Immune system

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The immune system is the mechanism by which the body reacts against foreign molecules, considered “non-self”. It sets up two lines of defense and involves several organs. Throughout our lives, various factors can weaken or even disrupt it. But we can also act to maintain its optimal performance!

Title: The immune system: how does it work? How can we take care of it?

What is immunity?

Immunity is our body’s ability to defend itself against various external threats: viruses, bacteria, allergens… The immune system knows how to distinguish between “self” elements, i.e. those that belong to our body, and “non-self” elements that are not part of our body’s components, such as pathogens, or that are no longer part of it, such as damaged cells (these cells, which were originally “self”, become “non-self” and must be eliminated). It monitors our organism and when it perceives a threat, sets up the necessary defenses.

Which organs are involved in the immune system?

The immune system involves several organs, with different roles in the immune response. We distinguish:

– The primary lymphoid organs which correspond to the birthplace of immune cells: the bone marrow and the thymus,

– The secondary lymphoid organs: notably the lymph nodes, the spleen, the tonsils… where the immune reaction is organized.

What are the two types of immunity?

Two defense mechanisms made up of different types of cells make it possible to face the threats:

– Innate immunity: this first line of defense is the one we have at birth. Innate immunity is called “non-specific” because it reacts in the same way whatever the aggressor (pathogen / virus…). It offers a simple, almost immediate protection. It is made up of our natural barriers (skin, mucous membranes, secretions, microbiota) and an internal defense containing different types of cells, including monocytes and macrophages.

– adaptive immunity: this second line of defense is perfected throughout life in reaction to the aggressive agents encountered. It is said to be specific because it will trigger a reaction that depends on the “aggressor” (pathogen, virus…) that it will first recognize. It is therefore not a specificity due to the individual.

What can weaken the immune system?

> Stress ;

> Lifestyle; tobacco, alcohol, drugs;

> A poorly balanced diet in quality or quantity; a lack of activity or, on the contrary, too much physical activity;

> A lack of sleep;

> A disturbed environment: regular contact with toxic substances such as cleaning products, phytosanitary products, insecticides, etc. can disturb the immune system and also various pollutants found inside the home.

> The state of health: obesity, the existence of chronic pathologies, nutritional deficiencies, chemotherapies.

> extreme age: infants have a partially developed immune system, the elderly have a “tired” immune system.

What does a dysfunctional immune system look like?

The immune system can be dysregulated by excess or by default.

– A dysfunction by excess translates into a hypersensitivity of the immune system, i.e. an excessive response to pathogens. It can also lead to autoimmune diseases. This is an inappropriate reaction of the immune system that no longer recognizes the “self” and alters the body to the point of destroying cells of the “self”. Examples of such diseases include type 1 diabetes, lupus, Crohn’s disease, vitiligo…

– A default dysfunction is manifested by an insufficient reaction of the immune system to aggressors (viruses, microbes, parasites). This is called immunodeficiency. It can be innate (from birth) or acquired when it is caused by an external agent (anti-cancer treatment, immunosuppressive medication, HIV virus, etc.).

How to promote a good functioning of the immune system?

> Have a healthy lifestyle

Physical activity has an impact on immune responses. Regular moderate physical exercise stimulates the immune system, whereas a sedentary lifestyle or sometimes too much sports activity can lead to risks of immune deficiencies. A question of balance!

> Managing excessive stress

On the same principle, measured and controlled stress favors the circulation of white blood cells and the start of innate and adaptive immunity processes. On the other hand, when it is intense and continuous, stress can have harmful effects on the body and weaken the immune system.

> Adopt a varied and balanced diet

Micronutrients and vitamins contained in food are beneficial to the immune system. They participate in the inflammatory reaction of innate immunity, in the regulation of oxidative stress and enter into

the cellular metabolism of the adaptive immune reaction. They participate in the metabolism of the intestinal microbiota, which plays an important role in the immune system (60% of the individual’s immune cells are concentrated in the intestinal microbiota).

The diet can provide anti-oxidant factors: Vitamins A, C, E, Selenium, turmeric, polyphenols in green tea or red fruits. Some micronutrients participate in the inflammatory reaction: Zinc, Vitamin C, D, magnesium, selenium and intestinal permeability (Zinc, Vit D, Vit B6, molybdenum …)

> Preserve your immune capital with health solutions

In addition to a balanced diet, certain health solutions can improve immunity:

– dietary supplements based on microbiotic strains: the micro-organisms contained in probiotics have positive effects on health. They help maintain the intestinal microbiota in good health, or even reconstitute it if it is altered.

– vitamins A, C, D, B6, B9 and B12: they have been recognized by the European Food Safety Authority (EFSA) as contributing to the normal functioning of the immune system.

– Minerals, including magnesium and trace elements such as iron, zinc, copper and selenium.

– Plants: Echinacea has a natural ability to optimize immune defenses* and ginseng has shown, in vitro, its effectiveness against the flu virus and the respiratory syncytial virus responsible for bronchiolitis**.

– Propolis: manufactured by bees to seal the hive, this substance is recognized as having anti-inflammatory and anti-viral properties.

– Homeopathy: homeopathic therapy allows for the prescription of medications adapted to the immune reaction of each individual to an aggressor. By individualizing the prescription to the patient’s terrain, the homeopathic practitioner can optimize the action of homeopathic medicines. It is a personalized health solution that respects the body and its reactions.

*Catanzaro, M., Corsini, E., & Rosini, M. (2018). Immunomodulators inspired by Nature: A Review on Curcumin and Echinacea. Molécules, 23(11): 2778.

** Lee, J., Cho MK., M., & Hwange HS, H. (2014). Ginseng decreases lung disease in mice immunized with formalin-inactivated respiratory syncytial virus after challenge by modulating host immune responses. J Interferon Cytokine Res, 34(&&):902-14.