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Dem Bones:
Do High Protein Diets Cause Bone Loss?
By Sally Fallon and Mary G. Enig, PhD
An estimated 15 to 20 million Americans suffer from osteoporosis--thinning
of the bones leading to back pain, increased fractures, and frailty,
frequently with extensive suffering. One theory proposed to explain
its prevalence in the US is a diet that is high in protein, from excessive
consumption of meat.
The protein theory was first presented in 19681 and followed
up in 1972 with a study comparing bone density of vegetarians and meat
eaters.2 Twenty-five British lacto-ovo vegetarians were matched
for age and sex with an equal number of omnivores. Bone density, determined
by reading X-rays of the third finger metacarpal, was found to be significantly
higher in the vegetarians. Two years later, a study on North Alaskan
Eskimos reported that bone loss, determined by a technique called direct
photon absorptiometry, was significantly greater in Eskimos than in
whites, and began at an earlier age.3 Although growth patterns
and bone densities in children were similar for both groups, by age
70, Eskimos were found to have bone densities 15% below comparable whites,
with Eskimos females at 30% below comparable whites. The authors of
the study attribute the decline in bone mass to the high protein diet
of the Eskimos, especially its high meat content. Some studies with
animals, as well as further studies with humans, given diets high in
protein also indicate a greater loss of calcium and thinner bones than
controls on low protein regimes.
But the pioneering research of Dr. Weston Price indicates that we
should not accept the protein theory without further study. Dr. Price
found many groups throughout the world subsisting on high meat diets.
Although he did not directly study bone density in these peoples, he
did study their teeth. He found that groups on high meat diets--including
Alaskan Eskimos--had a high immunity to tooth decay, were sturdy and
strong, and virtually free from degenerative disease. Groups subsisting
mainly on plant foods were less robust and had more tooth decay. Pre-Columbian
skeletons of American Indians whose diets consisted largely of meat
show no osteoporosis, while those of Indians on largely vegetarian diets
indicate a high incidence of osteoporosis and other types of bone degeneration.
The implication of Dr. Price's research and other anthropoligical studies
is that high meat diets protect against osteoporosis. How do
we explain this discrepancy?
The research of Dr. Herta Spencer, of the Veterans Administration
Hospital in Hines Illinois, supplies us with clues. She notes that the
animal and human studies that correlated calcium loss with high protein
diets used isolated, fractionated amino acids from milk or eggs.4
Her studies show that when protein is given as meat, subjects do not
show any increase in calcium excreted, or any significant change in
serum calcium, even over a long period.5 Other investigators
found that a high protein intake increased calcium absorption when dietary
calcium was adequate or high, but not when calcium intake was a low
500 mg per day.6
The textbooks tell us that the body needs vitamin D for calcium utilization,
and vitamin A for both calcium and protein assimilation. Protein given
as a powder lacks these fat-soluble co-factorsthat the body can use
to build and maintain healthy bones.
Synthetic vitamin D, on the other hand, can cause hypercalcemia, a
disturbance of calcium equilibrium leading to excessive blood calcium
and calcification of soft tissues.7 Synthetic vitamin D added
to commercial milk does not have the same beneficial effect as vitamin
D from cod liver oil in preventing rickets and strengthening the bones.
Fats, especially animal fats, also supply usable vitamin K. This nutrient
is associated with blood clotting--individuals who lack the ability
to use vitamin K suffer from hemophilia and risk uncontrolled bleeding
when injured. But Vitamin K also plays an important role in bone metabolism.
Vitamin K is more available in dairy fats than in the oils found in
green vegetables. Studies indicate that vitamin K is more completely
absorbed from vegetables consumed with butter than with vegetables eaten
plain.8 Vitamin K is also manufactured by intestinal flora.
Use of antibiotics can inhibit vitamin K production, leading to bone
loss. Consumption of lacto-fermented foods such as yoghurt and old fashioned
sauerkraut promotes the growth of beneficial flora in the intestines,
and hence contributes to healthy bones.
Fat soluble vitamin E also plays a role in promoting bone health,
by protecting the calcium depositing mechanism from free radical disruption.
