Our immune system
The human immune system is a complex network involving various organs, different cells and a multitude of molecules. It serves to defend the body against pathogens such as bacteria, viruses, parasites and fungi and to remove foreign substances as well as defective body cells.
We have an innate and an acquired immune system.
The innate immune system is our first line of defence and fends off pathogens. That is why it is also known as the non-specific defence system. It employs immune cells, such as scavenger cells or natural killer cells, as well as antibacterial substances in the blood and in the mucous membranes of the respiratory tract. The skin is a mechanical wall of defence against pathogens and also part of the innate immune system, whose main function is to ward off harmful substances and germs that enter the body through, for example, the skin or the digestive system.
The acquired immune system develops over the course of our life. This learned, specific immune defence mechanism is also known as an adaptive immune response. It allows the body to fight pathogens in an even more targeted and effective way. B and T lymphocytes are among the most important immune cells of the specific immune system.
They can destroy a pathogen themselves or play a part in the formation of antibodies, which the specific immune system uses to target particular, previously encountered pathogens. Since this specific defence is capable of learning and adapting, it means the body can also fight pathogens that change, or mutate, over time.
How an immune response takes place
To enable an immediate defence response to a potential pathogen, our immune system must first correctly identify the uninvited intruder. Here, it is especially important for the immune system to correctly distinguish between foreign cells and our own body’s cells. After all, the goal is to protect rather than attack the body.
The immune system recognises aliens by their surface, the antigens. Once a foreign intruder is identified, the immune reaction commences.
What is important is whether our immune system remembers the pathogen from previous infections:
- Initial infection: If the body encounters a pathogen for the first time, it will first activate its innate immune defence: scavenger cells, or macrophages, identify the foreign intruder and absorb and process it. Next, the macrophages initiate the production of antibodies by presenting components of the foreign material on their own surface. B lymphocytes recognise these antigens and start to produce specific antibodies against the pathogen.
- Subsequent infection: The antibodies produced in reaction to the initial infection remain in our blood and allow for a quick and targeted response in the event of another infection by the same pathogens.
Various factors affect the strength of our immune system
Not all immune systems are equally fast and effective in their response. This is because different factors influence the function of our immune defence:
- genetic factors
- psychological factors
Diet for a strong immune system
Diet is crucial for a well-functioning immune system.
A balanced, plant-based, mixed diet is an ideal basis for supplying the body with all key nutrients and keeping in shape the defence team we depend on for our survival. It is especially important to avoid nutrient deficiencies, because an insufficient supply of immune-relevant vitamins, minerals and trace elements can, for example, lead to a higher susceptibility to infection.
Micronutrients that are known to be important for the immune system include vitamins C and D along with the trace elements zinc and selenium. Vitamins B2 and biotin also play an important role in the immune defence because they help maintain normal skin and mucous membranes, which are part of the innate immune system and serve as a protective outer layer against pathogens.