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:Amino-Acids:
Sources: Free
range eggs are one of the best amino acid sources. Predigested proteins
are another excellent source, including One Step, Medipro, Hydrolyzed
Lactalbumin and Night-Lite (hydrolyzed collagen). Free form amino
acids are also available individually and in combinations for
specific therapeutic purposes, including neurotransmitter repletion.
Introduction
A protein can be defined as any substance which is made of amino
acids in peptide linkage. The word "protein" comes from
the Greek protos, "first," deservedly enough, as it is
the basic constituent of all living cells. Protos may also be the
root of the name of Proteus, a mythological figure who could change
form; appropriately, food protein changes form to become human substance
after being eaten.
Protein makes up three-fourths of the dry weight of most body cells.
Proteins are also involved in the biochemical structure of hormones,
enzymes, nutrient carriers, antibodies and many other substances
and functions essential to life.
Simple proteins made up of only a few amino acids are called peptides.
One should note that the word peptide comes from the Greek peptos,
"cooked," a rather poetic way of referring to digestion.
Peptides are often no more than digested proteins. Many peptides
are absorbed directly into the bloodstream after eating. New roles
for these very small proteins are being discovered almost daily,
it seems. For example, many peptides work as neurotransmitters and
as natural pain-relieving substances in the brain.
Scientists now know that protein as peptides can be absorbed immediately,
without digestion, into the bloodstream. However, the majority of
proteins are broken down into amino acids before absorption. It
is these amino acids that are the primary building blocks of human
life.
What Is an Amino Acid?
"Protein" is a well-recognized term, while the term "amino
acid" can be confusing. Amino acids are made up of a weakly
acid molecule group in conjunction with a strongly basic amino molecule
group. The mild basicity or acidity of amino acids is too minimal
to affect acid-base balance in the body, which is preserved by multitudes
of protective buffer systems. Thus we hope the misnomer, "amino
acid," will cease to confuse our readers.
Amino acids can be thought of as useful ammoniated vinegars. Glycine,
for example, has a more correct chemical name: alpha aminoacetic
acid. Since "amino" also means ammonia and acetic acid
is vinegar, we can call this amino acid "ammoniated vinegar."
This basic structure found in glycine is common to all amino acids.
Smelling salts are usually ammonium carbonate, which can restore
sensibility to people who have become faint. Vinegar, when added
to salads and other foods, makes the taste of food more palatable.
Similarly, some amino acids improve flavor or stimulate the mind.
They also can control depression or produce sleep. Eight of the
amino acids perform functions indispensable if the body is to stay
alive; they are termed "essential" and must be consumed
daily by everyone.
When acid or "vinegar" portions are removed from the amino
acids, the basic amines become messengers in the nervous system.
When the amine or ammonium portions are removed, the remaining "acid"
can be used for fuel, detoxification, or in many processes throughout
the body. The amino acids play innumerable roles in human health
and disease.
Essential Amino Acids
The necessity for protein and amino acids in the diet becomes cruelly
evident during great famines. Children suffering from kwashiorkor
(protein-calorie malnutrition)-with their grossly protruding abdomens,
atrophied muscle mass and mental retardation-vividly demonstrate
the essential nature of proteins and amino acids.
Minimum protein requirements for a healthy adult represent the sum
of the requirements for each of the eight essential amino acids,
plus sufficient utilizable nitrogen to maintain overall synthesis
of nitrogen-containing molecules. Nitrogen is lost in urine, feces,
skin, hair, nails, semen and menstrual discharge. Although there
are considerable problems in determining a minimum protein requirement,
it seems to be on the order of 0.3 to 0.4 gram of protein per kilo
(2.2 pounds) of body weight per day or about 30 to 40 grams for
the average adult male. This assumes a majority of the protein consumed
is high-quality protein and contains all or most of the essential
amino acids. The current recommended dietary allowance (RDA) is
44 to 56 grams per day. In America even vegetarian diets contain
80 to 100 grams of protein per day. However, the RDA is far from
optimal and is useful only as a minimum requirement.
The World Health Organization suggests that a newborn infant needs
dietary protein that contains 37 percent of its weight in the form
of essential amino acids, whereas for adults the figure is less
than half that, or about 15 percent.
