Strengthening The Immune System. Studies And Tips

Our immune system protects us from bacteria, viruses, fungi, parasites, and helps to prevent infections. We often take our immune system for granted, but it can be weakened and needs special support, especially in challenging times.  

A weak immune system is more sensitive to diseases, аnd this is a strong enough argument for taking the necessary measures. The following article gives you an overview of how the immune system works and will help to understand the impressive work it does every day. 

You will also learn what is essential for a robust immune system and strengthen your body's resistance with simple tipsOf course, mental health should not be forgotten - please take note of the American Psychological Association's ten tips and strengthen your psychological resilience. Share the knowledge from this article with family, friends, elderly, and immunocompromised people - this is how we go through in challenging times healthy and together.

Man and his immune system

Our immune system is fascinating. It works continuously and protects us during healthy and especially unhealthy periods. The complex system can provide a significant survival advantage. The first observations on immunology were made already 400 years before our era. Diseases like plague, cholera, malaria, flu, or smallpox challenged humanity. Over time, researchers were able to figure out how a complex immune system works and what mechanisms work in the body.

The function of the immune system is to recognize and repel foreign structures. The human organism regularly interacts with the external environment. We absorb nutrients and excrete metabolic products. During this, many elements enter the body, which can make you sick. Our immune system is remarkably intelligent; it early identifies attackers and fights them [1].

The foreign elements are called antigenslike elements of bacteria, viruses, or other micro-organisms. If antigens are recognized and classified as dangerous, the immune response will be triggered. As a result, antibodies are generated in response to contact with antigens. Each antibody fits precisely to a specific antigen, according to the key-lock principle.

As a result, if antigens come into contact again, they will be quickly detected. The immune system is critical for our health and provides us with resistance to the external environment.

Our immune system works as follows: 

  • Detection of potentially harmful, foreign bodies, antigens
  •  Activation and mobilization of the immune system
  •  Attack on the antigen
  •  Control and termination of the attack

The body has many layers of protection.

  •  Physical barriers
  •  White blood cells
  •  Molecules (e.g., antibodies, complement proteins)
  •  Lymphatic organs

To better understand these layers of protection, Let's look at them separately in a more detailеd manner.

Physical barriers

These include skin, eye cornea, and mucous membranes, which covers the surface of internal organs. Besides, the body produces secretions, such as sweat or tear fluid, which contain antibacterial enzymes that additionally strengthen these barriers.

White blood cells

These are also known as leukocytes. These are cells of the immune system and are found throughout the body, including the blood and lymphatic system. 

These cells circulate in the bloodstream and penetrate the body tissue to look for foreign invaders and protecting against infectious disease.


 The following molecules are particularly relevant here:

  •  Cytokines
  •  Antibodies
  •  Complement proteins

These elements raise inflammation to prevent the spread of the virus. And other substances produced by the immune system help the body to heal the inflammation. While such processes are uncomfortable for us, they are a sign that the immune system is working.

Lymphatic organs

There are primary (primary) and secondary (peripheral) lymphatic organs.  Those play an essential role in the immune system.  The thymus and the bone marrow constitute the primary lymphatic organs. The primary lymphatic organs generate lymphocytes, one of the subtypes of a white blood cell in an immune system. The secondary lymphatic organs represent the location where the defense battles take place. Secondary lymphoid organs (SLOs) include lymph nodes, spleen, Peyer’s patches, and mucosal tissues such as the nasal-associated lymphoid tissue, adenoids, and tonsils.

The numerous components of the immune system play together to protect from foreign invaders.  This powerful system can save us from many diseases. That is why it is essential to take care of our bodies so that the immune system can do its critical work and act as a shield for us.

Strengthening the immune system

In times like these, a robust immune system is more important than ever. We have taken a closer look at the most essential and most useful tips for you:

  •  Sufficient sleep
  •  Movement and sport
  •  Sunlight and fresh air
  •  Stress reduction
  •  Balanced nutrition
  •  Drink enough

 Sufficient sleep

Studies show that sleep and the circadian system play a significant role in immunological processes.  Insufficient sleep leads to a stress reaction in the body and promotes the production of inflammatory cytokines. And this leads to immunodeficiency, which can harm health [3]. Therefore, make sure you sleep well and give your body enough rest to regenerate itself.  

