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By Stephen Byrnes, PhD,
RNCP
Clinically, I have used low-carbohydrate,
high fat and protein diets to very good effect, especially
with those conditions that are worsened by excessive carbohydrate
intake, e.g., diabetes, chronic fatigue, fibromyalgia, and
heart disease. When properly practiced, low-carb diets are
not harmful.
Some experts believe that excessive protein
consumption, particularly animal protein, can result in heart
disease, stroke, osteoporosis, cancer and kidney stones.
It is excessive carbohydrate intake,
not protein or animal protein intake, that can result in heart
disease and cancer (1).
Readers should note that the type of
diet vegetarian expert advocate are high carbohydrate one
because that is exactly what diets that are low in protein
and fat are. Furthermore, the idea that animal products, specifically
protein, cholesterol, and saturated fatty acids, somehow factor
in causing atherosclerosis, stroke, and/or heart disease is
a popular idea that is not supported by available data, including
the field of lipid biochemistry (2).
The claim that animal protein intake
causes calcium loss from the bones is another popular nutritional
myth that has no backing in nutritional science. The studies
that supposedly showed protein to cause calcium loss in the
urine were NOT done with real, whole foods, but with isolated
amino acids and fractionated protein powders (3).
When studies were done with people eating
meat with its fat, NO calcium loss was detected in the urine,
even over a long period of time (3). Other studies have confirmed
that meat eating does not affect calcium balance (4) and that
protein promotes stronger bones (5). Furthermore, the saturated
fats that many experts believe are so evil are actually required
for proper calcium deposition in the bones (6).
The reason why the amino acids and fat-free
protein powders caused calcium loss while the meat/fat did
not is because protein, calcium, and minerals, require the
fat-soluble vitamins A and D for their assimilation and utilization
by the body. When protein is consumed without these factors,
it upsets the normal biochemistry of the body and mineral
loss results (7). True vitamin A and full-complex vitamin
D are only found in animal fats.
If the protein-causes-osteoporosis theory
teaches us anything, it is to avoid fractionated foods (like
soy protein isolate, something most vegetarians would no doubt
encourage readers to consume) and isolated amino acids, and
to eat meat with its fat.
New evidence shows that women who ate
lots of meat had fewer hip fractures compared to those who
avoided it (8) and that vegan diets place women at a greater
risk for osteoporosis (9).
The claim that protein intake leads to
kidney stones is another popular myth that is not supported
by the facts. Although protein restricted diets are helpful
for people who have kidney disease, eating meat does not cause
kidney problems (10). Furthermore, the fat-soluble vitamins
and saturated fatty acids found in animal foods are pivotal
for properly functioning kidneys (11).
Many experts attempt to explain how meat
supposedly "acidifies" the blood, leading to greater
mineral loss in the urine is also incorrect. Theoretically,
the sulfur and phosphorus in meat can form an acid when placed
in water, but that does not mean that is what happens in the
body.
Actually, meat provides complete proteins
and vitamin D (if the fat or skin is eaten), both of which
are needed to maintain proper acid-alkaline balance in the
body. Furthermore, in a diet that includes enough magnesium
and vitamin B6 and restricts simple sugars, one has little
to fear from kidney stones (12).
Animal foods like beef, poultry, and
lamb are good sources of both nutrients as any food and nutrient
content table will show. It also goes without saying that
high protein/fat and low-carbohydrate diets are devoid of
sugar.
Some believe that the weight loss on
high-protein diets is mostly from water loss is strange given
that low-carb proponents like Robert Atkins, MD, tell their
devotees to drink lots of water while on the diet. Initially,
there is a water loss (as with any diet), but the high water
intake afterwards would certainly offset any more drastic
"water losses."
Others believe that weight loss occurs
on high protein/fat diets because the person eats less food
because he or she gets fuller faster on fat. Given that fat
has more than twice as many calories than either protein or
carbohydrate, this explanation is far from satisfactory.
In other words, you may not eat as many
carbohydrates as you did before you went on the high protein
diet, but because you're ingesting more fat, which has over
twice as many calories as carbohydrate, your actual caloric
intake is likely to stay the same or be higher than it was
before.
Some claim that plant-based proteins
like those found in soy, lower LDL cholesterol and raises
HDL (good) cholesterol. This prevents the build up of arterial
plaque which leads to atherosclerosis and heart disease, thus
reducing the risk of heart attack and stroke.
This is yet another nutritional fantasy
that although popular, is not true. The HDL/LDL theory has
been thoroughly debunked by a number of prominent researchers
(13) and LDL serves many useful functions in the body -- there
is nothing "bad" about it (14).
Cholesterol is actually used by the body
as an antioxidant (15); vegetarian diets do not protect against
atherosclerosis or heart disease (16); and female vegans have
higher rates of death from heart disease than female meat
eaters (17).
Others contend that vegetable-protein
diets enhance calcium retention in the body. This is simply
wrong as "vegetable proteins" do not contain the
fat-soluble vitamins A and D which are needed to assimilate
calcium (and protein and other minerals). Furthermore, numerous
plant compounds like oxalates and phytates inhibit calcium
absorption.
Unfermented soy products, in particular,
are noted for their high phytic acid content and phytates
block mineral absorption (18).
Many experts advise us to replace vegetable
protein for animal protein and unsaturated fats "like
olive and canola oils" for saturated fats, is dubious
at best and dangerous at worst. A number of recent and prior
studies catalog the veritable witches brew of toxins found
in processed soy products (19) and canola oil has caused vitamin
E deficiencies in lab animals (20).
Canola oil is also quite susceptible
to rancidity due to its high level of alpha-linolenic acid;
in the deodorization process used with canola oil, harmful
trans-fatty acids are created (21).
Lastly, studies have not born out the
claims that vegetarians have lower cancer rates than the general
population. A large study on vegetarian California 7th Day
Adventists showed that, while the Adventists had slightly
lower rates for some cancers, their rates of malignant melanoma;
Hodgkin's disease; and uterine, prostate, endometrial, cervical,
ovarian, and brain cancers were higher than the general population,
some quite significantly. In the paper, the authors wrote
that,
Meat consumption, however, was not associated
with a higher cancer risk.
And that,
No significant association between breast
cancer and a high consumption of animal fats or animal products
in general was noted. (22)
Indeed, Dr. Emmanuel Cheraskin's survey
of 1040 dentists and their wives showed that those with the
fewest health problems as measured by the Cornell Medical
Index had the MOST protein in their diets (23).
The facts are that high-protein diets,
when consumed in balance with enough water, fat and fat-soluble
vitamins, and nutritional factors from non-starchy vegetables,
ARE healthy.
They are not guilty of the things many
health experts blame on them. Minimally processed animal foods
like beef and lamb are healthy foods that are rich in a number
of nutrients that protect and enhance several body systems:
taurine; carnitine; creatine; glutathione; vitamins A; D;
several of the B-complex, including B6 and B12; minerals like
chromium, magnesium, sulfur, iron, zinc, and phosphorus; complete
proteins; and coenzyme Q10, needed for a healthy heart.
If readers want to get an accurate assessment
of lower-carbohydrate diets, they should check out reliable
books on the subject. (24)
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