Amino acids form the proteins that in turn, form muscle tissue. Without amino acids, all cellular development, respiration, and renewal would cease. There are just 22 amino acids, but without them all of the metabolic processes necessary to spark and sustain life would not be possible. Long chains of amino acids combine to form up to 55,000 different proteins, and each protein is used to produce the enzymes, neurotransmitters, and hormones that support normal growth and functioning of all bodily organs, including the heart, brain, liver, kidneys, and sex organs.

There are two types of amino acids: essential amino acids and nonessential amino acids. Essential amino acids cannot be manufactured in the body (you get them by eating foods that contain protein), and nonessential amino acids are manufactured within the body by combining two or more essential amino acids. However, adequate amounts of dietary protein are needed to form all 22 amino acids, if you don’t get enough protein your body won’t have the 9 essential amino acids it needs to make up the other 13 nonessential amino acids. Today’s Western diet is composed largely of processed foods, and often sadly lacking in quality protein, so just about everyone could benefit from some form of amino acid supplementation.

ESSENTIAL AMINO ACIDS

These 9 amino acids are essential amino acids, which are also referred to as indispensable, are the ones you must get through the foods you eat because your body can’t make them. These essential amino acids include: valine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and histidine. Your body doesn’t store amino acids, so it needs a regular daily supply of these essential building blocks.

 

  • Histadine:  Histidine is an amino acid that is used to develop and maintain healthy tissues in all parts of the body, particularly the myelin sheaths that coat nerve cells and ensure the transmission of messages from the brain to various parts of the body. Histidine levels in the body must be balanced to ensure good mental and physical health. Histidine is important to normal sexual functioning, because it gets converted into histamine, a chemical needed to stimulate sexual arousal.
  • Leucine:  Leucine is a branched-chain amino acid (BCAA), that is best known for its ability to increase endurance and help heal and repair muscle tissue. Leucine is the most effective BCAA for preventing muscle loss because it breaks down and is converted to glucose more quickly than the other two BCAA’s isoleucine and valine. Increased glucose supplies prevent the body’s cannibalization of muscle for energy during intense workouts. Leucine also increases production of growth hormones, and helps the body burn visceral fat, located in the deepest layers of the body.
  • Isoleucine:  Isoleucine is a branched-chain amino acid (BCAA), that is important to athletes because it boosts energy and helps the body recover from strenuous physical activity, while regulating blood sugar, to keep energy levels stable.
  • Lysine:  Lysine enhances athletic performance. Lysine, in combination with arginine, improves athletic performance by boosting growth hormones and helping muscles recover quicker. Lysine also promotes the formation and building of collagen, one of the most abundant proteins in our bodies. Collagen builds cartilage, bones, and connective tissues. Lysine limits bone loss, by helping your body readily absorb calcium and reducing the amounts of calcium excreted in urine. Lysine is also important for the immune system, as it is involved in the development of antibodies.
  • Methionine:  Methionine is lipotropic, or a chemical substance that helps the liver process fats (lipids), which is essential for the elimination of toxins from the body. Methionine produces cysteine and taurine, which help the body eliminate toxins, build strong, healthy tissues, and promote cardiovascular health. Methionine also produces creatine, which provides the energy muscles need to move, and boosts athletic performance during short, intense workouts. Methionine is essential for the formation of healthy collagen used to form skin, nails, and connective tissue, and helps reduce the level of inflammatory histamines in the body.
  • Phenylanine:  Phenylalanine is involved in the synthesis of neurotransmitters, especially dopamine, norepinephrine, and epinephrine. Phenylalanine also aids in the production of melatonin, which controls and regulates sleep and wake cycles. Phenylalanine is the direct precursor of tyrosine, which can then be converted into dopamine. Tyrosine helps with anxiety. Dopamine plays an important part in many different physiological processes such as in pain perception and the reward system of the brain. Phenylalanine crosses the blood-brain barrier and enters into the central nervous system, which is integral cognitive benefits, such as improved memory and enhanced alertness.
  • Threonine:  Threonine promotes growth by helping maintain the proper protein balance in the body. Threonine also supports cardiovascular, liver, central nervous, and immune system function. Threonine is needed to create glycine and serine, two amino acids that are necessary for the production of collagen, elastin, and muscle tissue, which keep connective tissues and muscles throughout the body strong and elastic. Threonine also combines with the amino acids aspartic acid and methionine to help the liver with lipotropic function, or the digestion of fats and fatty acids.
  • Tryptophan:  Tryptophan, the chemical precursor to serotonin, improves cognition, mood and sleep. Tryptophan improves both the time to fall asleep as well as the quality of sleep. Tryptophan is converted into serotonin in your body. Excess serotonin is then converted into melatonin. Melatonin is known as the ‘sleep hormone’ and helps to promote sleep. An increase in serotonin also reduces feelings of stress and anxiety, often a byproduct of the improved mood and better sleep. Tryptophan improves exercise performance through the serotonin system by enhancing neural drive and helping to enhance stamina. Tryptophan can also mediate appetite, via serotonin, and control weight.
  • Valine:  Valine is a branched-chain amino acid (BCAA) that works with the other two BCAAs, isoleucine and leucine, to promote growth, repair tissues, regulate blood sugar, and provide the body with energy. Valine helps prevent the breakdown of muscle by supplying the muscles with extra glucose for energy production during intense physical activity.

