Proteins are one of the most important building blocks of the human body, where they take over many functions. They are found in every cell and are responsible for the development of the skin, connective tissue and muscles. They regulate the oxygen and nutrient transport in the cells and strengthen our immune system. In fact, a problem-free energy and build-up metabolism would hardly be possible without certain enzyme proteins, which act as biological catalysts.
A protein itself consists of a combination of amino acids whose variants are found in all living organisms.
Amino acids – which ones are there?
An amino acid is a chemical compound with two functional groups. The amino group contains nitrogen and hydrogen, the carboxy group carbon, oxygen and hydrogen in different compositions. For us humans, 20 amino acids are of particular interest, although many more variants occur in nature. They are also called proteinogenic (= “tissue forming“).
The 20 protein building blocks are in alphabetical order:
- Aspartic acid
- Glutamic acid
Subdivision of the protein building blocks into three classes
The 20 named acids are divided into three classes based on chemical principles and their importance for our nutritional physiology:
And this into essential, semi-essential and non-essential amino acids.
We would like to briefly describe the differences.
Our body cannot produce these eight variants of the essential amino acids itself:
- and Tryptophan
Therefore, we must necessarily ingest them through food or through appropriate food supplements. They are mainly responsible for the build-up of muscles, in which, for example, non-essential protein components hardly play any role.
Under optimal health conditions, the human organism can produce semi-essential amino acids from the essential ones. However, production decreases with adverse factors such as stress, periods of growth or serious illness. In such cases, we must therefore increasingly take them in with our food.
Non-essential amino acids
With a balanced diet and other healthy lifestyles, the body produces the non-essential protein building blocks itself in sufficient quantities. So they do not have to enter the organism through food.
How do amino acids in the diet become endogenous proteins?
We need amino acids to build up the body’s own protein building blocks. In order to extract an amino acid from the proteins in the diet, several steps have to be taken. The dietary protein is broken down by enzymes in the intestinal tract.
The acids released in this process reach the liver via the bloodstream. There they are then available to the organism for the formation of endogenous proteins.
What is the amino acid pool?
Unlike fats and carbohydrates, we humans cannot store proteins directly. Only a certain amount of freely available amino acids can be stored in the so-called amino acid pool. This means that we must constantly supply amino acids with our meals if we want to prevent the breakdown of the body’s own protein.
As soon as we consume more protein than our metabolism needs, the excess amino acids move into the pool after digestion. If it is already filled, the acids are used to generate energy. Most of the nitrogen contained in it is excreted with the urine.
How high is the amino acid requirement?
The World Health Organization (WHO) recommends a daily intake through a balanced diet of around 184 mg per kilogram of bodyweight. This corresponds to about 15 g for a person weighing 80 kg. With a combination of vegetable and animal protein sources, this value can be achieved without any problems.
Experts describe sources that supply the organism sufficiently with essential amino acids as “complete protein sources“. These generally include animal foods, while plants often lack one or more essential acids.
Vegans, in particular, may pay special attention when taking amino acids. You may combine fruit, vegetables and other meatless dishes in such a way that they complement each other in terms of their amino acid content.
From amino acid to protein
Proteins are created from amino acids in highly complex chemical processes. Our muscles, skin and every other type of body tissue depends on proteins – and therefore also on amino acids – as a basic building material. The respective amino acid sequence of a protein is stored in the DNA as a code and has hardly changed during evolution.
In the ribosomes of cells, the “production machines” for proteins, the information from the DNA is used to form chains of amino acids. This is where the protein molecules finally grow.
A low-protein diet causes deficiencies which the organism counters by breaking down the body’s own protein. Muscle atrophy then occurs in such situations. Numerous experts assume that ageing processes of the skin are also related to our protein metabolism.
However, the exact connections have not yet been conclusively researched scientifically.