In a recent study, investigators at Purdue University found that high
levels of free radicals from omega-6 linoleic acid (found principally
in corn, soy and safflower oils) interfered with bone formation, but
that vitamin E gave needed protection in a diet high in polyunsaturates.9
In addition, they found that high levels of saturated fat also gave
protection. That's right, the much-maligned saturated fats, found in
tropical oils, butter and other animal fats, play an important role
in bone modeling. This may be a major reason that population groups
in tropical areas, where coconut and palm oils form a major component
of the diet, have very little osteoporosis.
Bone loss in women coincides with diminution of estrogen and progesterone
at the onset of menopause. But archeological evidence indicates that
menopause does not necessarily initiate osteoporosis. Human skeletons
of Huguenot women ages fifteen to eighty-nine recently exhumed in London
showed little difference in bone density between premenopausal and post
menopausal women.10 Once again, the role of animal fats in
the diet can explain this contradiction. Vitamin A in animal fats is
absolutely essential for the health of the entire glandular system,
and hence the continued production of regulating hormones throughout
life. Hormone replacement often recommended for the prevention of osteoporosis
is not an ideal substitute for the natural hormones produced in properly
nourished bodies. Estrogen is also synthesized in the adipose (fat)
tissue.11 Perhaps this is why women naturally gain some weight
at menopause. The extra body fat supplies them with additional estrogen
and protects them from bone loss. Maintaining a svelte figure in middle
age, either through weight loss or liposuction, does not necessarily
confer health benefits. Very thin women are much more at risk for bone
loss than those who allow themselves to enjoy good, wholesome food and
become pleasingly plump.12 Many women smoke cigarettes to
keep their weight down, a habit that lowers estrogen concentration in
the blood stream and inhibits its effects.13
Only a rich, wholesome and varied diet can supply the many nutrients
needed for the complex process that maintains the integrity of our bones.
Dairy products, vegetables, nuts, meat and old fashioned bone broths
supply calcium. Dr. Spencer's research indicates that post-menopausal
women need about 1200 mg of calcium per day--400 more that the recommended
daily allowance of 800 mg.14 One quart of whole milk, or
six ounces of whole natural cheese supply the optimum 1200 mg of calcium.
Individuals with a poor tolerance to milk products must take extra care
to obtain sufficient dietary calcium. Fish, chicken or beef broth, prepared
with a little vinegar to pull calcium from the bones, are excellent
sources, and have supplied easily assimilated calcium to pre-industrialized
peoples throughout the globe. Leafy green vegetables and grains, nuts
and seeds are also good sources if properly prepared. Vegetables and
grains should be consumed with animal fats like butter or eggs; and
nuts, legumes and grains should be soaked, sprouted or sour leavened
to neutralize phytic acid, a substance that can block calcium absorption.15
The "acid-ash" of meat is given as the reason high meat diets cause
bone loss. But meats also supply phosphorus, which counteracts this
acidity. Phosphorus is needed for the phosphate component of bone matter.
Meats are also excellent sources of vitamin B12, which plays a recently
discovered but little understood role in maintaining the integrity of
the bones.16
Plant foods such as fruits, especially apples, nuts and grains supply
boron, needed for the conversion of vitamin D to its active form, and
for the formation of estrogen. Iodine found in natural sea salt, sea
foods and butter helps maintain healthy ovaries and thyroid gland, both
of which play a role in maintaining bone integrity. Magnesium, found
in whole foods, also contributes to bone health as does natural fluoride,
present in hard water as calcium fluoride. Chromium may also contribute
to bone health by normalizing insulin activity. Type I diabetics are
prone to osteoporosis. Chromium picolinate has been found to reduce
the amount of calcium excreted in the urine and therefore may protect
against bone loss.17 Refined carbohydrates such as sugar
and white flour can cause chromium deficiency.
But sodium fluoride added to drinking water is one of a number of
substances that is harmful to our bones. It causes an apparent increase
in bone mass, but the bone structure is abnormal and weak.18
Recent studies indicate that hip fractures are more common in areas
where water is fluoridated.19
The late distinguished physician, Dr. Melvin Page, demonstrated that
sugar consumption upsets the natural homeostasis of calcium and phosphorus
in the blood. Normally, these minerals exist in a precise ratio of ten
to four. Sugar consumption causes serum phosphorus to decrease and calcium
to rise.20 The excess serum calcium, which comes from the
bones and teeth, cannot be fully utilized because phosphorus levels
are too low. It is excreted in the urine or stored in abnormal deposits
such as kidney stones and gallstones. Caffeine also upsets the natural
balance of calcium and phosphorus, and causes increased calcium to be
excreted in the urine. Phosphoric acid in soft drinks is a major cause
of calcium deficiency in children and osteoporosis in adults.21
Aluminum from antacids, cans and pollution also contributes to bone
loss.22
Osteoporosis is often associated with excess consumption of alcohol.23
This is the likely explanation of bone loss in Eskimos, who are highly
prone to alcoholism. The fact that the Eskimo is an obligate carnivore
may also explain his susceptibility to both alcoholism and bone loss.
