Amino Acids

• N-Acetyl Cysteine

Amino acids are the most important components of proteins. And proteins are essential to the health and function of every tissue in the human body. In fact, the word "protein" derives from the Greek "protos," meaning "first," a designation underscoring its pre-eminence.

Of the 29 amino acids none are interchangeable. Each one has a specific purpose and function of its own, and we need each one for overall superior mental and physical health.

There are three classifications of Amino Acids:

1. Essential amino acids must be included in your diet because your body can't make them on its own. If you don't ingest them, you will not be experiencing optimal health and may have a disease caused by that deficiency.
2. Non-essential amino acids can be manufactured by your body, under normal conditions so you don't have to ingest each of these.
3. Conditionally-essential amino acids become essential if your system is stressed, out of balance, or diseased, and you must get them from food or supplements.

Essential amino acids are considered to be ones that we must ingest, while non-essential has historically been believed to be produced inside our bodies. In other words, it has been felt that we do not need to supplement our diet with non-essential amino acids. This thinking does not hold up well in the light of actual, clinical experience. When we are suffering from a moderate to severe chronic illness, we lose the ability to manufacture enough non-essential amino acids, and thus require supplementation. Problems with digestion will also necessitate supplementation of "non-essential" amino acids. Most people have been told that if you eat a balanced diet, you'll get all the amino acids you need. That simply is not true if you are significantly out of balance. For example, if your amino acid testing reveals a significantly low Tryptophan, you will have to eat several turkeys a day or drink gallons of milk to get enough Tryptophan from a natural source. Recent research has led to a third category within this classification system, namely, "Conditionally Essential." These amino acids are normally non-essential, but become essential during times of physiological stress.

Acetyl L-Carnitine

is a naturally occurring nutrient in the body. Acetyl-L-carnitine (ALC) transports fats into the mitochondria. ALC's benefits may include brain protection from signs of aging, improved memory with long-term use, increased attention and vitality, and protection and treatment of senile dementia. Recent studies have confirmed that ALC can reduce both lipid peroxidation and lipofuscin concentration in brain cells. Some research has suggested that ALC supplementation may be useful in the management of Alzheimer's and Parkinson's disease.

Arginine

is a non-essential amino acid that the body can synthesize in the liver, however in times of stress or trauma arginine becomes an essential amino acid. Arginine boosts nitric oxide production, making it potentially useful in the treatment of congestive heart failure, intermittent claudication, angina, impotence, and sexual dysfunction in women. Arginine relaxes blood vessels, keeps arteries flexible, and seems to act as a natural anticoagulant by reducing the "stickiness" of platelets. Preliminary evidence suggests that arginine may help to regulate cholesterol levels. Together, these benefits suggest that arginine may help to reduce the risk of heart disease, heart attack, and stroke. Arginine is also vital for the production of protein and the secretion of the hormones glucagon and insulin. It also stimulates the pituitary gland to release growth hormone. Arginine can also help to increase sperm production, boost the immune system, and aid wound and burn healing.

Branched Chain Amino Acids (BCAA's) Leucine/Isoleucine/Valine

are used by the body to manufacture proteins. Muscles have a high content of BCAA's. Adequate amounts of BCAA's are usually obtained from the diet; however, injury can increase the body's need for BCAA's in order to repair damage. BCAA's are often used for their muscle-building properties; however, the majority of evidence obtained from clinical studies suggests that they do not improve performance, reduce fatigue, or increase the body's muscle/fat ratio. Results of a 1999 study suggest that BCAA's might improve the symptoms of tardive dyskinesia, a movement disorder caused by long-term use of antipsychotic drugs. Other studies have found that supplementary BCAA's may reduce the symptoms of Lou Gehrig's disease (amyotrophic lateral sclerosis (ALS)), and improve the appetite of cancer patients.

