There are two types of amino acid, essential and non-essential. There are approximately 80 amino acids found in nature but only 20 are necessary for healthy human growth and function. We are made up of protein and we require adequate amounts of amino acids if we are to maintain and repair the very substance that we are made from.
We need to obtain essential amino acids from our diet and our body will produce the nonessential variety on its own if our diet is lacking in the essential type.
ESSENTIAL AMINO ACIDS.
These are Histidine (essential in infants can be made by the body in adults if needed), Isoleucine, Leucine, Lysine, Methionine, Cysteine (essential in infants, nonessential in adults), Phenylalanine, Threonine, Tryptophan and Valine.
NON ESSENTIAL AMINO ACIDS.
Alanine, Aspartic acid, Arginine, Carnitine, Glycine, Glutamine, Hydroxyproline, Norleucine, Proline, Serine and Tyrosine.
THE ROLE OF AMINO ACIDS IN THE BODY.
Amino acids help make neurotransmitters, the chemicals that convey messages in the brain and also hormones like insulin. They are needed for the production of enzymes that activate certain functions within the body and certain types of body fluid and they are essential for the repair and maintenance of organs, glands, muscles, tendons, ligaments, skin, hair and nails.
AN EXAMPLE OF ONE OF THE AMINO ACIDS.
I have often talked about tryptophan when discussing healing foods, and it is an excellent example of the role of amino acids within the body.
When we eat foods that contain tryptophan the body will use that to form the very important vitamin B3 or Niacin. Niacin is necessary for the metabolism of carbohydrates, fats and proteins to obtain the fuel we need (ATP) as well as helping to regulate cholesterol. It is necessary for the formation of red blood cells and hormones. Read more about B3 here.
When niacin is formed it continues to work with the tryptophan along with B6 to stimulate the production of the serotonin and melotonin transmitters within the brain that not only help regulate our mood but also our sleep patterns. Without tryptophan we would be more likely to suffer from insomnia and depression.
Some studies also show that tryptophan is also a natural painkiller and interestingly it may eventually be used to prevent tooth decay.
Tooth decay is usually the result of the action of our own saliva on carbohydrates that we eat. Those people whose saliva composition resulted in a rapid rate of starch decomposition in the mouth, were more likely to suffer from excessive cavities in their teeth. Those people whose saliva caused a slow decomposition of carbohydrates were found to suffer very few dental problems. Taking in dietary tryptophan has been shown to slow down this process and may well be included in toothpaste and chewing gum in the future.
Other studies indicate that autistic children suffer from a deficiency of tryptophan. Also that it might be useful as an appetite suppressant. In combination with with another amino acid, Tyrosine, it could help with drug addiction and is recommended to overcome jet lag.
DIFFERENCES BETWEEN BABIES AND ADULTS.
Due to the enormous growth rate of babies there is a difference in the essential or nonessential properties of amino acids.
An example of this is cysteine, which is considered to be essential in babies, which is why breast milk is very high in the amino acid and non-essential in adults. Due to its high antioxidant effects it may in part be responsible for the important boosting of the immune system in newborn babies that is supplied by breast milk.
When we are adults, we still require cysteine, but instead of obtaining it from our diet it is synthesised from another essential amino acid methionine.
Cysteine plays a role in our antioxidant processes protecting us from free radical damage and therefore chronic disease and ageing. It is currently being studied in relation to a number of medical conditions including peptic ulcers, liver health, the treatment of paracetamol overdose and metal toxicity.
It may also benefit respiratory disease due to its antioxidant properties but also its ability to help break up mucous. In the form of N-acetyl cysteine it may protect the body from cancer and there is a possibility that during treatment for cancer with chemotherapy or radiotherapy that it will protect the healthy cells but not the cancerous cells from any damage.
When I covered heart disease I looked at the role of homocysteine levels in the blood and how excess levels can lead to heart disease. Taking N-acetyl cysteine in supplement form may help reduce these levels as well as the LDL (lousy cholesterol levels) in the blood.
BRIEF DESCRIPTION OF SOME OF THE OTHER AMINO ACIDS AND THEIR ROLE IN THE BODY.
There is not room to cover the roles within the body of all the amino acids but here is a brief look at the diverse roles of some of the individual amino acids within the body.
Alanine – a very simple amino acid involved in the energy producing breakdown of glucose and is used to build proteins, vital for the function of the central nervous system and helps form neurotransmitters. It is very important to promote proper blood glucose levels derived from dietary protein.
Arginine – plays an important role in healthy cell division, wound healing, removing ammonia from the body, boosting the immune system and in the production and release of hormones.
Carnitine – is produced in the liver, brain and kidneys from the essential amino acids methionine and lysine. It is the nutrient responsible for the transport of fatty acids into the energy producing centres of the cells, known as the mitochondria. It also helps promote healthy heart muscle.
Creatine – is synthesised in the liver, kidneys and pancreas from Arginine, Methionine and Glycine and functions to increase the availability of the fuel we need ATP (adenosine triphosphate). It is stored in muscle cells and is used to generate cellular energy for muscle contractions when effort is required. This is why many athletes will supplement with Creatine to increase stamina and performance.
FOOD SOURCES FOR AMINO ACIDS.
The best food sources of amino acids are dairy products, eggs, fish, meat, soybeans, quinoa, nuts and seeds.