Lesson 22: Amino Acids

Lesson 22: Amino Acids

Amino Acid

Amino Acids & Essential Amino Acids :

Amino acids are organic compounds composed of nitrogen, carbon, hydrogen and oxygen, along with a variable side chain group. Your body needs 20 different amino acids to grow and function properly. Though all 20 of these are important for your health, only nine amino acids are classified as essential. These are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. Unlike nonessential amino acids, essential amino acids can’t be made by your body and must be obtained through your diet. There are many vegan sources which are complete proteins containing all essential amino acids such Spirulina, tempeh, buckwheat, chia & hemp seeds, these foods provide amino acids which are in a much more natural easily absorbable state compared to non vegan sources. When you eat protein, it’s broken down into amino acids, which are then used to help your body with various processes such as building muscle and regulating immune function .

Conditionally Essential Amino Acids

There are several nonessential amino acids that are classified as conditionally essential. These are considered to be essential only under specific circumstances such as illness or stress. For example, although arginine is considered nonessential, your body can’t meet demands when fighting certain diseases like cancer . That’s why arginine must be supplemented through diet in order to meet your body’s needs in certain situations. Glutamine is another great example. 

9 Essential Proteinogenic Amino Acids

  • Histidine
  • Isoleucine
  • Leucine
  • Lysine
  • Methionine
  • Phenylalanine
  • Threonine
  • Tryptophan
  • Valine

11 Non-Essential Proteinogenic Amino Acids

  • Arginine
  • Alanine
  • Asparagine
  • Aspartic acid
  • Cysteine
  • Glutamine
  • Glutamic acid
  • Glycine
  • Proline
  • Serine
  • Tyrosine

Glutamine

Glutamine is a conditionally essential amino acid. Although normally synthesized in adequate amounts, endogenous glutamine production may be inadequate during periods of metabolic stress. Glutamine is crucial for many metabolic functions, including protein and glutathione synthesis, energy production, maintenance of optimal antioxidant status, and immune function. Glutamine regulates the expression of several genes and activates numerous proteins l-Glutamine is an immunonutrient and the preferred substrate for energy production in enterocytes and lymphocytes. Glutamine influences production of some T-cell-derived cytokines and is important for optimal lymphocyte proliferation. Notably, lymphocytes are unable to produce glutamine. If glutamine stores are depleted by ongoing immunological demands, glutathione production will therefore be inadequate. Glutamine is an important nutritional supplement when metabolic stress renders endogenous synthesis inadequate. Glutamine has been recently reported to have favorable effects on the gut microbiome and gut permeability, which may be one reason why many practitioners continue to use this supplement for IBD patients. There is a theoretical concern that glutamine could be converted to glutamate, which is an excitatory neurotransmitter. Legumes such as beans, peas and lentils are high in protein and provide a rich source of glutamine are the high-protein ones. Other glutamine-rich vegetables include spinach, parsley, cabbage and beets. High cooking heats can break down glutamine, so it is best if these vegetables are consumed raw in order to maximize their glutamine content and increase bioavailability.

Glycine

Glycine (also known as 2-Aminoacetic Acid) is an amino acid and a neurotransmitter. The body produces glycine on its own, synthesized from other natural biochemicals, most often serine, but also choline and threonine. We also consume glycine through food. This amino acid is found in high-protein foods. A daily diet should typically include about 2 grams of glycine. Glycine is a neurotransmitter with the ability to be both excitatory and inhibitory, meaning it can function both to stimulate brain and nervous system activity, or to quiet it. Glycine is considered among the most important amino acids for the body. It exerts widespread influence over our bodies’ systems, structure, and general health, including cardiovascular, cognitive, and metabolic health. As an amino acid, glycine works as a protein builder in the body. In particular, glycine enables the production of collagen, a protein that is an essential component of muscles, tendon, skin, and bones. Collagen is the most commonly occurring protein in the body, comprising roughly a third of all body protein.  It does no less than give the body its fundamental structure and strength. Collagen is the protein that helps skin maintain elasticity. Glycine also facilitates the production of creatine, a nutrient stored in and used by both the muscles and the brain for energy.  Glycine is involved in digestion, specifically in the breakdown of fatty acids in foods. It also helps maintain healthy levels of acidity in the digestive tract. Glycine is also involved in the body’s production of DNA and RNA, the genetic instructions that deliver our body’s cells the information they need to function. This amino acid helps to regulate blood sugar levels and move blood sugar to cells and tissues throughout the body, to be consumed as energy. Glycine helps to regulate the body’s immune response, to limit unhealthful inflammation and spur healing. As a neurotransmitter, glycine both stimulates and inhibits cells in the brain and central nervous system, affecting cognition, mood, appetite and digestion, immune function, pain perception, and sleep. Glycine is also involved in the production of other biochemicals that influence these body functions. In particular, glycine helps the body make serotonin, a hormone and neurotransmitter that has significant effects on sleep and mood. It also influences key receptors in the brain that affect learning and memory.  Although the body can manufacture glycine from serine and threonine, this amino acid can also be sourced from many high-protein foods. In particular, soybeans, spinach, kale, cauliflower, cabbage, pumpkin, banana, kiwi fruit, cucumber and beans. You can also find glycine supplements in the form of powders or capsules. These can be helpful in medical conditions such as prostate problems, poor memory, stroke and schizophrenia. Other supplements containing glycine are available to help treat chronic fatigue syndrome, anaemia and hypoglycaemia. These supplements can help to boost energy levels and general well-being.

