Approximately 500 amino acids exist in nature, but the body only incorporates 20 into our standard genetic code. They are proteinogenic, meaning the body uses them as building blocks to synthesize proteins. They fall under two primary categories: essential and non-essential amino acids. The body cannot produce essential amino acids and must obtain them through diet or supplements, whereas it can synthesize non-essential amino acids. These amino acids are crucial for synthesizing proteins and supporting growth, muscle tissue repair, and enzymatic and neurotransmitter functions.
Non-Essential Amino Acids:
Essential Amino Acids:
Outside of the standard 20 amino acids, the body encodes two additional ones into proteins: selenocysteine and pyrrolysine. However, they are non-standard because incorporating them involves processes beyond the traditional genetic code. PureBulk carries 18 of the 20 standard amino acids as supplements, excluding asparagine and glutamic acid. [1 - 4]
The body cannot produce essential amino acids independently. While complete protein sources such as meat, poultry, fish, eggs, and dairy contain all nine essential amino acids, most plant sources fall short of providing a complete amino acid profile. Individuals adhering to a plant-based diet must diversify their food choices to ensure a comprehensive intake of essential amino acids, incorporating items like legumes, grains, nuts, and seeds. Chlorella stands out as a notable vegetarian- and vegan-friendly complete protein. Supplements offer a straightforward and convenient method to ensure you’re meeting your nutritional needs.
Histidine is an essential amino acid that serves as a precursor to histamine. Histidine is an antioxidant that protects against heavy metal damage and helps form the myelin sheaths that protect nerves. Histidine also has anti-inflammatory and immunomodulatory properties. PureBulk carries two forms of histidine: l-histidine HCl and l-histidine base. L-histidine HCl combines histidine with hydrochloric acid, which may be easier for people with sensitive stomachs to digest. [5 - 9]
As a branched-chain amino acid (BCAA), isoleucine is essential for protein synthesis, muscle repair, and energy regulation. Athletes and fitness enthusiasts often take it as a supplement to support muscle growth, enhance exercise performance, and reduce exercise-induced fatigue. [10 - 12]
Leucine is another BCAA and is essential for protein synthesis and muscle repair. It is particularly adept at stimulating muscle protein synthesis, making it popular among those engaged in resistance training. [11, 13, 14]
Like all essential amino acids, lysine is important for protein synthesis. However, it also participates in collagen formation, calcium absorption, and immune function. Animal studies show it also supports overall antioxidant capacity. Additionally, several clinical trials reported that it’s an effective method to reduce cold sore severity, duration, and likelihood of reoccurrence. [15 - 23]
Outside of its role in protein synthesis, methionine contains sulfur and is a precursor for other sulfur-containing compounds in the body. Sulfur is crucial for numerous metabolic processes, such as modifying DNA, protecting tissues, and ensuring proper cellular function. Methionine is necessary for continually initiating new protein synthesis within cells as older proteins degrade. Specifically, it kickstarts new protein production in muscles, particularly after exercise-induced damage. PureBulk carries two types of methionine: L-methionine and DL-methionine. DL-methionine is a combination of the proteinogenic l-methionine and the non-proteinogenic form d-methionine. [24 - 27]
Phenylalanine is a precursor to tyrosine and is essential for synthesizing neurotransmitters like dopamine and norepinephrine, all of which influence your mood, stress responses, and cognition. Individuals are also prone to mood disorders without enough of these neurotransmitters. PureBulk carries two types of phenylalanine: L-phenylalanine and DL-phenylalanine. [28 - 35]
Threonine is vital for protein synthesis and contributes to maintaining proper protein structure in the body. It supports collagen formation, a crucial protein for skin, connective tissues, and joint health. It also enhances the immune system via its involvement in antibody and mucin production. Antibodies are proteins that recognize and neutralize pathogens like bacteria and viruses, whereas mucin is a glycoprotein that forms a protective layer in mucous membranes. [36 - 42]
Tryptophan is a precursor to serotonin, a neurotransmitter that can promote relaxation and improve mood. Tryptophan may also improve sleep. It is the precursor to 5-HTP, which the body uses to make melatonin. Melatonin is an essential hormone for the sleep-wake cycle. [43 - 47]
As a BCAA, valine is essential for protein synthesis, muscle repair, and energy regulation. Like isoleucine, people take valine to support muscle growth, exercise performance, and faster muscle recovery after intense workouts. Valine can also benefit exercise endurance. [11, 48, 49]