Sport and activity

Data shows that there is a connection between health-promoting training and the general risk of disease. Moderate exercise has an anti-inflammatory effect. Sufficient exercise can thus improve defense activity and the immune system. Together with an adequate nutritional strategy, sport is a useful instrument to support the immune system. However, it should also be mentioned that too intensive training, for example, during competitions, can increase the risk of illness [4].

It is not necessary to be an athlete or to run a marathon. Even short walks can have a beneficial effect on the immune system. Therefore, to promote and maintain health, a minimum of 150 minutes (2.5 hours) of medium-intensity exercise per week is recommended [5].

Sunlight and fresh air

Vitamin D, also known as our “sun vitamin,” is produced under the sunlight. With insufficient sunlight exposure and, at the same time, inadequate intake of vitamin D through food can lower the effectiveness of the immune system [10]. Studies show that vitamin D can modulate the innate and adaptive immune response. Researchers have found a connection between a lack of vitamin D and an increased sensitivity to infections [6]. Therefore, especially during the winter months, care must be taken to get enough vitamin D over the diet. In cloudy and winter seasons, the intensity of sunlight decreases, and our body does not produce enough vitamin D. Since the amount of fat-soluble vitamin D in food is quite limited, it is recommended to take special supplements. Fish oil also contains a sufficient amount of vitamin D.

Stress reduction

Studies indicate a relationship between stress and a weakened immune system. Thus, the increased pressure can increase the risk of illness and intensify existing conditions [7]. The immune system is particularly vulnerable to stressful situations. If the immune system is already weak or you do not feel healthy, it is recommended to minimize stress. Relaxation procedures, such as yoga or meditation, can also help here.


Nutrition is one of the essential pillars in terms of strengthening the immune system. Many people have an increased lack of proper nutrients. With the help of a balanced diet, we can supply our immune system with essential components that are necessary for an effective immune response.

Researchers were able to confirm that vitamins and minerals play a crucial role in maintaining the immune system. Antioxidants also protect the immune cells and help keep their functionality [8]. Therefore, pay attention to a well-balanced diet with sufficient macro and micronutrients.


A balanced diet means coordinated intake of macronutrients:

  • 15 - 29% protein: You can find this in dairy products, beans, eggs, and meat.
  • Maximum 30% fats: Polyunsaturated fatty acids (PUFAs) are recommended here. You will find this mainly in vegetable oils.
  • 50-60% carbohydrates: Eat whole grains, vegetables, and fruits.


Vitamins and minerals are the two types of micronutrients. They play essential roles in human development and well-being, including the regulation of metabolism, heartbeat, cellular pH, and bone density.


We can say that all vitamins affect our immune system. However, the following vitamins contribute to the functioning of the immune system most.

  • Vitamin A 
  • Vitamin C 
  • Vitamin D 
  • Vitamin E

Vitamin A

Vitamin A keeps skin and mucous membranes healthful and helps maintain the barrier which protects against bacteria and pathogens. Vitamin A also increases the number and efficiency of the immune cells [1].

Sources of vitamin A: egg yolk, spinach, sweet potato, apricots, dairy products, and meat.

Vitamin C

It is an excellent antioxidant that inactivates harmful oxygen radicals and promotes immune defense by supporting various cellular functions of the immune system. Even a small lack of vitamin C leads to reduced production antibodies. In particular, smokers require two to three times more vitamin C than non-smokers, which is associated with the additional requirement of ascorbic acid, which is necessary for detoxification.

Sources of vitamin C: almost all types of fruit and vegetables, especially kiwi, passion fruit, citrus, berries, pomegranate, broccoli, cauliflower, tomatoes, spinach, and hot peppers

Interesting fact: Vitamin C is extremely sensitive to heat and light. That's why frozen vegetables, often have a higher vitamin content than fresh or cooked foods.