Isolated groups like Eskimos and Irish sea coast peoples, whose traditional
diet has been rich in marine oils, lack the desaturating enzymes needed
to produce very long, highly unsaturated fatty acids needed for prostaglandin
production.24 People with arctic or sea coast ancestry would
be wise to supplement their diet with cod liver oil, a rich source of
very long chain fatty acids needed for virtually every metabolic process.
Even small changes in the native diet of carnivorous populations render
them vulnerable to degenerative disease like osteoporosis and alcoholism.
A recent article on the Canadian Inuits indicates that commercial foods
like jam, white bread and peanut butter have replaced some of the meat
in their diet, even while they continue to maintain a traditional lifestyle.25
The 1972 study comparing British vegetarians and omnivores calls for
additional comment. Bone density determinations through absorptiometry
or X-ray are highly subject to error26, especially in unblinded
studies where researchers may be biased towards obtaining pre-determined
results. Subjects were matched merely for age, height and sex, but not
for body composition and dietary habits such as smoking and sugar, coffee
and alcohol consumption. A group of omnivores that smokes, drinks and
indulges in a calcium-poor diet of refined carbohydrates will naturally
have more of a tendency to bone loss than a group of health-conscious
lacto-ovo vegetarians who consume plenty of dairy products. (British
vegetarians do, in fact, tend to be very health conscious, avoiding
not only meat but also alcohol, cigarettes, coffee and soft drinks.
Unlike American vegetarians, they understand the importance of calcium-rich
whole dairy products in the diet and eat plentifully of milk, cheese,
butter and eggs.) When researchers compare the effects of high-meat
diets to normal diets in the same person, no adverse effects
are found, even over extended periods of time.27
Individuals who find they do better on high meat diets need not, therefore,
worry about osteoporosis, as long as their diet includes complementary
animal fats, plenty of calcium and a variety of other properly prepared
whole foods.
About the Authors
Sally
Fallon is the author of
Nourishing Traditions: The Cookbook that Challenges Politically Correct
Nutrition and the Diet Dictocrats (with Mary G. Enig, PhD), a well-researched,
thought-provoking guide to traditional foods with a startling message: Animal
fats and cholesterol are not villains but vital factors in the diet, necessary
for normal growth, proper function of the brain and nervous system, protection
from disease and optimum energy levels. She joined forces with Enig again to
write Eat Fat, Lose Fat, and has authored numerous articles on the
subject of diet and health. The President of the Weston A. Price Foundation
and founder of A Campaign for Real Milk,
Sally is also a journalist, chef, nutrition researcher, homemaker, and community
activist. Her four healthy children were raised on whole foods including butter,
cream, eggs and meat.
Mary
G. Enig, PhD is an expert of international renown in the field of lipid
biochemistry. She has headed a number of studies on the content and effects of
trans fatty acids in America and Israel, and has successfully challenged
government assertions that dietary animal fat causes cancer and heart disease.