Conditionally essential amino acids are usually non-essential, as the body can synthesize them under normal conditions. However, certain circumstances or health conditions can limit the body's ability to produce these amino acids, such as illnesses, trauma, metabolic disorders, or deficiencies in precursor amino acids or enzymes. Dietary intake of these amino acids becomes essential during those specific conditions. [50]
Examples of conditionally essential amino acids include:
Arginine is usually a non-essential amino acid, but it becomes conditionally essential during periods of rapid growth, trauma, or illness when the body's demand for arginine exceeds its production capacity. It helps synthesize nitric oxide for better blood flow, cardiovascular health, and exercise performance. [50, 51 - 54]
The body synthesizes cysteine from methionine, and a methionine deficiency or certain metabolic disorders can limit its production. Cysteine contains sulfur, which is crucial for forming disulfide bonds in proteins. These bonds are critical for protein structure and stability. [50, 55 - 59]
Glutamine is the most abundant amino acid in the blood. However, the demand for it may exceed the body's ability to produce it during certain conditions such as critical illness, severe trauma, or intense exercise. It is a significant fuel source for intestinal cells. Glutamine also supports immune function by maintaining the intestinal barrier, ultimately preventing toxins and bad bacteria from invading the gut. Athletes can also benefit from glutamine supplements. Studies show that glutamine reduces post-workout muscle soreness for a faster recovery. [50, 60 - 68]
While glycine is usually non-essential, it can become conditionally essential during specific physiological states, such as certain diseases or metabolic disorders. Although it is the simplest among the amino acids, it’s crucial for synthesizing glutathione. Glutathione is the most potent antioxidant in the body that protects cells against free radical damage and oxidative stress. The body also uses glycine in the creatine synthesis process. Creatine is crucial for producing adenosine triphosphate (ATP) for energy and can enhance muscle strength, size, and power significantly. Showcasing its diverse functions, glycine is one of the three primary structural components in collagen. [50, 69 - 75]
Proline is generally considered non-essential. However, it may become conditionally essential during increased demand for collagen synthesis or wound healing. Like glycine, it is crucial for collagen synthesis and maintaining connective tissues. It contributes to the structure and flexibility of proteins and helps strengthen heart muscles. [50, 76 - 78]
The body can usually synthesize serine from glycine or 3-phosphoglycerate. However, it can become essential during periods of rapid growth, pregnancy, certain disease states, or in the presence of glycine deficiencies. Serine helps synthesize the nucleotides that build DNA and RNA and is a precursor to several other amino acids, including cysteine, glycine, and tryptophan. Serine also relieves oxidative stress by supporting glutathione synthesis. [50, 79 - 83]
The body usually synthesizes tyrosine from phenylalanine. Individuals with phenylketonuria (PKU) have difficulty metabolizing phenylalanine, and tyrosine can become conditionally essential for them. Tyrosine is a precursor to neurotransmitters like dopamine and norepinephrine, making it important for mood regulation and cognitive function. Studies show that tyrosine is particularly helpful at maintaining cognitive capacity while experiencing cognitively demanding or stressful situations. [84 - 92]
The conditional essentiality of these amino acids emphasizes the importance of a balanced diet, especially during periods of increased metabolic demand or specific health conditions. Obtaining these amino acids through dietary sources or supplements may be necessary to support optimal health in these situations.
Barring the conditions outlined above, arginine, cysteine, glutamine, glycine, proline, serine, and tyrosine are usually non-essential amino acids. The other non-essential amino acids include:
L-alanine is integral to glucose production and energy metabolism. The body releases BCAAs during prolonged exercise. Their carbon backbones act as a fuel source, while their nitrogen portion helps form alanine. The alanine then converts to glucose in the liver. The muscles use this glucose for energy to enhance endurance and exercise performance. [93 - 95]
Aspartic acid participates in the citric acid cycle to produce ATP for energy and the urea cycle to detoxify ammonia. Animal studies show it stimulates sex hormone production, including testosterone, growth hormone, prolactin, and luteinizing hormone. [96 - 102]
While all 20 amino acids perform important functions, the body relies on dietary sources to obtain the nine essential amino acids. These essential amino acids are pivotal for numerous intricate processes, such as serving as precursors to specific neurotransmitters, participating in collagen formation for skin and joint health, and stimulating muscle protein synthesis. Additionally, they contribute to crucial functions like antioxidant protection, immune enhancement, and the initiation of new protein synthesis, particularly in muscles following exercise-induced damage. Health supplements are valuable aids to meet these nutrient needs by ensuring a balanced intake for optimal health and well-being.