Vitamin D

Vitamin D plays a particularly important role in strengthening the immune system due to its antioxidant and anti-inflammatory qualities.  

Sources of vitamin D: fatty fish, veal, butter, milk products, eggs, mushrooms, avocados and cheese, and sunlight. However, food is a rather lousy source, which is why supplementation is recommended, especially in winter.

Vitamin E

Vitamin E is also an essential antioxidant with anti-inflammatory properties. It helps to lower the level of bad cholesterol that calcifies blood vessels. It also protects cells from damage caused by unstable molecules called free radicals.

Sources of vitamin E: nuts, such as almonds, peanuts, and hazelnuts, vegetable oils, such as sunflower, wheat germ, safflower, corn, and soybean oils.


Here too, all minerals are essential. However, the following are particularly important:

  • Zinc
  • Iron
  • Selenium
  • Copper
  • Calcium


Zinc is involved in many metabolic processes relevant to our immune system, protects against oxidative stress, and ensures that the number of immune cells remains constant. If zinc is missing, the immunological performance is weakened. Notably, older people, pregnant women, and very stressed people, usually have a zinc deficiency. But vegans should also pay attention to an adequate zinc intake since the bioavailability of zinc is particularly high in animal foods.

Sources of zinc: poppy seeds, sunflower seeds, oysters, seafood, beef and veal, nuts, dairy products (cheese).


Iron is essential for blood formation as well as for cell growth and energy supply. Iron deficiency can cause anemia, which causes increased susceptibility to infections.

Sources of iron: beef, fish, poultry, cereals, eggs, cabbage, citrus, tomatoes, milk.


The antioxidative and thus cell-protecting properties of selenium are also important for strengthening our immune system. Selenium also helps detoxify toxic heavy metals and harmonizes the immune system. A selenium deficiency causes a weakened immune response.

Sources of selenium: meat, fish, eggs, cereals, peas, lentils, asparagus, sunflower seeds, nuts (especially Brazil nuts).


Copper plays a vital role in blood and neurotransmitter formation. A deficit in red and white blood cells indicates a deficiency of copper.

Sources of copper: nuts, seeds, legumes, meat, and cereal products.


Calcium is closely related to the immunologically valuable vitamin C and is relevant for body cells and bones.

Sources of calcium: dairy products, figs, lentils, cabbage, parsley, beans, broccoli, spinach.

For the healthy functioning of the immune system, it is also recommended а a sufficient supply of phytochemicals and fibers. It is suggested that you include the following foods in your daily diet.

  •  Fish
  •  Green tea
  •  Coffee (in moderation)
  •  Garlic
  •  Linseed
  •  Lactic food
  •  Olive oil
  •  Red wine (in measure)
  •  Walnuts [10]

You should also drink enough fluid. Choose teas and water instead of lemonades or high-sugar drinks.

Tips from the team for supporting the immune system

What does the's team do to keep the immune system in good shape?

To answer this question, I asked my colleagues for you:

Nathaly, our professional, when it comes to online marketing, recommends a lot of exercise and sport - preferably in the fresh air. Also, she pays attention to a balanced and healthy diet with lots of fruits and vegetables. 

Nathaly's insider tip: a glass of freshly squeezed orange juice or lemon-ginger water for breakfast.

Our Sophia makes sure that to activate the body's defenses and boost the immune system, she gets enough sleep to avoid overreaction and drink enough. Of course, nutrition also plays an important role. To give the body the necessary nutrients, Sophia relies on an additional intake of vitamin C, zinc, and vitamin D3.

But our customer service team also has some insider tips when it comes to strengthening the immune system.

Our Susan relies on OPC (oligomeric procyanidins) to protect against free radicals. 

Her insider tip: a glass of turmeric latte in the evening. Mix some turmeric with pepper, cinnamon, cardamom, and honey with hot milk. The combination can also have a positive effect on the quality of sleep.

