Cow's
milk may indeed be the all time great miracle
food since it provides us with the basic vitamins,
iodine, calcium, proteins, and other nutrients
necessary for a strong healthy body and mind.
(The scientific name for a dairy cow is Bos taurus.)
Cow's milk, the basis for all other dairy products
(which by weight has an average fat content of
3.5% ), promotes strong bones by being an excellent
source of vitamin D, a very good source of calcium,
and a good source of vitamin K--three nutrients
essential to bone health. In addition, cow's milk
is a very good source of iodine, a mineral essential
for thyroid function; and vitamin B12 and riboflavin,
which are necessary for cardiovascular health
and energy production.
Cow's milk is also a good source of biotin and
pantothenic acid, two other B vitamins important
for energy production; vitamin A, a critical nutrient
for immune function; potassium and magnesium,
for cardiovacular health; selenium, a cancer-preventive
trace mineral; and thiamin, a B-vitamin important
for cognitive function, especially memory.
Milk produced by grass fed cows also contains
a beneficial fatty acid called conjugated linoleic
acid (CLA). Researchers who conducted animal studies
with CLA found that this fatty acid inhibits several
types of cancer in mice. In vitro (test tube)
studies indicate this compound kills human skin
cancer, colorectal cancer and breast-cancer cells.
Other research on CLA suggests that this beneficial
fat may also help lower cholesterol and prevent
atherosclerosis.
Calcium - A Mineral for a Lot More than Strong
Bones
Cow's milk may be best known as a very good source
of calcium. Calcium is widely recognized for its
role in maintaining the strength and density of
bones. In a process known as bone mineralization,
calcium and phosphorous join to form calcium phosphate.
Calcium phosphate is a major component of the
mineral complex (called hydroxyapatite) that gives
structure and strength to bones. A cup of cow's
milk supplies 29.7% of the daily value for calcium
along with 33.1% of the DV for phosphorus.
Building bone is, however, far from all that calcium
does for us. In recent studies, this important
mineral has been shown to:
-
Help protect colon cells from cancer-causing
chemicals
-
Help prevent the bone loss that can occur
as a result of menopause or certain conditions
such as rheumatoid arthritis
-
Help prevent migraine headaches in those who
suffer from them
-
Reduce PMS symptoms during the luteal phase
(the second half) of the menstrual cycle
-
Help prevent childhood obesity(January 29,
2004)
A prospective study published in the December
issue of the Journal of the American Dietetic
Association gives parents yet another reason to
regularly include low-fat dairy products such
as low fat cow's milk in their children's healthy
way of eating, given the rate at which childhood
obesity is rising in the West: consumption of
calcium-rich foods was found to be negatively
correlated with body fat.
According to the New England Journal of Medicine,
childhood obesity has reached epidemic proportions
in the U.S., with the number of overweight children
more than doubling in the last three decades,
and the International Obesity Task Force recently
reported that in the UK, childhood obesity is
already three times higher than it was just over
10 years ago.
In this prospective longitudinal study, researchers
at the University of Tennessee assessed the height,
weight and dietary intake of 52 children (27 girls
and 25 boys), starting when the children were
2 months of age and following them for 8 years.
Dietary calcium and polyunsaturated fat intake
were negatively related to per cent of body fat,
while total dietary fat or saturated fat intake
and amount of sedentary activity (hours/day) were
positively correlated.
Earlier
studies have also reported a negative association
between calcium intake and body fat accumulation
during childhood and between calcium intake and
body weight at midlife. Each 300 mg increment
in regular calcium intake has been consistently
associated with approximately 1 kg less body fat
in children and 2.5-3.0 kg lower body weight in
adults. Taken together these data suggest that
increasing calcium intake by the equivalent of
two dairy servings per day could reduce the risk
of becoming overweight substantially, perhaps
by as much as 70 percent. The current study's
lead author, Dr. Jean Skinner, advised that children
should be encouraged to regularly eat calcium-rich
foods, such as low fat milk and yoghurt and to
increase physical activity. In addition, Dr. Skinner
recommended that carbonated soft drinks and other
nutrient-poor beverages be restricted since children's
intake of carbonated beverages and other sweetened
drinks was found to be negatively related to their
calcium intake.(January 29, 2004)
Calcium also plays a role in many other vital
physiological activities, including blood clotting,
nerve conduction, muscle contraction, regulation
of enzyme activity, cell membrane function and
blood pressure regulation. Because these activities
are essential to life, the body utilizes complex
regulatory systems to tightly control the amount
of calcium in the blood, so that sufficient calcium
is always available. As a result, when dietary
intake of calcium is too low to maintain adequate
blood levels of calcium, calcium stores are drawn
out of the bones to maintain normal blood concentrations--which
is where vitamin D comes in.