Cysteine, N-acetyl cysteine (NAC)

is a non-essential amino acid that can be manufactured in the liver. N-acetyl cysteine (NAC) is a modified form of cysteine. NAC helps the body make the antioxidant enzyme glutathione. Cysteine may help to diminish the effects of aging, protect against heart disease and cancer, boost the immune system, promote metabolism of fats and production of muscle tissue, aid healing after surgery, promote hair growth, and prevent hair loss. It is also known to work synergistically with vitamin E and selenium as an antioxidant, protecting against the damaging effects of radiation, acetaldehyde, acrolein in tobacco smoke, alcohol and environmental pollutants. Several studies have found that NAC is beneficial to patients with chronic bronchitis and angina; there is also preliminary evidence to suggest that it may help to prevent colon cancer Some experts believe that NAC increases the efficacy of chemotherapy drugs and helps to alleviate their side effects, however there is little clinical evidence to support this. Very high doses of NAC are given to patients in hospital to treat acetaminophen poisoning.

Gamma Aminobutyric Acid (GABA)

is a non-essential amino acid that functions as the most prevalent inhibitory neurotransmitter in the central nervous system (CNS). GABA is found in large amounts in the hypothalamus, this implies that the amino acid has a fundamental role in hypothalamic-pituitary function, and thus neuroendocrine metabolism. The hypothalamus is a region of the brain, which regulates the autonomous functions, such as sleep, body temperature and the activity of the pituitary gland. The pituitary is an endocrine gland that affects all hormonal functions of the body. It is the pituitary gland that secretes the much talked about growth hormone, however GABA is an excellent substitute for growth hormone and several clinical studies have found that ingestion of GABA, especially after exercise, stimulates the pituitary to secrete growth hormone. Because of its inhibitory effects upon the CNS, supplemental GABA can be useful for aiding relaxation. GABA can help to decrease epileptic seizures and muscle spasms by inhibiting message transmission in neurons. This helps control nerve cells from firing too fast, which would overload the system. As GABA stimulates the secretion of growth hormone from the pituitary, it can help to increase lean body mass. GABA also lowers blood pressure, helps control hypoglycemia, prevents anxiety, and promotes sleep.

Glutamic Acid (Glutamate)

is a non-essential amino acid that the body uses to build proteins. The fluid produced by the prostate gland contains significant amounts of glutamic acid. This has led scientists to believe that glutamic acid may play a role in the normal functioning of the prostate. One clinical study found that supplementary glutamic acid significantly improved the symptoms of benign prostatic hyperplasia (BPH). There is some evidence to suggest that glutamic acid may have protective effects on heart muscle. Results of one study revealed that intravenous injections of glutamic acid (as monosodium glutamate) increased exercise tolerance and heart function in people with stable angina pectoris. However, whether a similar effect would be seen with oral glutamic acid is uncertain.

Glutamine

is the most abundant amino acid in muscles and blood. Glutamine provides fuel for various cells of the immune system and is a critical component in wound repair. The body can make glutamine, but may not make enough when the body is under stress. Preliminary evidence suggests that glutamine might help prevent infections in people who are over-stressed and athletes who are overtrained - and thus immunosuppressed. Glutamine may also be useful as a nutritional supplement for people undergoing recovery from illness. Some scientists have also suggested that glutamine could be useful as a treatment for food allergies. This speculation is based on a theory called "leaky gut syndrome," where proteins leak through the wall of the digestive tract and enter the blood, causing allergic reactions. There is some evidence to support this theory as several studies have suggested that glutamine supplements might reduce leakage through the intestinal walls. Because of this glutamine supplements have been suggested for people with other digestive problems, such as irritable bowel syndrome, Crohn's disease, and ulcerative colitis. However, there have also been trials that have found that glutamine supplements were of no benefit to these people. Glutamine may be of benefit to patients with HIV as it has been shown to increase levels of glutathione, which interferes with viral activation, as well as significantly increasing lean body mass. Based on glutamine's role in muscle, the amino acid may be useful for athletes experiencing overtraining syndrome.

