What can weaken the immune system?

The immune system protects our body from harmful influences: harmful substances, unwanted cellular changes, and pathogens.

As long as it functions properly, we take practically no notice of our immune system—but if it is weakened and can no longer defend itself adequately, we are in constant danger of becoming ill.

In this article, you will learn

1. what we actually mean by the immune system
2. how the immune system can be weakened
3. the consequences of a weakened immune system

The immune system—a brief introduction

Our immune system is not a single body part, but rather the interaction of an entire system comprising various organs and blood cells:

• Skin and mucous membranes
• Tonsils
• Thymus
• Lymphatic system
• Intestines
• Spleen
• Bone marrow
• Antibodies in the blood
• Phagocytes and killer cells

In principle, a distinction is made between two types of immune system: the innate and the acquired. Both systems work closely together and complement each other.

We are born with the innate immune system. With the help of immune cells such as phagocytes- or killer cells, it fights harmful substances and harmful pathogens that enter our body through the skin or digestive tract.

The acquired immune system develops over the course of our lives as we are exposed to various viruses, bacteria, etc. The immune system reacts through contact with antigens, which include proteins found on the surface of pathogens.

These antigens bind to receptors on our immune cells and trigger a chain of cellular processes. After contact with a pathogen, the corresponding information is stored. In the event of renewed contact, this information can be retrieved, allowing the body to quickly begin its defense.¹

However, there is a problem: The proteins mentioned above are also found on the surface of our body cells. Our immune system normally recognizes them as harmless.

Nevertheless, it can happen time and again that the body's own, healthy cells are misclassified, resulting in an autoimmune reaction. This can lead to autoimmune diseases such as multiple sclerosis, psoriasis, systemic lupus erythematosus or rheumatoid arthritis.

Allergies also develop as a result of a disorder of the immune system. In this case, there is an excessive reaction to foreign substances that are not actually harmful (e.g., pollen, animal hair, or food).²

What weakens our immune system?

If harmful substances and pathogens are not fought off as they should be, this indicates a weakened immune system.

This is evident not only through increased susceptibility to infection. Fatigue, exhaustion, and concentration problems can also indicate a weak immune system.

There are various underlying conditions, such as metabolic disorders or chronic respiratory diseases, that negatively affect the function of the immune system.

Other causes of a weakened immune system include:

Unhealthy diet or insufficient nutrient intake

At the University of Bonn, researchers fed mice a “Western diet” high in fat and sugar and low in fiber.

The result: The animals developed an inflammatory reaction throughout the body, almost as if following a severe bacterial infection. Even after four weeks of a species-appropriate diet, the body still remembered the unhealthy food through a kind of “fast-food sensor” in the immune cells and remained in a state of alarm.

This sensor is known as the inflammasome and is responsible for releasing inflammatory messengers. In the long term, these not only weaken the immune system but also promote vascular diseases or the development of type 2 diabetes.³

Sleep deprivation

Just three hours of lost sleep weaken our bodies and make them more susceptible to infections. This was established by a research team from the universities of Lübeck and Tübingen.

The reason lies in the T cells responsible for immune defense. They circulate in our blood, search for pathogens, and eliminate them. This function is demonstrably lost when there is insufficient sleep.⁴

Chronic stress

Constant stress and psychological strain keep the body in a state of chronic alarm, which also affects the immune system.

According to Dr. Samuel Gehrke from University Hospital Zurich, immune cells lose their ability to multiply due to the release of stress hormones. As a result, fewer pathogens can be destroyed.⁵

Nicotine and alcohol

Nicotine interferes with the function of certain white blood cells, which are part of the innate immune system. Excessive alcohol consumption also weakens the body's immune defenses.⁶

The consequences of a weakened immune system

A flu-like infection is not necessarily a cause for concern. During the cold season, people in this country get an infection around twice, for example. Coming into contact with many people on public transport, at work, in public spaces, etc. can certainly push the immune system to its limits. Family size also plays a role, as does whether children attend daycare.

Children are sick more often than adults because of their immune system, which has not yet fully matured. The acquired part of the immune system matures around the age of ten and remains capable of learning throughout life.

As we age, however, the immune system loses some of its effectiveness, which is why older people are more susceptible to infections and more likely to develop cancer.

The course of the infection can sometimes also indicate whether the immune system is weakened. While an uncomplicated infection in people with a healthy immune system is harmless and heals quickly, people with an immunodeficiency may develop complications that can even be life-threatening.

Organs that are not typically affected by the disease may also become involved. In addition, those affected take longer to recover and often respond less effectively to antibiotic treatment.⁷

What are the signs of a weakened immune system?

Many people have a weakened immune system but do not notice it for a long time or misinterpret the signs. These signs may include:

• Constant fatigue
• Frequent colds
• Frequent gastrointestinal infections
• Being constantly under stress
• Poor wound healing
• Sudden development of a high fever
• Frequent muscle pain
• Skin problems, hair loss⁸

As we discussed in the previous chapter, the immune system is an interplay of a complex, multifaceted system. Testing every individual component for proper functioning would be very time-consuming.

Nevertheless, there are various examination methods that can reveal whether the immune system is not functioning as desired: a complete blood count, cellular immune status, and analysis of immunoglobulins.

The good news, however, is that we can do a great deal to strengthen our immune system. Sufficient sleep, exercise, a healthy diet, and an adequate supply of micronutrients all contribute significantly to effective immune defenses.

Conclusion

The proper functioning of our immune system is vital. If harmful substances and pathogens can no longer be adequately warded off, our well-being is impaired and we become susceptible to illness.

Nutritional deficiencies, chronic stress, and lack of sleep, among other factors, weaken our immune system. By maintaining a healthy lifestyle, we also do a great deal to strengthen our immune system.

Sources