Vitamin D Ensures Calcium's Availability
Although typically categorized as a fat-soluble
vitamin, vitamin D actually functions more like
a hormone than a vitamin. Calcitriol, the most
metabolically active form of vitamin D, works
with parathyroid hormone (PTH) to maintain proper
levels of calcium in the blood. In addition, calcitriol
participates in the regulation of cell proliferation,
differentiation, and growth, which suggests that
vitamin D may play a role in the prevention and
treatment of various cancers. A cup of cow's milk
supplies 48.8% of the daily value for this important
vitamin.
More Help for Bone Health
The vitamin K provided by cow's milk is also important
for maintaining strong bones. Vitamin K1 activates
osteocalcin, the major non-collagen protein in
bone. Osteocalcin anchors calcium molecules inside
of the bone. Therefore, without enough vitamin
K1, osteocalcin levels are inadequate, and bone
mineralization is impaired. A cup of cow's milk
provides 15.5% of the daily value for vitamin
K.
A Good Source of Protein
Cow's milk is a good source of low-cost high-quality
protein, providing 8.1 grams of protein (16.3%
of the daily value for protein) in one cup. The
structure of humans and animals is built on protein.
We rely on animal and vegetable protein for our
supply of amino acids, and then our bodies rearrange
the nitrogen to create the pattern of amino acids
we require.
B vitamins for Energy and Cardiovascular Protection
Cow's milk is a very good source of vitamin B12
and riboflavin. Both B vitamins are important
for energy production. Vitamin B12 plays a pivotal
role as a methyl donor in the basic cellular process
of methylation, through which methyl groups are
transferred from one molecule to another, resulting
in the formation of a wide variety of very important
active molecules. When levels of B12 are inadequate,
the availability of methyl groups is also lessened.
One result of the lack of methyl groups is that
molecules that would normally be quickly changed
into other types of molecules not only do not
change, but accumulate. One such molecule, homocysteine,
is so damaging to blood vessel walls that high
levels are considered a significant risk factor
for cardiovascular disease.
In addition to its function as a methyl donor,
vitamin B12 plays an essential role in the production
of red blood cells and prevention of anemia, is
also needed for nerve cells to develop properly,
and helps cells metabolize protein, carbohydrate,
and fat.
Riboflavin (vitamin B2) plays at least two important
roles in the body's energy production. When active
in energy production pathways, riboflavin takes
the form of flavin adenine dinucleotide (FAD)
or flavin mononucleotide (FMN). In these forms,
riboflavin attaches to protein enzymes called
flavoproteins that allow oxygen-based energy production
to occur. Flavoproteins are found throughout the
body, particularly in locations where oxygen-based
energy production is constantly needed, such as
the heart and other muscles.
Riboflavin's other role in energy production is
protective. The oxygen-containing molecules the
body uses to produce energy can be highly reactive
and can inadvertently cause damage to the mitochondria
and even the cells themselves. In the mitochondria,
such damage is largely prevented by a small, protein-like
molecule called glutathione. Like many "antioxidant"
molecules, glutathione must be constantly recycled,
and it is vitamin B2 that allows this recycling
to take place. (Technically, vitamin B2 is a cofactor
for the enzyme glutathione reductase that reduces
the oxidized form of glutathione back to its reduced
version.) Riboflavin been shown to be able to
reduce the frequency of migraine headaches in
people who suffer from them.
One cup of cow's milk supplies 37.1% of your daily
needs for vitamin B12 and 36.4% of the DV for
riboflavin.
Promote Healthy Thyroid Function
Cow's milk is a very good source of iodine, which
as a component of the thyroid hormones thyroxine
(T4) and triiodothyronine (T3), is essential to
human life. The thyroid gland adds iodine to the
amino acid tyrosine to create these hormones.
Without sufficient iodine, your body cannot synthesize
them. Because these thyroid hormones regulate
metabolism in every cell of the body and play
a role in virtually all physiological functions,
an iodine deficiency can have a devastating impact
on your health and well-being. A common sign of
thyroid deficiency is an enlarged thyroid gland,
commonly called a goiter. Goiters are estimated
to affect 200 million people worldwide, and in
all but 4% of these cases, the cause is iodine
deficiency. One cup of dairy contains 39% of the
daily value for iodine.
Biotin--An Energy-Boosting B-Vitamin
Cow's milk is a good source of biotin, a B-vitamin
involved in the metabolism of both sugar and fat,
so drinking it can help promote energy production,
skin health and nervous system function.
In sugar metabolism, biotin helps move sugar from
its initial stages of processing on to its conversion
into usable chemical energy. For this reason,
muscle cramps and pains related to physical exertion,
which can be the result of the body's inability
to use sugar efficiently as fuel, may signal a
biotin deficiency.