People often do not realize their need for amino acids, because
they are not aware of how busy the human body is. Every second the
bone marrow makes 2.5 million red cells. Every four days most of
the lining of the gastrointestinal tract and the blood platelets
are replaced. Most of the white cells are replaced in ten days.
A person has the equivalent of new skin in twenty-four days and
bone collagen in thirty years. All this continuous repair work requires
amino acids.
The fist of the essential amino acids was begun by scientists in
the early 1900s. The main essential amino acids are now known to
be lysine, leucine, isoleucine, methionine, phenylalanine, threonine,
tryptophan and valine. A person would begin to die without ingesting
these amino acids daily, although the gut flora (bacteria) provide
small quantities of each of them. This actual continuous low level
of synthesis is essential; otherwise, symptoms of their absence
would be noticed often throughout the day.
Histidine and taurine are also essential amino acids for early growth
and development in premature infants and possibly for all neonates.
Preterm babies are also known to require cysteine, because the fetal
liver cannot convert methionine to cysteine.
Determination of the ideal intake of these amino acids is more difficult
than determination of the minimum daily requirement.
There are many other amino acids besides the essential ones that
the human body normally manufactures. These nonessential amino acids
may become essential to a particular individual through an inborn
error of metabolism. If an enzyme, necessary for the manufacture
of a particular amino acid by the body is absent, that amino acid
becomes an essential requirement of the diet. Nonessential amino
acids can also become essential during disease or stress when there
is either increased need and/or increased breakdown of them.
Many other amino acids occur in man in very small amounts; as yet
little is known about these. Furthermore, peptides (made up of two
or more amino acids) are also thought to be essential dietary constituents
that the body cannot make, but these peptides are not well understood.
In the future the list of essential and nonessential amino acids
may well be expanded.
Amino acid requirements are vastly increased by disease and by inborn
metabolic errors. Virtually all stress states require more amino
acids, some more than others do; distinguishing the source of the
increased amino acid requirements is often difficult. Burn patients
require more amino acids because of oozing wounds, while one type
of schizophrenic may have a recently expressed inborn error of metabolism
which dictates the need for less wheat gluten or serine Certain
cancers can be starved by withholding their "favorite' amino
acids. For example, melanomas consume excessive phenylalanine and
tyrosine; reducing these two amino acids in a cancer patient's diet
can slow tumor growth. The understanding and manipulation of required
amino acids in the diet is essential in maintaining health and controlling
disease.
Metabolism of Amino Acids as an Energy Source
The body breaks down excess amino acids essentially into either
fat or sugar to obtain energy. The amino acids which are transferred
into sugar are called glycogenic. The amino acids which are broken
down into fat are called ketogenic. All amino acids are valuable
energy sources.
Inborn Errors of Metabolism: Genetic Diseases
Many important clues about amino acid metabolism come from studies
of patients with inborn errors, as they are called. All of the amino
acids discussed in this book are involved in biochemical pathways
which can malfunction due to genetic disease. These inborn metabolic
errors teach about the toxicity of amino acids (which often causes
convulsions) and can occur when blood levels are increased five
to twenty times above normal. Conversely, other inborn errors can
cause deficiency symptoms. An understanding of genetic metabolic
errors is revealing the secrets of nutrient interactions among the
amino acids. Such studies reveal the basis for mega amino acid therapy,
and help explain the reasons why some individuals need 3 grams of
tryptophan daily whereas others need an extra gram of phenylalanine
daily.
Metabolism within the Brain
The most exciting area of amino acid research is the study of brain
metabolism. Communication within the brain and between the brain
and the rest of the nervous system occurs through chemical "languages,"
called neurotransmitters. There are about fifty such languages;
the amino acids, either as precursors, neurotransmitters or peptides
account for the majority of them.
The central nervous system is almost completely regulated by amino
acids and peptides. The brain's amino acids are now being recognized
for their importance, and amino acid therapies are revolutionizing
the treatment of psychiatric disease. In each chapter, we describe
a particular amino acid's therapeutic potential in psychiatry and
the regulation of brain function.
Amino Acids as Precursors
Amino acids are present and important throughout the body. For example,
muscle is very high in protein and amino acids. The heart muscle
and other organs derive their structure and function primarily from
amino acids. When the brain and other organs such as muscles, "talk"
to each other, amino acid-related neurotransmitters are again the
primary language. Throughout the body, the amino acids have important
functions themselves and as precursors for the manufacture of other
important substances. This is the reason that they have so much
potential value in medicine and surgery.