Glutathione

is a tripeptide composed of the three amino acids - glycine, glutamic acid (glutamate), and cysteine. Glutathione has been called the "master antioxidant," in addition to its own potent antioxidant powers glutathione helps to recycle other antioxidants such as vitamins C and E. Thus, glutathione can help to protect against cancer and other diseases caused by oxidative damage. Glutathione also plays an important role in the regulation of immune cells, and is a potent detoxifying agent. Low levels of glutathione have been associated with hepatic dysfunction, immune dysfunction, cardiac disease, and premature aging. It is also important in DNA synthesis and repair, protein and prostaglandin synthesis, and amino acid transport. Several studies have shown that glutathione has antiviral properties. Research has shown that glutathione inhibits activation of the HIV virus, therefore it may be beneficial to people with HIV and AIDS.

Glycine

is a non essential amino acid that is important in the control of gluconeogenesis - the manufacture of glucose from glycogen in the liver. Glycine is also one of the few amino acids that can spare glucose for energy by improving glycogen storage. Therefore, inappropriate blood glucose control may be managed by increased glycine intake. Glycine is also known to serve as a source of nitrogen for the manufacture of many other amino acids and is useful in the synthesis of hemoglobin, glutathione, DNA, and RNA. Glycine is required by the body for the maintenance of the central nervous system, and the synthesis of the porphyrin core of hemoglobin. It also enhances the activity of neurotransmitters (chemical messengers) in the brain that are important for memory and cognition. The amino acid is also required for the prostate gland to function correctly.

Several studies have found that high doses of glycine, in combination with standard therapy, may be useful in the treatment of schizophrenia. Glycine may also be useful in treating stroke victims. One study found that relatively small doses of the amino acid were able to significantly reduce the damage to brain cells that occurs after a stroke. However, some studies have found evidence to suggest that high doses of glycine could actually increase stroke damage. Thus, the benefits of glycine in limiting stroke damage remain inconclusive.

Animal studies have found that dietary glycine may protect against chemical damage to the liver and kidneys, however there is no human data to back up these findings. Finally, there is some evidence to suggest that topically applied glycine may aid in wound healing. Results of at least two studies have shown that supplementary glycine taken in combination with equal amounts of the amino acids, alanine and glutamic acid, significantly improves the symptoms of benign prostatic hyperplasia (BPH).

Histidine

is occasionally referred to as a semi-essential amino acid. This means that the body can usually produce adequate amounts of histidine; however in certain circumstances, such as periods of rapid growth, the body cannot supply enough to meet demand.

The body uses histidine to produce histamine, a substance that plays a central role in allergic reactions and other functions of the immune system. Histidine also helps to chelate trace minerals and copper, thus aiding their removal from the body. People with rheumatoid arthritis may have low blood levels of histidine. This discovery led to speculation that histidine supplements may be of benefit to patients with rheumatoid arthritis. However, as of yet no clinical studies have been able to find any evidence to support these theories.

Homocysteine

is a sulfur-containing amino acid involved in methionine metabolism. It has become evident during the past few years that homocysteine (Hcy) is a major independent risk factor for cardiovascular disease - joining the ranks of dyslipidemia, hypertension and smoking. An elevated level of Hcy in the blood increases the risk of atherosclerosis, and consequently heart attacks and strokes. Hcy causes direct damage to the lining of blood vessels, weakening them and opening them to the accumulation of plaque. There is also some evidence to suggest that Hcy may be a thrombogenic agent that triggers the formation of blood clots. Interestingly, it was recognized more than 30 years ago that individuals with an inborn error of metabolism, cystathionine betasynthase deficiency, had a 50 to 100-fold elevation in circulating Hcy and excreted large amounts of Hcy in the urine. Premature vascular disease and implicated subclinical deficiencies of B-vitamins are contributing factors. It was estimated that a 5 umol/L increase in serum Hcy is associated with 60 to 80% increased risk of coronary artery disease (CAD). Homocysteine has also been linked to Alzheimer's disease, Parkinson's disease, and osteoporosis.