Many of the classic biotin deficiency symptoms
involve skin-related problems, and the role of
biotin in fat synthesis is often cited as a reason
for this biotin-skin link. Biotin is required
for the function of an enzyme in the body called
acetyl Co-A carboxylase, which puts together the
building blocks for the production of fat in the
body. In infants, the most common biotin-deficiency
symptom is cradle cap. In adults, the equivalent
skin condition is called seborrheic dermatitis.
Because glucose and fat are used for energy within
the nervous system, biotin also functions as a
supportive vitamin in this area. Numerous nerve-related
symptoms have been linked to biotin deficiency
including lack of muscle coordination (ataxia),
and lack of good muscle tone (hypotonia). A cup
of cow's milk provides 16.3% of the daily value
for biotin.
Vitamin A
Vitamin A is critically importance for the health
of epithelial and mucosal tissues, the body's
first line of defense against invading organisms
and toxins. The epithelium is a layer of cells
forming the epidermis of the skin and the surface
layer of mucous and serous membranes. All epithelial
surfaces including the skin, vaginal epithelium,
and gastrointestinal tract rely upon vitamin A.
When vitamin A status is inadequate, keratin is
secreted in epithelial tissues, transforming them
from their normally pliable, moist condition into
stiff dry tissue that is unable to carry out its
normal functions, and leading to breaches in epithelial
integrity that significantly increase susceptibility
to the development of allergy and infection.
So, when our vitamin A levels are low, we are
much more susceptible to infections such as recurrent
ear infections or frequent colds, or we may wind
up with an immune system that is overactive, leading
to autoimmune diseases like rheumatoid arthritis.
In fact, low vitamin A levels in Third World countries
are blamed for the huge amounts of complications
and deaths due to childhood diseases like measles.
When children in these areas are given adequate
amounts of vitamin A, the number of deaths from
these illnesses drops dramatically, just one demonstration
of the importance of vitamin A for strong immune
function. Drink a cup of dairy, and you will receive
12.5% of the daily value for vitamin A.
Protect Your Heart with Potassium and Magnesium
An important electrolyte involved in nerve transmission
and the contraction of all muscles including the
heart, potassium is essential for maintaining
normal blood pressure and heart function. Cow's
milk can promote your cardiovascular health by
being a good source of not only potassium, but
magnesium, too. A one cup serving provides 10.8%
of the daily value for potassium along with 10.4%
of the daily value for magnesium.
Magnesium helps regulate nerve and muscle tone
by balancing the action of calcium. In many nerve
cells, magnesium serves as Nature's own calcium
channel blocker, preventing calcium from rushing
into the nerve cell and activating the nerve.
By blocking calcium's entry, magnesium keeps our
nerves (and the blood vessels and muscles they
ennervate) relaxed. If our diet provides us with
too little magnesium, however, calcium can gain
free entry, and the nerve cell can become overactivated,
sending too many messages and causing excessive
contraction. Insufficient magnesium can thus contribute
to high blood pressure, muscle spasms (including
spasms of the heart muscle or the spasms of the
airways symptomatic of asthma), and migraine headaches,
as well as muscle cramps, tension, soreness and
fatigue.
In addition, magnesium, as well as calcium, is
necessary for healthy bones. About two-thirds
of the magnesium in the human body is found in
our bones. Some helps give bones their physical
structure, while the rest is found on the surface
of the bone where it is stored for the body to
draw upon as needed.
Cancer-Protective Selenium
Cow's milk is also a good source of the trace
mineral, selenium. Selenium is of fundamental
importance to human health. It is an essential
component of several major metabolic pathways,
including thyroid hormone metabolism, antioxidant
defense systems, and immune function. Accumulated
evidence from prospective studies, intervention
trials and studies on animal models of cancer
have suggested a strong inverse correlation between
selenium intake and cancer incidence.
Several mechanisms have been suggested to explain
the cancer-preventive activities of selenium.
Selenium has been shown to induce DNA repair and
synthesis in damaged cells, to inhibit the proliferation
of cancer cells, and to induce their apoptosis,
the self-destruct sequence the body uses to eliminate
worn out or abnormal cells. In addition, selenium
is incorporated at the active site of many proteins,
including glutathione peroxidase, which may be
the most important for cancer protection. One
of the body's most powerful antioxidant enzymes,
glutathione peroxidase is used in the liver to
detoxify a wide range of potentially harmful molecules.
When levels of glutathione peroxidase are too
low, these toxic molecules are not disarmed and
wreak havoc on any cells with which they come
in contact, damaging their cellular DNA and promoting
the development of cancer cells. One cup of cow's
milk supplies 9.8% of the daily value for selenium.
Maintain Your Memory with Thiamin (Vitamin
B1)
Dairy is a good source of thiamin, providing 9.1%
of the daily value for this nutrient in a cup.