Precursor Functions of Some Amino Acids
Arginine
Spermine, Spermidine, Putrescine
Aspartic acid
Pyrimidines
Glutamic acid
Glutathione
Glycine
,Purines, Glutathione, Creatine, Phosphocreatine, Tetrapyrroles
Histidine
Histamine,Erothioneine
Lysine
Cadaverine, Carnitine, Amino-caproic acid
Ornithine
Polyamines
Methionine
Cysteine, Taurine
Serine
Sphingosine, Phosphoserine
Tyrosine
Epinephrine, Norepinephrine, Melanin, Thyroxine, Mescaline, Tyramine,
Morphine (bacteria), Codeine (bacteria), Papaverine (bacteria)
Tryptophan
Nicotinic acid, Serotonin, Kynurenic acid, Indole, Skatole, Indoleacetic
acid
Vitamin - Amino Acid Interactions
Amino acids and vitamins interact in interesting and important ways.
Pyridoxine, or vitamin B6, is the most important vitamin for amino
acid metabolism because it is the cofactor for the important enzymes
called transaminases, which metabolize amino acids. Riboflavin,
B2 and niacin, B3 are the next most important vitamins in amino
acid metabolism. An example of amino acid-vitamin interactions is
the relationship between tryptophan and niacin. Niacin is not really
a vitamin, but is actually made by the body from tryptophan. Thus,
supplemental niacin can spare tryptophan to serve other purposes
within the body.
It is worth noting that unlike the pure carbohydrate structure of
vitamin C, the B vitamins all contain nitrogen (amino group). They
are also acids. In some ways the B vitamins are amino acids, but
they are not incorporated into proteins.
Sources of the Essential Amino Acids
Both animal and plant proteins contain the known essential amino
acids. The removal of even one essential amino acid from the diet
leads rather rapidly to a lower level of protein synthesis in the
body and eventually to death. In general, protein from animal sources
is of greater nutritional value because animal proteins are complete
and contain all of the essential amino acids, plus the nonessential
ones.
The extent to which a food's amino acid pattern matches that which
the body can use is expressed in the "biological value"
of that food. The net protein utilization (NPU) reflects the biological
value and the digestibility of a protein-in other words, how much
of the protein a person eats is finally available to his body. No
food corresponds exactly with the body's required amino acid pattern,
but the amino acids in eggs come closest. Therefore, other proteins'
NPUs can be rated in relation to the marvelous egg.
Green vegetables and fruits are generally not considered because
of their negligible protein content. The essential amino acids most
commonly lacking in plants are lysine, tryptophan and methionine.
All cereals are deficient in lysine; corn and rice are also low
in tryptophan and threonine. Soybeans and oils are low in methionine.
Legumes are low in methionine and tryptophan; peanuts are deficient
in methionine and lysine. Poor quality meats seem to have higher
concentrations of less essential and sometimes even toxic amino
acids, such as serine and proline. Fermented foods, fungi and other
sources of protein are being investigated from the amino acid profile
point of view.
We believe the value shown for tryptophan is too low and the value
shown for lysine is too high. The FDA has considered regulating
the amino acid patterns of protein sources to insure proper quality
of diet. (Kirschmann and Dunne, 1984).
Another criterion for determining amino acid value is to calculate
the percent of usable protein; that is, the proportion of usable
protein in relation to the total weight of the food. Meats consist
of 20 to 30 percent usable protein, ranging from lamb at the bottom
to turkey at the top. Soybean flour is 40 percent protein; most
cheeses 30 to 35 percent protein; many nuts and seeds between 20
and 30 percent; and peas, lentils and dried beans between 20 and
25 percent. How much is usable amino acids is not known. Whole grains
contain a fairly small quantity of protein (12 percent); but so
do milk (4 percent) and eggs (13 percent). Thus, in evaluating the
value of a protein source, both quality and quantity must be considered.
Each chapter in our book provides this information about a particular
amino acid, enabling laypeople and dieticians to make sophisticated
dietary choices to promote health and alleviate disease.