Maria's panacea is tea, tea, and tea again (unsweetened, of course)! Her tip for strengthening the immune system is to drink a lot, especially ginger tea. 

Maria's insider tip: integrate spices such as Curcuma or chili into your daily menu.

Mark, the herbalist in the team, attaches great importance to your mental health. A little yoga, pilates, reading, or meditation are a must for you to be able to relax holistically. He also relies on OPC and green smoothies. 

Mark's insider tip: "Gardening," spend a lot of time in the fresh air and benefit from your fruits and vegetables.

Alex uses humor as a miracle cure to strengthen the immune system.  His insider tip: good music. He provides us with good hits and makes the office laugh. Humor is known to be the best medicine.

We have already reached the next point, mental health. It is another crucial factor when it comes to the holistic strengthening of the immune system.

Mental health

In challenging times, mental health is more important than ever. Blows of fate, unusual situations, or crises are painful to process for many people.  Psycho-hygiene is particularly important in difficult times to strengthen the so-called “psychological immune system.” Strength and resilience determine how well people can cope with trauma or critical life events, such as job loss or illness [1]. The term "resilience" describes the psychological stability that helps us manage pressures. This resilience is based on social and personal resources, but can also be learned. Protective mechanisms perform protective actions both in childhood and in adulthood, allowing us to cope with stress without harming our health [9].

Numerous global crises have triggered scientists to research on that field. They tried to explain why some people deal with difficult times better than others. Therefore, the American Psychological Association describes the following ten ways to increase resilience, which should be used in difficult times:

  1.  Socialize
  2. Think of crises as manageable problems
  3.  Accept that changes are part of life.
  4.  Strive to achieve your goals
  5.  Decide to act
  6.  Look for ways to find yourself.
  7.  Promote a positive self-image
  8.  Take a sober look at the current circumstances.
  9.  Keep an optimistic expectation.
  10.  Take care of yourself.

Keep in touch with friends and family members. Thanks to digital media, this is already possible regardless of location. Social contacts strengthen resilience.   The sense of support and belonging is good. Crises and stressful events cannot be changed, but the reaction to them can.   Try to look beyond the present and look positively into the future. Acceptance can also help to focus on essential aspects again. Set new, realistic goals instead of focusing on unattainable or currently impossible goals.

Crises can contribute to self-development, еspecially after stressful situations, people report strengthened self-esteem. Don't let the critical events get the upper hand. Stay optimistic, take care of your needs and feelings, and make them seriously [9]. 

So especially in difficult times, do not forget about sufficient self-care, self-love, and joie de vivre. Together we can do everything!



 [1] Koch, R. (2019). Immune system - this is how I strengthen my bodyguard. 

 [2] Delves, P. (2019). Overview of the immune system.  

 [3] Besedovsky, L., Lange, T., Born, J. (2012). Sleep and immune function.  

 [4] Nieman, C. & Wentz, L. (2019). The compelling connection between physical activity and the body's defense system. 

 [5] Healthy Austria Fund. (2012). Austrian recommendations for healthy exercise.  

 [6] Aranow, C. (2012). Vitamin D and the Immune System.  

 [7] Morey, J. et al. Current Trends in Stress and Human Immune System.  

 [8] Marcos, A., Nova, E., Montero, A. Variations in the immune system are conditioned by nutrition. 

 [9] BZgA (2012). Resilience and psychological protective factors in adulthood. State of research on psychological protective factors of health in the majority. Federal Center for Health Education: Cologne.

 [10] Schmiedel, V. (2019). Nutrient therapy. Orthomolecular medicine in prevention, diagnostics, and treatment. Thieme: Stuttgart.

About the Author

Mirada Shwartz, BA, MA, studied health management, the topic of health is significant to her - both professionally and personally. Finding alternative, complementary methods for health promotion and prevention is particularly important to her. And this is how you came to the CBD - as a natural way of improving physical and mental health.

Mirada is coaching fitness, and a healthy lifestyle, to many users. As an author in our magazine, she is pleased to share all the knowledge and experience with you.

Leave a comment

All comments are moderated before being published