Thiamin is an integral participant in enzymatic
reactions central to energy production and is
also critical for brain cell/cognitive function.
This is because thiamin is needed for the synthesis
of acetylcholine, a neurotransmitter essential
for memory, whose lack has been found to be a
significant contributing factor in age-related
impairment in mental function (senility) and Alzheimer's
disease. In fact, Alzheimer's disease is clinically
characterized by a decrease in acetylcholine levels.
Don't forget to make dairy a part of your healthy
diet.
History
The practice of drinking the cow's dairy products
is ancient, thought to date back as early as 6,000
- 8,000 B.C. dairy products were so highly valued
in ancient Egypt that only the very wealthy could
afford to consume them. Beginning in the 5th century
A.D., the dairy products of cows and sheep began
to be especially prized in Europe, but it wasn't
until the 14th century that the demand for cow's
dairy products began to outpace that of sheep.
Dairy cows did not make an appearance in America
until the early 17th century, when they were brought
over from Europe. Pasteurization began in the
very late 19th century, although it wasn't until
the mid-20th century that a more refined technique,
ultra-high temperature pasteurization, was introduced.
Safety Tips
Although allergic reactions can occur to virtually
any food, research studies on food allergy consistently
report more problems with some foods than with
others. Common symptoms associated with an allergic
reaction to food include: chronic gastrointestinal
disturbances; frequent infections, e.g. ear infections,
bladder infections, bed-wetting; asthma, sinusitis;
eczema, skin rash, acne, hives; bursitis, joint
pain; fatigue, headache, migraine; hyperactivity,
depression, insomnia.
Individuals who suspect food allergy to be an
underlying factor in their health problems may
want to avoid commonly allergenic foods. Cow's
dairy products are one of the foods most commonly
associated with allergic reactions. Other foods
commonly associated with allergic reactions include:
beef, wheat, eggs, soybeans, oranges, corn, pork,
chicken, peanuts, yeast, strawberry, tomato, and
spinach. These foods do not need to be eaten in
their pure, isolated form in order to trigger
an adverse reaction. For example, yogurt is also
a common allergenic food, even though the it has
been processed and fermented in order to make
the yogurt. Ice cream made from cow cream would
be an equally good example. Lactose, or dairy
sugar, forms about 4.7% of the solids. Many individuals
lack the enzyme, lactase, that is needed to digest
lactose. For this reason, food intolerances to
dairy products are among the most common food
intolerances seen by healthcare practitioners.
Cows may be treated with a compound called recombinant
bovine growth hormone rBGH. Canada has banned
the use of this hormone in cows, based on research
from Canadian scientists. Their report on rBGH
noted that cows injected with the growth hormone
reportedly have a 25 percent increase in risk
of mastitis, an 18 percent increase in the risk
of infertility and a 50 percent increase in the
risk of lameness. Another independent Canadian
scientific committee found there was no direct
risk to human health. Several U.S. groups have
opposed the use of the hormone. One concern is
that cows with mastitis are treated with antibiotics.
The best way to ensure that you buy dairy that
has not been treated with rBGH is to buy organic
dairy products.
References
* Ciampa L. Consumer groups seek to ban growth
hormone for dairy cows. Linda Ciampa CNN.com.
June 15 1999.
* Ensminger AH, Esminger M. K. J. e. al. Food
for Health: A Nutrition Encyclopedia. Clovis,
California: Pegus Press; 1986.
* Hajjar IM, Grim CE, Kotchen TA. Dietary calcium
lowers the age-related rise in blood pressure
in the United States: the NHANES III survey. J
Clin Hypertens 2003 Mar-2003 Apr 30; 5(2):122-6.
* Heaney RP, Davies KM, Barger-Lux MJ. Calcium
and weight: clinical studies. J Am Coll Nutr.
2002 Apr; 21(2): 152S-155S. .
* Jiang J, Wolk A, Vessby B. Relation between
the intake of fat and the occurrence of conjugated
linoleic acid in human adipose tissue. Am J Clin
Nutr 1999 Jul;70(1):21-7.
* Margen S and the Editor, Univ of California
at Berkley Wellness Letter. The Wellness Encyclopedia
of food and nutrition. New York: Health Letter
Associates 1992.
* Skinner JD, Bounds W, Carruth BR, Ziegler P.
Longitudinal calcium intake is negatively related
to children's body fat indexes. . J Am Diet Assoc.
2003 Dec;103(12):1626-31.
* Wood, Rebecca. The Whole Foods Encyclopedia.
New York, NY: Prentice-Hall Press; 1988.
* Yeager S and the Editors of Prevention Health
Books. The Doctor's Book of Food Remedies. Rodale
Books 1997.
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