Cystine

Cysteine is a proteinogenic amino acid contributing to building protein and includes the element sulphur. It can be synthesised in the human liver and is therefore not an essential amino acid. However supplements are a good way to meet the daily recommended target. This amino acid is only included to a small degree in proteins (2 %). This makes a varied diet very important to avoid cysteine deficiency. The body creates cysteine from an essential amino acid called methionine. This makes the abundance of methioninein the body a critical factor to the body’s supply of L-cysteine. Therefore it is sometimes counted as a semi-essential amino acid. This is also due to its role as a catalyst in many important metabolic cycles. Cysteine supports the synthesis of glutathione, which is highly antioxidative, and it can also be stored in this chemical form. Therefore this amino acid plays an important role in detoxification and the resulting protection of several tissues and organs. According to recent research this does not only slow down the natural process of ageing, but also helps in preventing certain diseases. These include dementia and multiple sclerosis, because there is a link between these diseases and an accumulation of toxins. L-cysteine can help to reduce inflammation of reproductive tissues and organs. This can in turn support fertility, because if the prostate or seminal vesicles are inflamed, fertility levels decline. Additionally, the antioxidant effects of NAC and associated glutathione can help to alleviate inflammation. This also contributes towards improving fertility. Cysteine’s exceptionally strong antioxidant properties have so many positive effects on the overall health, that it can be used for both prevention as well as therapy of illnesses. Many foods rich in protein usually contain L-cysteine, although in small amounts. Sunflower seeds and soy products are best suited to cover the minimum daily required amounts of  1.400 mg L-cysteine. Sunflower seeds (approximately 451 mg per 100 g) and walnuts (approximately 208 mg per 100 g). Soybeans have the highest concentration with approximately 655 mg per 100 g.

The nine essential amino acids perform a number of important and varied jobs in your body:

  1. Phenylalanine: Phenylalanine is a precursor for the neurotransmitters tyrosine, dopamine, epinephrine and norepinephrine. It plays an integral role in the structure and function of proteins and enzymes and the production of other amino acids. ( Pumpkin seeds, Tempeh, hemp seeds, buckwheat,  almonds )
  2. Valine: Valine is one of three branched-chain amino acids, meaning it has a chain branching off to one side of its molecular structure. Valine helps stimulate muscle growth and regeneration and is involved in energy production. ( oats, tempeh, nuts, seeds, buckwheat)
  3. Threonine: Threonine is a principal part of structural proteins such as collagen and elastin, which are important components of the skin and connective tissue. It also plays a role in fat metabolism and immune function. ( Tempeh, buckwheat, spirulina, chlorella, pea protein)
  4. Tryptophan: Though often associated with causing drowsiness, tryptophan has many other functions. It’s needed to maintain proper nitrogen balance and is a precursor to serotonin, a neurotransmitter that regulates your appetite, sleep and mood. (Sesame seeds, seaweed, buckwheat, tempeh, mushrooms, leafy veg, walnuts)
  5. Methionine: Methionine plays an important role in metabolism and detoxification. It’s also necessary for tissue growth and the absorption of zinc and selenium, minerals that are vital to your health. ( tempeh, buckwheat, sunflower seeds, oats)
  6. Leucine: Like valine, leucine is a branched-chain amino acid that is critical for protein synthesis and muscle repair. It also helps regulate blood sugar levels, stimulates wound healing and produces growth hormones. (Tempeh, buckwheat, legumes)
  7. Isoleucine: The last of the three branched-chain amino acids, isoleucine is involved in muscle metabolism and is heavily concentrated in muscle tissue. It’s also important for immune function, hemoglobin production and energy regulation.(Tempeh, buckwheat)
  8. Lysine: Lysine plays major roles in protein synthesis, hormone and enzyme production and the absorption of calcium. It’s also important for energy production, immune function and the production of collagen and elastin. (Pumpkin, tempeh, buckwheat)
  9. Histidine: Histidine is used to produce histamine, a neurotransmitter that is vital to immune response, digestion, sexual function and sleep-wake cycles. It’s critical for maintaining the myelin sheath, a protective barrier that surrounds your nerve cells. (Tempeh, Buckwheat, spirulina, lentils, almonds)

As you can see, essential amino acids are at the core of many vital processes. Though amino acids are most recognized for their role in muscle development and repair, the body depends on them for so much more.That’s why essential amino acid deficiencies can negatively impact your entire body including your nervous, reproductive, immune and digestive systems.

The US recommended daily allowances per 2.2 pounds (1 kg) of body weight for the nine essential amino acids are:

  • Histidine: 14 mg
  • Isoleucine: 19 mg
  • Leucine: 42 mg
  • Lysine: 38 mg
  • Methionine (+ the non-essential amino acid cysteine): 19 mg
  • Phenylalanine (+ the non-essential amino acid tyrosine): 33 mg
  • Threonine: 20 mg
  • Tryptophan: 5 mg
  • Valine: 24 mg

Soy, quinoa, hemp, chia, Spirulina and buckwheat are all plant-based foods that contain all nine essential amino acids, making them complete protein sources as well. Other plant-based sources of protein like beans and nuts are considered incomplete, as they lack one or more of the essential amino acids. However, if you’re following a plant-based diet, you can still ensure proper intake of all essential amino acids as long as you eat a variety of plant proteins each day. For example, choosing a variety of incomplete proteins such as beans, nuts, seeds, whole grains and vegetables can ensure that your essential amino acid needs are met, even if you choose to exclude animal products from your diet.