The Amino Acid Merry-go-round – Part 1
Hello Friends:
In understanding the role of dietary protein in our health and development, it’s important to realize that protein is basically a general category with more details as to its amino acid makeup and the ratios of those amino acids as crucial to its functional and structural-building benefits.
There are roughly about 500 amino acids that have been identified in nature, but just 20 amino acids make up the proteins found in the human body.
The ones for our body are categorized as Essential, Non- Essential, and Conditionally Essential–a very intriguing category.
The essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.
The Essential amino acids are a bit misleading since all amino are necessary but it is more about the origin, however, the essential amino acids can only be derived from our diet, and the non-essential can be synthesized by our bodies with the proper building blocks from carbohydrates and food nitrogen sources.
Nonessential amino acids include alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine.
Conditional amino acids, as said, are very interesting, but are usually not essential, except in times of illness and stress. Conditional amino acids include arginine, cysteine, glutamine, tyrosine, glycine, ornithine, proline, and serine.
Glutamine, for example, is the most abundant amino acid (a building block of protein) in the body as well as a “conditional amino acid”. The body can make enough glutamine for its regular needs. But during times of extreme stress (the kind you experience after heavy exercise or an injury), your body may need more glutamine than it can make. Most glutamine is stored in muscles, followed by the lungs where much of the glutamine is made.
Glutamine is important for removing excess ammonia (a common waste product in the body). It also helps your immune system function and may be needed for normal brain function and digestion.
You can usually get enough glutamine without taking a supplement because your body makes it and you get some in your diet. Certain medical conditions, including injuries, surgery, infections, and prolonged stress, can lower glutamine levels. In these cases, taking a glutamine supplement may be helpful.
What about food sources from the origin proteins for amino acids?
Not surprisingly, animal sources for the essential amino acids making complete proteins are well accepted and easily available, however, there are some plant proteins such as quinoa, buckwheat, hemp seeds, chia seeds, and spirulina. are complete proteins—which means they contain all 9 essential amino acids that we need.
What is truly interesting, there is a whole subdivision of study in this area using various isolated and independent amino acids and noting their unique effects outside of their function in being a building block for a protein.
This is relevant to all amino acid classifications.
For instance, glycine is the most important and simple, nonessential amino acid in humans, for example, and many animals. Generally, glycine is synthesized from choline, serine, hydroxyproline, and threonine through interorgan metabolism in which kidneys and liver are primarily involved.
As an amino acid, glycine contributes to cellular growth and health. Glycine is one of the amino acids essential to the body’s synthesis of the antioxidant glutathione. Cells produce glutathione in order to fight free radicals that can otherwise cause oxidative stress and damage cells, proteins, and DNA.
L-Threonine is an essential amino acid that helps to maintain the proper protein balance in the body. It is important for the formation of collagen, elastin, and tooth enamel, and aids liver and lipotropic function when combined with aspartic acid and methionine.
L-Tryptophan is an essential amino acid, but by itself in more pharmacological amounts, has much influence on mood, sleep, and psychological state.
There is a massive amount of literature citing the research and therapeutic uses of individual amino acids in roles beyond their nutritional roles–this is a whole field in itself and is fascinating and complex.
Then there are interesting, odd, effective amino acids not needed nor produced by our bodies–for instance amino acid called L-theanine(chemically known as γ-glutamyl-ethyl amide).
L- Theanine, is a non-protein amino acid (which means it’s not a building block for a protein) mainly found naturally in green tea (Camellia sinensis) and some mushrooms (Boletus badius).
Theanine is related to glutamine in functional roles, not structure, and is speculated to increase levels of GABA, serotonin, and dopamine.-theanine (γ-glutamyl-ethyl amide), and has been shown to affect brain functions by relieving stress disorders, improving mood, and maintaining normal sleep.
There is sometimes confusion between L-Threonine, an essential amino acid, and L-Theanine, not an essential ( nor non-essential amino acid!) and is only uniquely found in some plants and teas. Just briefly the difference in function L-threonine improves cognitive function and muscle health while L-theanine promotes relaxation and provides calming effects.
PART ONE reviews amino acids with a broad brush, in PART TWO, will more specifically review the essential amino L-leucine and its role in one of the most important aspects of aging or inactivity which is bone, skeletal muscle, and muscle strength health.