 

CONDITIONALLY ESSENTIAL AMINO ACIDS

Of the 11 nonessential amino acids, eight are called conditional amino acids. When you’re sick or under significant stress, or after an intense workout, your body may not be able to produce enough of these amino acids to meet your needs. The list of conditional amino acids includes arginine, glutamine, tyrosine, cysteine, glycine, proline, serine and ornithine. The remaining three — alanine, asparagine and aspartate — are nonessential.

 

  • Arginine:  Arginine is beneficial for the heart. In the body, arginine is converted into nitric oxide (NO). Nitric oxide is a powerful neurotransmitter that helps blood vessels relax and also improves circulation. Arginine also enhances physical performance, stamina and strength. It stimulates the production of certain hormones, especially growth hormones and insulin that help usher glucose into cells to be used for growth and energy output. Arginine helps the body process creatine, a natural substance that helps build muscle mass. It increases blood flow, bringing nutrients and oxygen to muscle and joint tissues. Arginine also improves immune function, as it has substantial free radical-scavenging abilities due to its effects on the enzyme called superoxide dismutase (SOD) as well as other antioxidant mechanisms. It also stimulates the immune system by increasing the output of T lymphocytes (T- cells) from the thymus gland.
  • Cysteine:  Cysteine, also called N- acetylcysteine, is a sulfur-based amino acid that is a building block for glutathione, a natural antioxidant enzyme produced in the body to fight free-radical activity. Without glutathione, the body’s immune system would be greatly compromised, and left with little defense against toxins and disease. Cysteine is found in beta-keratin, the main protein in nails, skin and hair. It helps maintain a healthy, youthful appearance by encouraging collagen production and skin elasticity. Its detoxifying effects may also help enhance the benefits of regular exercise by protecting the body from oxidative stress.
  • Glutamine:  Glutamine is the most abundant amino acid found in the human body and plays a vital role in the metabolic processes. Glutamine aids the immune system, provides fuel to many cells in the body, and is a necessary energy source for the body. Glutamine transports nitrogen to the muscles, which prevents muscle breakdown, and is useful for dieters and bodybuilders. Glutamine also promotes a healthy digestive tract by helping to balance acid/alkaline levels in the body. Glutamine is also a precursor of glutathione, the master antioxidant in the body.
  • Glycine:  Glycine prevents the breakdown of muscle by boosting the body’s levels of creatine, a compound that helps build muscle mass. Glycine is used in the body to maintain a healthy central nervous system by helping to construct normal DNA and RNA strands—the genetic material needed for proper cellular function and formation. Glycine is also essential for a healthy, normally functioning digestive system as it regulates the synthesis of the bile acid used to digest fats. Without glycine, the body would not be able to repair damaged tissues; the skin would become slack as it succumbed to UV rays, oxidation, and free radical damage, and wounds would never heal.
  • Proline:  Proline is needed for the production of collagen, cartilage and the maintenance of muscle tissue. It keeps muscles and joints flexible and helps reduce sagging and wrinkling that accompany UV exposure and normal aging of the skin. Proline helps the body break down proteins for use in creating healthy cells in the body. Proline is beneficial for endurance athletes, as it’s depletion will cause the body to cannibalize its muscle for energy.
  • Serine:  Serine is a non-essential amino acid derived from the amino acid glycine. It is important to overall good health, both physical and mental. Serine helps form the phospholipids needed to make every cell in your body. It is also involved in the function of RNA and DNA, fat and fatty acid metabolism, muscle formation, and the maintenance of a healthy immune system. Serine is also needed to produce tryptophan, an amino acid that is used to make serotonin, a mood-determining brain chemical. Serine helps produce immunoglobulins and antibodies for a strong immune system, and also aids in the absorption of creatine, a substance made from amino acids that helps build and maintain all the muscles in the body, including the heart.
  • Tyrosine:  Tyrosine is a nonessential amino acid the body makes from another amino acid called phenylalanine. It is an essential component for the production of several important brain chemicals called neurotransmitters, including epinephrine, norepinephrine, and dopamine. Neurotransmitters help nerve cells communicate and influence mood. Tyrosine also helps produce melanin, the pigment responsible for hair and skin color. It helps in the function of organs responsible for making and regulating hormones, including the adrenal, thyroid, and pituitary glands. It is involved in the structure of almost every protein in the body.