Recent scientific and media attention on the possible adverse health effects of
trans fatty acids has brought increased attention to her work. She is
a licensed nutritionist, certified by the Certification Board for Nutrition Specialists,
a qualified expert witness, nutrition consultant to individuals, industry and
state and federal governments, contributing editor to a number of scientific publications,
Fellow of the American College of Nutrition and President of the Maryland Nutritionists
Association. She is the author of over 60 technical papers and presentations,
as well as a popular lecturer. Dr. Enig is currently working on the exploratory
development of an adjunct therapy for AIDS using complete medium chain saturated
fatty acids from whole foods. She is Vice-President of the Weston A Price Foundation
and Scientific Editor of Wise Traditions as well as the author of Know
Your Fats: The Complete Primer for Understanding the Nutrition of Fats, Oils,
and Cholesterol, Bethesda Press, May 2000. She is the mother of three healthy
children brought up on whole foods including butter, cream, eggs and meat. Notes
- A Wachman and D S Bernstein, "Diet and osteoporosis" Lancet
1968 1:958
- Frey R Ellis, et al, "Incidence of osteoporosis in vegetarians
and omnivores" American Journal of Clinical Nutrition, June
1972, 25:555-558
- Richard B Mazess and Warren Mather, "Bone mineral content of North
Alaskan Eskimos" American Journal of Clinical Nutrition, September
1974 2:916-925
- Herta Spencer and Lois Kramer, "Factors contributing to osteoporosis",
Journal of Nutrition, 1986 116:316-319
- Herta Spencer and Lois Kramer, "Further studies of the effect of
a high protein diet as meat on calcium metabolism", American Journal
of Clinical Nutrition, June 1983 37 (6):924-929
- HM Linkswiler, et al, "Calcium retention of young adult males as
affected by level or protein and of caclcium intake", Trans. N.
Y. Acad. Sci, 1974 36:333
- Judith A DeCava, The Real Truth About Vitamins and Antioxidants,
Brentwood Academic Press, Columbus Georgia, pp 102-113.
- C Vermeer et al, "Role of vitamin K in bone metabolism", Annual
Review of Nutrition 1995 15:1-22
- BA Watkins et al, "Importance of Vitamin E in Bone Formation and
in Chondrocyte Function" Purdue University, W. Lafayette, IN 47907
- B Lees et al, "Differences in proximal femur bone density over
two centuries", Lancet March 1993, 341:673-675
- M E Nelson, "Hormone and bone mineral status in endurance-trained
and sedentary postmenopausal women" Journal of Clinical Endocrinology
and Metabolism May 1988, 66(5):927-933
- R N Baumgartner et al, "Associations of fat and muscle masses with
bone mineral in elderly men and women", American Journal of Clinical
Nutrition 1996 63:365
- National Institute of Health Consensus Conference: "Osteoporosis"
Journal of the American Medical Association August 1984 252(6):799-802
- Herta Spencer and Lois Kramer, "Osteoporosis: Calcium, Fluoride
and Aluminum Interactions", Journal of the American College of
Nutrition 1985 4:121-128
- Lindsey H Allen, "Calcium absorption and requirements during the
life span", Nutrition News, February 1984 47(1):1-3
- M E Melton and M L Kochman, "Reversal of severe osteoporosis with
vitamin B12 and etidronate therapy in a pateint with pernicious anemia",
Metabolism: Clinical & Experimental 1994 43 (4) 468-9
- McCarthy, Med Hypotheses 1995 45:241-246
- Yiamouyiannis, John, Fluoride, The Aging Factor, Health
Action Press, 1986
- C Cooper et al, "Water fluoridation and hip fracture", Journal
of the American Medical Association, July 1991, 19(32):513-514
- Melvin E Page, Degeneration, Regeneration 1949. Available
from the Price Pottenger Nutrition Foundation, San Diego, CA
- E Mazariegos-Ramos et al, "Consumption of soft drinks with phosphoric
acid as a risk factor for the development of hypocalcemia in children:
A case control study", Journal of Pediatrics 1995 126:940-942
- Herta Spencer and Lois Kramer, "Osteoporosis: Calcium, Fluoride
and Aluminum Interactions", Journal of the American College of
Nutrition 1985 4:121-128
- Herta Spencer, et al, "Chronic Alcoholism: Frequently Overlooked
Cause of Osteoporosis in Men", The American Journal of Medicine,
March 1986 80:393-397
- D F Horrobin, Reviews in Pure and Applied Pharmacological Sciences
Vol 4, 1983 Freund Publishing House 339-383
- Yvette Cardozo and Bill Hirsch "Northern Exposure: An Inuit Adventure"
Relax, January 1996 21-27
- Alternative Medicine, The Definitive Guide, Future Medicine
Publishing, Inc., Puyallup, Washington, p 776
- Herta Spencer, et al "Do Protein and Phosphorus Cause Calcium Loss?"
American Institute of Nutrition, 1988:657-660
First published in Price-Pottenger Nutrition Foundation
quarterly journal, (619) 574-7763.
© 2000 Sally Fallon and Mary G. Enig. All Rights Reserved.
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