Essential Amino Acids 

  Essential amino acids are the building blocks of proteins they play a major role in most of the functions and processes of the body.Some of these functions include formation of the structural framework of various parts of the body, keratin in skin, hair and nails, collagen and connective tissue. As hormones they regulate various physiological functions, play a contractile role in muscle tissue, perform immunological functions in  the formation of antibodies,as hemoglobin transport vital substances thoroughout the body and play a catalytic role as enzymes regulating biochemical reactions.

Proteins help to regulate the body's water balance,  maintain the internal pH, and form the structural basis of chromosones which pass on genetic material from parents to their children.The proteins that make up the body are not obtained directly from the diet as such, all dietary protein is broken down into amino acids, which the body then restructures in accordance with its own specific protein needs.

Without amino acids, vitamins and minerals  would not be able to be effecttive, so it is most important to have the correct levles of amino acids present.Deficiency of tyrosine may lead to an iron deficiency, if methionine and taurine are not present in sufficient amounts allergies and autoimmune disorders. Depression and neurological problems of the elderly may be as a result of low levels of tyrosine, trytopan, phenylaline and histidine.

Apart from the amino acids produced naturally by the liver, which form the bulk of amino acids used by the body, the remaining amino acids must be obtained from the diet, these amino acids are known as the twenty essential amino acids which are:

Trytophan, lysine, methionine, phenylalaine, threonine, valine, leucine and isoleucine, these essential amino acids must be obtained from the diet. The remaining amino acids which can be manufactured by the body provided the essential amino acids are obtained from the diet, these are termed non essential amino acids:

 Arginine, tyrosine, glycine, serine, glutamic acid, aspartic acid, taurine, cystine, histidine, proline and alanine. It's important to be aware of the fact that although they are termed non essential this does not imply not necessary, in fact they are most necessary and play important roles in many body functions.

What do these amino acids do, and where can I get them from?

The eight essential amino acids have many important functions:

Isoleucine  is needed for hemaglobin formation and to regulate blood sugar and energy levels.It is found in beef, chicken, chickpeas, eggs, fish, lentiles, rye, soy beans,almonds, milk, and pumpkin seeds. Factors which increase the demand for this amino acid are premature births, renal and liver disease, and for athletes.

A deficiency of isoleucine may be associated with poor growth, tremors, twitching of muscles and diabetes. Caution is needed if supplementing with this amino acid for overdosing may result in high ammonia levels and an hypoglycemic state. Ideally it is far better to obtain the amino acid from the diet.

Leucine stimulates insulin release, promotes wound healing, increases growth hormone production,regulates muscle protein synthesis, and lowers brain levels of serotonin and dopamine.

Leucine sources are brown rice, beans, meat, soy flour, whole wheat, fish, eggs, liver, chicken, corn almonds, and cashews. This amino amino acid is required in infants, during growth spurts such as puberty, renal and liver disease, and after surgery. A deficiency of leucine may cause or be associated with poor growth.  Overdosing with leucine may contribute to pellagra and increase ammonia levels in the body, therefore moderation is called for here.

Lysine is a building block for all proteins, it forms an important component of hormonal proteins, assists collagen formation and enzymes, aids in the production of antibodies, tissue repair, and carnitine synthesis.

Food sources of lysine are: fish, chicken, brewers yeast, cheese, eggs, mung bean sprouts, soy and lima beans, and red meat.A deficiency of lysine may be associated with anaemia, irritability, inability to concentrate, loss of weight, decreased growth, loss of bone calcium,fatigue, nausea, dizziness, infertility, poor immune function.Lysine is well known for its ability to prevent or overcome cold sore outbreaks, for best results combine the lysine with vitamin C and bioflavanoids. Another plus for lysine is that it lowers serum triglyceride levels.

Methionine is an essential amino acid which aids in the breakdown of fats  preventing the development of atherosclerosis . It is a good source of sulfur which inactivates free radicals, it helps to detoxify heavy metals, it is therefore a good idea to increase food sources of methionine as the levels of toxic substances increase ,it reduces histamine levels benefiting allergy sufferers, and is involved in the synthesis of choline.

Food sources of methionine include: Eggs, beans, garlic, onions, meat, fish,lentils, soybeans, seeds, sardines and yoghurt. A deficiency of methionine may be associated with atherosclerosis, poor immunity, loss of appetite ,and choline deficiency.

Phenylalanine is an essential amino acid, it is a precursor of tyrosine, which leads to the synthesis of dopamine, nor adrenalin, thyroxine and melanin. This amino acid is capable of elevating mood, decreasing pain, it forms a constituent of enkephalins which are naturally occurring opinoid compounds.

Food sources of phenylalanine include: soy beans, cottage cheese, fish, meat, nuts and lentils.

Threonine is an essential amino acid helping to maintain protein balance in the body. It plays an important role in the formation of collagen and elastin, is an essential precursor of glycine, and serine, aids lipotropic function helps to prevent fatty liver, and is an immuino stimulant aiding in the production of antibodies.

Food sources of threonine include, eggs, meat, milk, cheese and pork.

Tryptophan is an essential amino acid , it is a precursor of Vitamin B3, melatonin, and serotonin (5HT), in this way it acts as a mood stabilizer, assists sleep, and helps to control hyperactivity in children.

Food sources of tryptophan include: brown rice, soy protein, cottage chees, , meat, peanuts, pumpkin seeds,fish and sesame seeds.

Valine is an essential amino acid needed for tissue repair, muscle metabolism, and to maintain nitrogen balance in the body.

Food sources of valine include: soy flour,  fish, beef, lamb, chicken, almonds, chick peas, lima beans, mushrooms. grains, and dairy products.

Read more:Non essential amino acids 

References: Osiecki, Henry.B.Sc(Hons) Grad.DipNutr.and Dietics. Nutrients in Profile, Bioconcepts publishing Kelvin Grove Q.Australia 1990.

Balch,James.M.D. & Balch, Balch, Phyllis A Prescription for Nutritional Healing second edition, Avery Publishing Group, New York 1997.