Amino acids and their effects

Amino acids are organic compounds. They are essential for life and play an important role in many biological processes. The basic framework of all amino acids comprises compounds made of hydrogen (H), nitrogen (N), carbon (C) and oxygen (O). Amino acids also consist of an amino group (NH2), a carboxyl group (COOH), and a remainder that varies from one type of amino acid to another. This remainder makes every amino acid unique and influences what function it has in the body.

How many amino acids are there? There are more than 500 natural amino acids in total. The twenty proteinogenic amino acids are important to humans in particular: they are the building blocks for proteins.

What are essential amino acids?

The body cannot produce essential amino acids itself. This means it is reliant on absorbing essential amino acids from food. This list provides an overview of essential amino acids:

• Isoleucine: the body uses isoleucine to build other amino acids. It supports energy regulation and immune function. This essential amino acid also influences muscle metabolism.
• Leucine: plays a role in producing growth hormones and regulates blood glucose levels.
• Valine: valine is involved in building muscle. As such, this amino acid can assist indirectly with weight loss. This is because the more muscle you have, the higher your metabolic rate. What’s more, valine helps the body to obtain energy and plays a role in tissue regeneration.
• Lysine: the effect of L-Lysine is multifaceted: it stimulates the immune defences and healing mechanisms. This amino acid also affects muscle development and bone growth, and influences the skin and nails. It may also help combat hair loss, because it stimulates collagen production.
• Methionine: is important for the fat metabolism and, among other things, plays a role in the production of neurotransmitters. Neurotransmitters are biochemical substances that transmit stimuli from one nerve cell to another nerve cell or to a cell.
• Phenylalanine: is used by the body to produce neurotransmitters or tyrosine, another type of amino acid.
• Threonine: this amino acid helps to regulate acid formation in the body. It also forms part of antibodies, elastin and collagen.
• Tryptophan: is important for maintaining the body’s nitrogen balance and supports the production of serotonin. L-tryptophan therefore has an impact on our emotional state. This amino acid also regulates sleep. That’s because tryptophan is a precursor of melatonin – a hormone that plays a central role in the sleep-wake cycle. As such, this amino acid may help with sleep disorders.

This list contains all eight essential amino acids. However, there are also lists that feature nine essential amino acids. These count histidine among the essential amino acids. Histidine is essential for infants.

Please note: the “L” before these amino acids stands for their chemical structure. There are also D-shaped amino acids. But only L-shaped amino acids are used by the body.

What are semi-essential amino acids?

Your body produces semi-essential amino acids itself. However, under certain conditions, it may not produce enough of these – for instance, if you are pregnant or suffer from certain disorders such as high blood pressure.

What are the benefits of semi-essential amino acids? We explain these below using two examples:

• Arginine: is involved in the production of nitrogen monoxide. This in turn lowers blood pressure and enlarges our vessels.
• Histidine: has an impact on numerous metabolic processes in your body. Histidine also helps your body to produce its own histamine. This is a neurotransmitter that regulates the digestion and immune defences, among other things.

What are non-essential amino acids?

Your body also produces non-essential amino acids itself. How many non-essential amino acids are there? There are 11 to 12 in total, eight of which are often termed semi-essential. Non-essential amino acids are responsible for different bodily functions:

• Alanine: helps the body to produce glucose and to transport amino nitrogen in the blood.
• Asparagine: the body uses this amino acid to produce asparagine acid.
• Asparagine acid: this amino acid serves as a neurotransmitter.
• Cysteine (also classed as semi-essential): is a constituent part of glutathione, an antioxidant. Cysteine also helps to produce taurine. Taurine is important for the cardiovascular system.
• Glutamine (also classed as semi-essential): is important for the immune cells.
• Glutamine acid (glutamate): serves as a neurotransmitter and a basis for other amino acids.
• Glycine (also classed as semi-essential): helps the liver to detox the body and form collagen. This amino acid also helps the body to produce red blood pigment.
• Proline (also classed as semi-essential): ensures robust connective tissue and forms a constituent part of cartilage.
• Serine: acts as a glue that holds cells together. By doing so, it helps the cells to stay healthy.
• Tyrosine (also classed as semi-essential): tyrosine is a precursor of the neurotransmitters dopamine, adrenaline and noradrenaline.

Our daily essential amino acid requirements vary from one amino acid to another. For instance, our daily tryptophan requirements range from 4 to 5 mg per kilogram of body weight, whereas leucine requirements amount to roughly 40 mg per kilogram of body weight.

It helps to follow your daily protein requirements, because proteins are made up of amino acids. Generally speaking, adults below the age of 65 should ideally get 0.8 g of protein per kilogram of body weight. For those older than 65, daily requirements amount to roughly 1.0 g per kilogram of body weight. Please note that these values are not universally applicable: you may need more or less protein depending on your physical activity, age or the state of your health. Pregnancy affects the recommended protein intake too. You doctor can help you to determine your daily protein needs.

A lack of amino acids – essential or non-essential – can cause various symptoms:

• Amino acid deficiencies often result in a drop in performance.
• Those affected are often tired and feel weak.
• Some experience hair loss.
• Insomnia and sleep disorders are other signs of an amino acid deficiency.
• A lack of amino acids may also potentially cause side effects such as mood swings and anxiety conditions.
• Blood sugar fluctuations may also result from an amino acid deficiency.
• Amino acid deficiencies may result in restricted thyroid function.
• Those affected have less of an appetite and may even experience vomiting.

Causes of an amino acid deficiency

There are various factors that can cause a deficiency in essential or non-essential amino acids: e.g. gastrointestinal disorders or a lack of variety in the diet. What’s more, our amino acid and/or protein requirements are increased during certain stages of life. This is the case during pregnancy for example. A deficiency may therefore occur during these stages.

If you have a healthy and balanced diet, there’s generally no need to take amino acids in supplement form. However, it may be sensible depending on your age, state of health, life situation (e.g. during a pregnancy) or physical activity. Ask your doctor whether they would recommend taking relevant food supplements in your case. Look out for good quality when buying amino acid products.

Amino acids support numerous bodily functions, making them essential to survival. You can cover your daily needs through a varied diet, because amino acids are contained in different foods. You should contact your doctor if you experience any of the symptoms mentioned above. They will help you to determine whether this is being caused by an amino acid deficiency or something else.