The vital building blocks of life are the organic compounds known as amino acids. They link together to form chains, creating the foundations for peptides and proteins, as well as providing an alternative energy source for cells.
You will learn
- How amino acids are classified
- Which roles amino acids play in the human body
- Which foods contain lots of amino acids
How Amino Acids Support Your Overall Well Being
After water, amino acids in the form of proteins constitute the largest component of cells, muscles and other tissues within our body.
In addition to protein synthesis, amino acids are also involved in a wide range of physiological and pathological processes necessary for optimal body function.
Amino acids are made from a central carbon atom, an amino group (-NH2), a carboxyl group (-COOH) and a side change. The key components of an amino acid are hydrogen, carbon, nitrogen and oxygen. Additional elements can be found within the side chain and these variations can be used to distinguish between the different amino acids.
Amino Acid Classifications
There are a range of classifications that can be used to group amino acids. Structurally, they can be divided based on the location of the amino functional group, either as alpha, delta, beta or gamma. They can also be classified depending on the type of side chain group (acyclic, aromatic, sulphur or hydroxyl-containing, aliphatic), their polarity, and whether they are basic, neutral or acidic.
However, one of the most practical amino acid classifications comes from understanding how we source these vital organic compounds. The common amino acids needed by humans are classified into three categories: essential, non-essential, and conditional or semi-essential.
Also, several amino acids are classed as semi-essential for children due to underdeveloped metabolic pathways. These include: R, tyrosine and cysteine.
By understanding how we obtain amino acids, it’s possible to learn how to better support a healthy body and enhance our well-being. It also offers an opportunity to help safeguard our body from various diseases.
The Many Roles of Amino Acids
Amino acids play many vital roles within our body. Below, we have outlined some of the various functions performed by amino acids.
Scientists have identified more than five hundred different amino acids within nature. However, only twenty-two are involved in the process by which RNA (derived from DNA) makes protein (known as translation). These types of amino acids are referred to as proteinogenic amino acids. Twenty of these amino acids are considered common, while the other two, pyrrolysine and selenocysteine, are integrated into proteins using unique synthetic mechanisms.
Proteinogenic amino acids contribute to structural components of your body, including skin, brain, muscle, eyes, hair, and internal organs. Haemoglobin, enzymes, myoglobin, antibodies and many hormones are molecules incorporating proteins. The unique structures of the various proteins are determined by the sequence of associated amino acids.
Amino acids play a duel role in our immune system. They not only help to protect individuals from infections and other illnesses, they also help to regulate and moderate over reactions, such as autoimmunity and inflammation.
There are many different amino acids that play a vital role in promoting a healthy immune system. Arginine supplementation can improve cellular immune mechanisms, especially T-cell function. Branch-chained amino acids (leucine, isoleucine and valine) as well as glycine, glutamine, cysteine and theanine, all help to reduce inflammation and boost immunity. These are just a few examples of the many amino acids that help protect and heal the body.
These molecules are responsible for stopping the oxidation of other molecules and the production of harmful free radicals. These free radicals damage cells, contribute to aging and increase our susceptibility to disease. There are several important amino acids with antioxidant properties: glutathione, lysine, methionine and glycine. Glutathione is an extremely potent and important antioxidant. It helps to boost the immune system and flush free radicals out of the body. Lysine and methionine are precursors to carnitine, which supports antioxidant activity and boost mitochondrial function.
The most abundant neurotransmitters within the brain are amino acids and they are responsible for the majority of fast signalling between neurons. Glutamate and aspartate are particularly important, along with glycine and GABA.
Amino acids can be used as a source of cellular energy. If a protein is no longer required or damaged, it can be converted back to the original amino acid constituents and be broken down into molecules for oxidation.
Nitric oxide (NO) synthesis
Without the amino acids R and citrulline, our body wouldn’t be able to produce NO. In the absence of this reactive gas, our body wouldn’t function. NO is critical signalling molecule involved in many cellular and physiological processes, including, but not limited to: blood circulation, immune defence and neurotransmission. NO has been extensively studied and acclaimed as the ‘Molecule of the Year’ in 1992 due to its fundamental role in immunology, neuroscience and physiology. Consequently, citrulline and R are two vital amino acids necessary to support our body.
Sources of amino acids
The body does not store amino acids in the way that it stores excess starch and protein as fat for later use. Consequently, amino acids must be constantly replaced as they are used.
While a large portion of the amino acids we require are produced from within the body, essential amino acids need to be sourced elsewhere. Our diet is the best supply of amino acids.
The richest sources of amino acids are animal derived and come from foods such as poultry, meat, seafood, dairy and eggs. Plant sources of amino acids are also important, although different plants offer different amino acids. For example, beans are rich in lysine, while grains are lysine poor.
To ensure that your body has access to all the necessary amino acids it’s essential to have a balanced diet. Fresh, raw foods are ideal as they maintain a high concentration of amino acids.
Foods that have been frozen and cooked are exposed to cellular damage due to oxidation and this can reduce the nutritional benefits. Highly processed foods are very poor sources of amino acids and should only been consumed in moderation.
There are a number of foods commonly referred to as ‘superfoods’ due to their rich amino acid content and antioxidant properties. Regularly including these foods in your diet can help to support all the physiological and pathological processes needed for the body to properly function.
They will also help to boost the immune system and overall well-being. Some of these important foods include legumes, pulses, salmon, spinach, blueberries, broccoli, walnuts, almonds, avocados, green tea, cherries, cranberries, chia seeds, pumpkin seeds, whole grains, and spirulina. This is just a small sample of the many foods that offer great benefits to our body.
It’s wise to keep your diet in balance and not to over indulge in one particular amino acid rich food source. While the body can expel surplus amino acids or convert them to energy, a continuous, excessive supply can overwork the kidneys.
This can be problematic for anyone with an impaired kidney function. A sensible, balanced diet will eliminate this problem.
If you’re unable to maintain a regular, balanced diet there are plenty of amino acid supplements available. These can be taken to ensure that you’re getting an adequate supply of essential amino acids and help to support the body during periods of illness or prolonged stress.
If you have any underlying health issues it’s recommended that you consult a health care professional before taking supplements.