Amino Acid Supplements
Amino acids are used in many different forms; some are free forms
or undigested forms. We will devote our time here with only the
free or individual forms, which are generally well absorbed throughout
the body and brain. All the amino acids can enter the brain; some
enter more easily than others do. Phenylalanine enters the most
easily, followed by leucine, tyrosine, isoleucine, methionine, tryptophan,
histidine, arginine, valine, lysine, threonine, serine, alanine,
citrulline, proline, glutamic acid and aspartic acid respectively.
The essential amino acids in general are better absorbed into the
brain than the nonessential.
Amino acids could possibly be better absorbed if they were taken
in the forms of di- and tri-peptides. In hospital settings, hydrolysates
or peptides are often more useful than free form amino acids. For
most physicians, nutritionists, and laypeople, use of the individual
L form amino acid supplement is best. However, for methionine and
phenylalanine, the DL form is better. D (right) and L (left) simply
refer to the direction of light rotation by the molecules of the
amino acid. The D forms may actually have to be converted by the
body to the L forms before being used. Variant or keto forms of
individual amino acids also have potential as supplemental substances.
Toxicity of amino acids often occurs only at doses 50 to 500 times
the therapeutic dose range.
Nutrient-Metabolic Basis of Disease
The study of amino acids is making a significant contribution to
the understanding of diseases. Nutritional assessment without measuring
plasma amino acids is incomplete, and marginal deficiencies of amino
acids are significant. We have begun to outline amino acid patterns
and deficiencies found in many diseases. Amino acid profiles contribute
to the more general concept of metabolic typing.
We have developed amino acid therapies that arrest herpes, improve
memory, raise depression, relieve arthritis and stress, prevent
aging and heart disease, control allergies and improve sleep, arrest
alcoholism, restore hair growth and alleviate many other conditions.
The study of amino acids is particularly relevant to all disease,
because the body normally uses amino acids to promote health and
fight disease. For example, during infection, plasma phenylalanine
levels increase significantly. By using amino acid therapies, we
are using the body's natural medicines. This has allowed us to state
two important principles of medicine:
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Imitatio
Corporis (Imitation of the Body): In the practice
of medicine, it is wise to imitate the body's natural healing
mechanisms. For example, when we can't sleep, we need to imitate
the body's usual biochemical mechanism of falling asleep, and
to give more of the dietary substances which the body normally
uses to put itself to sleep. Every nutrient has at least one therapeutic
use in the treatment of disease. Respect for God's mysterious
harmonies is the foundation of good health and of a "physical
morality."
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Pfeiffer's
Law: If a drug can be found to do the job of medical
healing, a nutrient can be found to do the same job. When we understand
how a drug works, we can imitate its action with one of the nutrients.
For example; antidepressants usually enhanceflav effect of serotonin
and epinephrines. We now know that if we give the amino acids
tryptophan or tyrosine, the body can synthesize these neurotransmitters,
thereby achieving the same effect and imitating or adding to the
net effect of these drugs. Nutrients have fewer, milder side effects,
and the challenge of the future is to replace or sometimes combine
drugs with the natural healers called nutrients.
At present, less than 20 percent
of the current drugs administered by a physician are effective (Klevax,
1984). All the healers a physician needs are in the body, there for
the harvesting by future generations of physicians and scientists.
Amino acids are an example of this harvest.
Indeed, the proof documenting the need for individual amino acid therapy
comes from the study of drugs. Many drugs affect certain amino acid
levels. Anticonvulsants, for example, seem to elevate the inhibitory
neurotransmitters. Taurine and glycine are increased while glutamic
acid and aspartic acid are reduced. Amino acid profiles often reflect
a drug's mechanism of efficacy. We are learning to replace drugs for
many difficult medical conditions with amino acids and are finding
good results and fewer side effects.
The rabbi doctor Maimonides wrote a thousand years ago, "The
knowledge of nutrition is the most helpful thing in the field of medicine
because of the constant need for food during health as well as illness."
Because of their fundamental contributions to body constituents and
biochemical functioning, amino acids, particularly the essential ones,
may prove even more valuable in the treatment of human disease than
minerals, fats or carbohydrates. Amino acids are indeed on the new
frontier in medicine. Our clinical experience described in case histories
rich with interesting reports of the benefits of amino acid therapy
document this belief.
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