Lysine

is an essential amino acid that helps to regulate the pineal gland, mammary glands, and ovaries. It is important for growth and bone development, promotes calcium absorption, maintains nitrogen balances, aids in the production of antibodies, hormones, and collagen, and helps to build muscle tissue. Several studies have found that regular use of lysine supplements might be able to reduce the frequency and intensity of herpes virus flare-ups. Both cold sores and genital herpes are caused by the herpes simplex virus, after the initial infection with herpes the virus hides in nerves cells and causes flare-ups of the disease at times of stress, e.g. when the body is immuno-compromised. In vitro studies suggest that lysine combats the herpes virus by blocking the amino acid arginine, which the herpes virus requires in order to replicate.

Methionine

is an essential amino acid that is required for the absorption, transportation, and bioavailability of zinc and selenium in the body. Methionine also facilitates the breakdown of fats and prevents accumulation of fat in the liver and arteries.

Methionine

appears to prevent bacteria from adhering to the wall of the bladder; this property of methionine has led to it being suggested as a treatment for recurrent urinary tract infections (UTI's). One trial has found evidence to support this claim, yet the use of methionine in preventing UTI's has not been confirmed. Methionine has been shown to be effective in the prevention of acetaminophen toxicity, and some experts have suggested selling acetaminophen in combination with the amino acid to prevent acetaminophen poisoning. However, there has been some speculation that chronic use of methionine can increase homocysteine levels.

Phenylalanine

is an essential amino acid that once inside the body is converted into the amino acid tyrosine, which is then converted into the neurotransmitters L-dopa, norepinephrine, and epinephrine. Phenylalanine governs the release of the hormone cholecystokinin (CCK) that signals the brain to feel satisfied after eating.

Phenylalanine

is used to treat a variety of medical problems. Because some antidepressants work by raising norepinephrine levels phenylalanine has been used to treat depression, with varying degrees of success. D-phenylalanine has been suggested as a treatment for chronic pain caused by rheumatoid arthritis, muscle pain, and osteoarthritis, as It blocks enkephalinase, an enzyme that may act to increase pain levels in the body. There is some evidence to support the use of phenylalanine to alleviate chronic pain, although it has not been clinically proven. Some studies have suggested that the various forms of phenylalanine may be useful as a treatment for vitiligo (a disease characterized by abnormal white blotches of skin due to loss of pigmentation), when used in combination with UV light therapy.

SAMe (S-adenosyl-L-methionine, S-adenosylmethionine)

is a compound made from methionine, a sulfur-containing amino acid, and adenosine triphosphate (ATP) - the body's "energy" molecule. SAMe was discovered by an Italian biochemist in 1952, and was first studied as a treatment for depression; during these studies it was found that SAMe also helped to relieve the symptoms of arthritis. At present, SAMe is classed, along with glucosamine and chondroitin, as a potential "chondroprotective" agent, i.e. a substance that not only relieves the symptoms of arthritis but also helps to slow its progression. However, this use of SAMe is yet to be clinically proven. The body usually produces adequate amounts of SAMe, thus there is no dietary requirement. However, methionine, folate, or vitamin B12 deficiencies can reduce SAMe levels and as it is not found in significant quantities in foods, it must be obtained from a supplement.

Serine

is a non-essential amino acid needed for the metabolism of fats and fatty acids, muscle growth, and to maintain a healthy immune system - as it aids the production of immunoglobulins and antibodies. It also plays an important role in the manufacture of cell membranes, and the synthesis of both muscle tissue and the sheath that surrounds nerve cells. When necessary the body can synthesize serine from the amino acid glycine.

Phosphatidylserine (PS)

is a serine compound made by the body. Supplemental PS is widely used in Italy, Scandinavia, and other parts of Europe to treat various forms of age related dementia as well as normal age related memory loss.