 

NON-ESSENTIAL AMINO ACIDS

Non-essential amino acids are synthesized in your body from other amino acids, glucose and fatty acids. Nonessential is a slightly misleading label because these amino acids actually fill essential roles, but since they’re synthesized by your body, they’re not an essential part of your diet.

  • Alanine:  Alanine, or L-alanine, is an amino acid that helps the body convert the simple sugar glucose into energy and eliminate excess toxins from the liver. Alanine has been shown to help protect cells from being damaged during intense aerobic activity, when the body cannibalizes muscle protein to help produce energy.

AMINO ACID DERIVATIVES

An amino acid derivative is a molecule that is generated using an amino acid as a starting point (precursor). In most cases, you can think of an amino acid derivative as the original amino acid plus or minus an extra chemical group.

  • Carnitine:  Carnitine, or L-Carnitine, helps the body turn fat into energy. It transports long-chain fatty acids into the mitochondria so they can be oxidized (“burned”) to produce energy. It also transports the toxic compounds generated out of this cellular organelle to prevent their accumulation. The body makes Carnitine in the liver and kidneys and stores it in the skeletal muscles, heart, brain, and sperm. Carnitine also acts as an antioxidant. Antioxidants fight harmful particles in the body known as free radicals, which damage cells and tamper with DNA. Antioxidants can neutralize free radicals and may reduce or help prevent some of the damage they cause. Carnitine also aids in weight loss by reducing fat mass, increasing muscle mass, and reducing fatigue.
  • Taurine:  Taurine is a byproduct of the amino acids cysteine and methionine. Taurine enhances physical performance, calms anxiety, and is essential for a healthy heart and brain. Taurine improves athletic performance and recovery, and is often used by endurance athletes and bodybuilders to relieve cramps, muscle soreness, and fatigue. When paired with branched chain amino acids (BCAAs), taurine reduces post-exercise muscle soreness. Taurine calms anxiety as it stimulates the release and formation of Gamma-aminobutyric acid (GABA) in the brain. GABA is the brain’s key calming neurotransmitter and is essential for feeling happy and relaxed. Low GABA levels can be brought on by stress, physical exertion, illness, injury, blood sugar imbalance, or gluten intolerance. Taurine has neuroprotective capabilities and can help protect against age-related mental decline, by increasing the level of brain-derived neurotrophic factor (BDNF). This protein acts like fertilizer in your brain, stimulating the growth of new brain cells. Taurine promotes the formation of new brain cells in the hippocampus, the part of the brain considered the “memory center.” Taurine also has antioxidant, anti-inflammatory, and antidepressant properties.