How can we strengthen our immune system?

Building up the immune system: How do our defences work?

The immune system cannot be strengthened instantly. Its performance depends on various factors, only some of which can be influenced. Rather than relying on supposed 'immune boosters', it is more sensible to support the body's natural defences and identify potential weaknesses early on.

The way our immune system functions is based on a network of organs, cells and signalling molecules. There are two types of immune response: innate and adaptive.

The innate immune system reacts immediately to pathogens. The skin and mucous membranes form the first line of defence. If these are breached, specialised immune cells recognise potential intruders and initiate initial countermeasures.

The adaptive immune system develops over the course of a lifetime. B-lymphocytes produce targeted antibodies, while specific T-cells fight infected body cells. Following infections or vaccinations, memory cells often remain, enabling a faster immune response when the body comes into contact with the pathogen again.

Both systems work closely together. It is important that the immune response is effective enough without triggering excessive inflammatory reactions.

What can lead to a weakened immune system?

Various internal and external factors can weaken the immune system and make you more susceptible to infections.

Nutrient deficiency: An insufficient supply of certain vitamins, minerals and proteins can hinder the development and operation of immune cells.

Diseases and medications: Certain chronic conditions, such as diabetes mellitus, can increase susceptibility to infection. Medications that suppress the immune system, such as those used to treat autoimmune diseases or following organ transplants, can also alter the body's natural defences.

Age and hormonal changes: As we age, our immune system changes. This can lead to a weaker response to previously unknown pathogens. Hormonal changes, such as those experienced during pregnancy or menopause, can also affect immunological processes.

Persistent stress: Long-term psychological stress, severe sleep deprivation or intense physical overexertion can alter immunological processes. The extent to which this affects susceptibility to infection varies from person to person.

Compromised protective barriers: Dry or damaged skin and mucous membranes make it easier for pathogens to enter the body. The mucous membranes of the respiratory tract play a particularly important role in defending against cold viruses.

Which measures are effective in strengthening the immune system?

Adequate nutrient intake is essential for the immune system to function properly. Vitamins C and D and zinc play a particularly important role in this regard. However, their functions differ.

Vitamin C plays a role in supporting the function of various immune cells. Good sources of vitamin C include bell peppers, broccoli, sauerkraut, citrus fruits, and berries.

Vitamin D is involved in regulating immune responses. The body produces it with the help of sunlight. During the sunnier months, 15 to 20 minutes of exposure to the face and arms daily is usually sufficient. However, since the body's own production is severely limited in winter at our latitude, it is essential to maintain adequate levels through the body's vitamin D stores and, if necessary, targeted supplementation.

Zinc is required for the development and activity of immune cells. Sources of zinc include whole grain products, legumes, nuts, meat and dairy products.

Protein, iron, selenium and other micronutrients also play an important role in immune defence. A varied diet helps to meet these requirements.

The gut microbiome, which is the entire collection of microorganisms in the gut, is also of great importance. Gut bacteria help the immune system to distinguish between harmless substances and pathogens, and keep defence cells ready for action by continuously signalling to them. At the same time, they strengthen the intestinal mucosa's protective barrier, making it harder for harmful germs to spread. A diet high in fibre, including vegetables, whole grains, legumes and fermented foods, supports a diverse gut microbiome.

As a general rule, dietary supplements are not necessary if you are getting sufficient nutrients from your diet. However, if a deficiency has been diagnosed, targeted supplementation may be beneficial. High-dose preparations, especially those containing vitamins D, C and E, as well as the minerals iron and zinc, should only be taken after consulting a doctor.

Preventive healthcare also includes age-appropriate vaccinations and quitting smoking. Vaccinations prepare the acquired immune system for specific pathogens, significantly reducing the risk of severe illness.

Furthermore, regular exercise and sufficient sleep support general health and normal immune function.

Natural treatments to boost your immune defences

Heat and cold stimuli have traditionally been used for preventive healthcare. Examples include Kneipp therapy, contrast showers, sauna sessions and ice bathing.

Contrast showers and Kneipp treatments provide targeted temperature stimuli. When the body is exposed to cold, the superficial blood vessels initially constrict and then dilate again when exposed to heat. This alternation improves vascular regulation and stimulates blood circulation.

Sauna sessions lead to a temporary rise in body temperature, activating the cardiovascular system. The heat stimulus also influences the activity of certain immune cells and the release of signalling molecules involved in regulating immune responses.

Clay baths and healing earth treatments form a core part of the naturopathy developed by Emanuel Felke. The combination of temperature and the compressive effect of the clay stimulates the body's regulatory processes. In Felke therapy, these treatments activate the body's natural defences and reduce susceptibility to infection.

Ice bathing exposes the body to an intense cold stimulus. This triggers the release of stress hormones such as adrenaline and noradrenaline, which influence the cardiovascular system and the activity of specific immune cells, among other things.

Naturopathic treatments can improve overall health and help the body adapt to changes in temperature. However, they should not be used as a substitute for medically necessary treatment or proven infection prevention measures. In the case of acute infections accompanied by fever, intense heat or cold stimuli should be avoided.

Medical consultation is required if infections occur unusually frequently, are particularly severe or last for an unusually long time. The same applies if you do not make a full recovery after an illness.