
of thousands of deaths and the hundreds of thousands
whose kidneys fail completely, requiring kidney transplants or
lifelong dialysis. And about one in eight of us now have chronic kidney
disease whether we know it or not. And most of those with
kidney disease don’t know it. About three-quarters of the millions
affected are unaware their kidneys are starting to fail, which is
particularly worrisome given that early identification
provides an opportunity to slow the progression and alter
the course of disease. So what can we do about it? The Western-style diet is
a major risk factor for impaired kidney function
and chronic kidney disease, also known as the meat-sweet
diet, or standard American diet, causing an impairment of
kidney blood flow, inflammation, and subsequent leakage
of protein in the urine, and a rapid decrease in kidney
function. Table sugar and high-fructose corn syrup is associated
with increased blood pressure and uric acid levels that
can both damage the kidney. And saturated fat, trans
fat, and cholesterol found in animal fat and junk food negatively
impact kidney function as well. The consumption of animal fat can
actually alter the structure of the kidney. And the animal protein can
deliver an acid load to the kidneys, increase ammonia production,
and damage the sensitive kidney cells. That’s why restricting protein intake
is recommended for preventing kidney function decline, though it
may be animal protein in particular, not just protein in general. So the source of the protein, plant
versus animal, may be more important than the amount regarding
adverse health consequences. Animal protein intake
has a profound effect on normal human kidney function,
inducing what’s called hyperfiltration, increasing the workload
of the kidney. This may help explain why
our kidneys fail so often. Unlimited intake of protein-rich foods,
now generally regarded as “normal,” may be responsible for dramatic
differences in kidney function between modern human beings
and their remote predecessors who hunted and scavenged
for meat here and there. Sustained rather than
intermittent excesses of protein requires us to call on our
kidney reserves continuously, causing a kind of unrelenting
stress on our kidneys that can predispose
even healthy people to progressive kidney scarring
and deterioration of kidney function. It’s like always revving
our engine into the red. On the other hand, administration of
an equal quantity of vegetable protein does not appear to have the same
effects. Eating meat, for example, increases the workload on the kidneys
within hours of consumption, but, apparently, taking care of plant
protein appears to be a cinch. This was done with beef, but
any animal protein will do. Eat a meal of tuna fish, and you
can see the increased pressure on the kidneys go up again within
just hours, for both non-diabetics with normal kidneys, and
diabetics with normal kidneys. If instead of having a tuna salad
sandwich you had a tofu salad sandwich with the same amount
of protein, no effect. And same thing happens
with eggs and dairy protein, both in people with normal
and diseased kidneys. Short-term studies have indicated
that substituting plant proteins like soy for animal protein is
associated with less hyperfiltration and protein leakage, therefore slowing
deterioration of kidney function. However, the long-term effect
has not been adequately studied until this study was
published in 2014. A 6-month double-blind, randomized,
placebo-controlled trial, soy versus dairy protein, and
the consumption of whole soy tended to preserve renal function,
kidney function, compared with milk in individuals with
lowered renal function. Similar results were
reported in diabetics. Even just giving isolated soy protein
appeared to make things better, compared to dairy protein,
which made things worse. Once one’s kidneys have deteriorated
to the point where they’re actively losing protein in the urine,
a plant-based diet may help turn it off and on
like a light switch. Here’s protein leakage on
a standard low sodium diet, switched to a supplemented
vegan diet, low sodium, vegan, low sodium, vegan. What is going on? Why does animal protein cause that
overload reaction, but not plant protein? It appears to be an inflammatory response
triggered by the animal protein. We know this because administration
of a powerful anti-inflammatory drug abolishes the hyperfiltration, protein
leakage response to meat ingestion. Here’s the typical kidney stress
response to a meat meal, but here’s with the anti-inflammatory
drug on board, confirming the role of inflammation in the impact
of animal protein on our kidneys.