PS supplements increase the cerebral cortex's output of the neurotransmitter acetylcholine, which is associated with thought, reasoning, and concentration. PS stimulates the synthesis and release of dopamine. PS also appears to be associated with the brain's response to stress. One clinical study found that the stress response of healthy men who had been exposed to exercise induced stress was lower in those who had taken PS. Stress response was determined by measuring blood ACTH levels, ACTH is a hormone secreted by the pituitary gland, which in turn promotes the adrenal glands to secrete the stress hormone cortisol. PS is primarily used to treat dementia (both Alzheimer's disease and non-Alzheimer's dementia) as well as normal age-related memory loss.

Taurine

is a non-essential amino acid that protects cell membranes from damage, and enhances the immune system by stimulating the release of interleukin-1 in macrophages, and increasing the phagocytic and bactericidal activity of neutrophils. It also helps to detoxify toxic substances such as retinoids and environmental toxins. Several studies have found that taurine might be useful in the treatment of congestive heart failure (CHF), and at least one study has found that it may also be useful for acute viral hepatitis. Taurine also increases levels of the neurotransmitter acetylcholine levels and helps to regulate the nervous system.

Threonine

is an essential amino acid. As with all amino acids, threonine is important for the formation of proteins, however it is especially required for the production of tooth enamel, collagen, and elastin. Threonine helps to metabolize fat and prevents a build-up of fat developing in the liver; it is also useful for intestinal disorders, and indigestion.Threonine can help to stabilize the blood sugar as it can be converted into glucose in the liver by gluconeogenesis. People who have been burned, wounded, or undergone surgery have higher than normal levels of threonine in their urine. This indicates that the amino acid is released from the tissues following trauma. Recent research indicates that increasing threonine intake during these periods may aid the recovery process. Several study findings have suggested that threonine might be able to decrease the muscle spasticity that often occurs with MS, however this use of threonine has not been clinically proven.

Tryptophan

is an essential amino acid, it is required for the production of vitamin B3 (niacin), which is vital for the brain to manufacture serotonin. Tryptophan also boosts the release of growth hormones, and helps to suppress the appetite.

5 Hydroxytryptophan (5-HTP)

is used by the body to manufacture the neurotransmitter serotonin. Due to its effects upon serotonin levels, 5HT is often used as an antidepressant.5HT's use antidepressant effects are well-documented. Some studies have also suggested that the supplement may help to reduce the frequency and severity of migraines, however this benefit of 5HT has not been clinically proven. Recent findings have also indicated that 5HT may help to relieve the symptoms of fibromyalgia.

Trimethylglycine (TMG, Betaine)

is a non-essential amino acid that assists in methylation and may help protect cellular DNA from mutation. Trimethylglycine helps to keep the liver healthy by assisting the detoxification process, and animal studies suggest that the compound's methyl group-donating properties may help to protect the liver from chemical damage. Trimethylglycine aids in the conversion of homocysteine to methionine, and thus helps to lower levels of the amino acid homocysteine, high levels of which have been linked to an increased risk of heart disease, heart attack, stroke, Alzheimer's disease, Parkinson's disease, and osteoporosis.

Tyrosine

is a non-essential amino acid. It is a precursor for the neurotransmitters L-dopa, dopamine, norepinephrine, and epinephrine. Due to its effect on neurotransmitters, it is thought that tyrosine may benefit people with Parkinson's disease, dementia, depression, and other mood disorders. A study of US marines found that the amino acid helps to increase alertness in people suffering from sleep deprivation. Skin cells use tyrosine to form melanin, the pigment that protects against the skin from the damaging effects of ultraviolet light. Thyroid hormones, which play many important roles throughout the body, also contain tyrosine as part of their structure. In fact, tyrosine is used to produce the hormone thyroxin, which is important in the regulation of growth and metabolism, and is required for healthy skin and the maintenance of mental health. Finally, tyrosine may be of benefit to people who suffer from PKU.