The importance of proteins for our metabolism
How important proteins are for our bodies is shown by the fact that they are found in every cell. As a rule, they make up more than 50% of our “dry weight“. In a figurative sense, they can be described as tools the size of a molecule and, depending on their structure, take on very different tasks.
They enable cell movements, transport metabolites (the intermediate products of metabolism), catalyse chemical reactions and recognise signalling and messenger substances. They are also essential for the healing of diseases or wounds. In addition, the muscles, heart, brain, skin and hair consist mainly of proteins.
In accordance with their functions, the following proteins can be distinguished:
- structural proteins
- motor proteins
- signalling proteins
- transport proteins
- storage proteins
- enzyme proteins
Proteins as the basis for other important substances
Two examples illustrate the importance of proteins – and thus also of the amino acid complex – for our organism.
- As a neurotransmitter, the messenger substance serotonin ensures the transmission of certain signals to receptors in our brain. It is closely related to good sleep, to calmness and to our mood in general. If there is a lack of the protein serotonin, we sleep badly and usually do not have the best mood. However, tryptophan, an essential amino acid, is mainly responsible for the formation of serotonin. It must be taken in with food, as the body cannot produce it itself.
- The important thyroid hormone T4 is also produced in a conversion process from the non-essential amino acid tyrosine. T4 controls numerous bodily functions and metabolic processes, for example, energy metabolism or adaptation to cold. The hormone is involved in the splitting of fats (lipolysis) and provides energy for the body from fatty acids and sugars.
How high is our protein requirement?
The need for protein – based on body weight – is highest in the growth phases after our birth.
An infant in the first month needs about 2.5 g per kilogram of bodyweight. After one year of life about 1.3 g/kg is sufficient. The demand for small children is higher than for older children or adolescents; for younger adults, it is lower than for seniors over 65 years of age. Increased intake is recommended for pregnant women and nursing mothers.
Here are the recommendations of the German Society for Nutrition at a glance:
- Infants in the first month of life: 2,5 g/kg
- Infants from the age of 12 months: 1,3 g/kg
- Older children: 1,0 g/kg
- Adolescents: 0,9 g/kg
- Young adults: 0,8 g/kg
- Seniors over 65 years: 1,0 g/kg
- Pregnant women: 1,0 g/kg
- Nursing mothers: 1,2 g/kg
What happens if there is a protein deficiency?
If a person consumes too little protein, numerous symptoms, complaints and diseases can occur. These include reduced hair pigmentation, growth retardation, liver enlargement, muscle weakness and mental apathy. A permanent lack of protein can also lead to death, depending on the previous constitution and the expiry of a certain period of time.
In industrialized countries, protein deficiency is rare due to the good supply of food, unless people deliberately choose a diet that is low in protein. In Germany, for example, the average mixed diet contains about 100 g of protein per day, more than enough for an adult.
Food supplements containing amino acids
People who live a normal life and have a balanced diet need not fear a lack of protein. However, there may be phases and situations in life when your protein requirements are higher. In such cases, food supplements containing amino acids can be a useful aid.
Especially the following people can benefit from amino acid preparations:
- People who are on a reduced-calorie diet
- Athletes, especially if they not only want to maintain muscles but also build them up
- older persons
- people affected by illness and stress
Amino acids and proteins are indispensable
With this text, we would like to show you how important amino acids and proteins are for the functions and the structure of our human organism. Protein deficiency leads to serious diseases in the long run. In order to produce the body’s own protein, which cannot be taken in with food, we need the amino acid complex. However, we are forced to supply a part of it from outside, as we cannot generate all acids on our own.
Each individual amino acid of the 20 protein building blocks, therefore, has a special significance.
If you would like to take up these important building blocks through dietary supplements, please make sure that they are of high premium quality. As a manufacturer, we follow, for example, the recommendations of the WHO and recognised scientists. The agents are usually available in powder form or as pressed pellets. Please pay attention to products that are free of additives, as these can have a negative effect on bioavailability.