Originally published on World Council for Health.

Natural immunity is our body’s natural system of protection against micro-organisms including bacteria, parasites, and viruses. We can protect ourselves against any number of pathogens including the virus that causes Covid-19.

This guide provides a basic outline of the immune system and an introduction to optimizing immune function through food, lifestyle choices, herbs, and supplements.

The immune system

The immune system is a multi layered shield for the body. It includes many types of cells that work together to fight infection and protect against disease. These cells identify, mark, and destroy pathogens.

The organs and tissues of the immune system are found throughout the body: 

• Skin and mucous membranes
• Lymph nodes and lymphatic vessels
• Spleen
• Thymus
• Bone marrow
• Tonsils and adenoids

The immune system produces specialized proteins called antibodies that have several key roles in protective immunity and in response to infection.

A well-functioning immune system is crucial for staying healthy. There is a considerable volume of science demonstrating how dietary and lifestyle choices, as well as certain food supplements and herbs, can support the immune system. Therefore, the potential of natural substances to strengthen the immune system has long been the subject of investigation, and this is supported by traditional knowledge in terms of the use of herbs.

We now know that optimal immune function requires optimal nutrition and that exercise, stress, sleep, and natural light exposure also play a critical role.

The food we eat

The immune system is not able to function optimally when basic nutrients are lacking. 

It is important to eat a balanced diet and to limit consumption of processed foods and refined sugars because they are devoid of nutrients. It’s also better to buy the ingredients and freshly prepare food, because levels of vitamins and other micro-nutrients are reduced by cooking methods and storage.

Proteins and amino acids are needed for antibody production and normal immune function along with vitamins A, B, C, D, E; minerals including zinc, iron, selenium, magnesium; and essential fatty acids.

Fruits and vegetables are natural immunity superfoods and contain natural plant chemicals such as flavonoids. A higher intake of fruits and vegetables leads to a reduction in inflammation and enhancement of immunity, as shown in a systematic review and meta analysis of 83 studies. 

Apples, citrus fruits, blueberries, onions, broccoli, kale, tomatoes, green tea, other teas, cacao, whole grains, and certain herbs and spices including thyme and turmeric are flavonoid rich foods. Flavonoids and a soluble fibre called beta-glucans help to reduce inflammation and regulate the immune system.

Oats, barley, and mushrooms are beta-glucans, as research shows. The beneficial effects of β-glucan-containing mushrooms have been long known and are traditionally utilized in Oriental medicine for strengthening the body’s immune system. Examples are the Shiitake (Lentinus edodes) of Japanese origin and Lingzhi (Ganoderma lucidum), used in Chinese medicine.

Kefir, live natural yoghurt, kombucha, and sauerkraut are probiotic foods that help to support optimal immune function by improving gut function and via immune modulation.

Exercise is good

Regular exercise, research shows, is essential for maintaining a healthy immune system and countering the effects of aging on immune function.

Exercise strengthens the body’s ability to fight off infection. Regularly engaging in moderate exercise is beneficial for immune defense. Notably, older adults and those with chronic disease benefit significantly with movement and regular exercise. 

Learn more about the ways exercise affects immunity here. 

Rest is best

Sleep and the biological clock, the circadian rhythm, have a significant influence on immune function. Diet and lifestyle help to regulate the biological clock and promote healthy sleep via the production of melatonin.

Soak up the sun

Sunlight enables the production of vitamin D—the sunshine vitamin, in the skin. A major cause of vitamin D deficiency is inadequate exposure to sunlight. However, vitamin D is available in some foods naturally—fish liver oil and fatty fish, and fortified milk products, orange juice, and breakfast cereals. An estimated 50% of people worldwide are vitamin D deficient.

Supplements are key

Vitamin C, vitamin D, and Zinc have been widely researched and used for natural immune support and optimization for years. 

Vitamins A, E and B complex, essential fatty acids, selenium, magnesium, iron and copper, beta-glucans, and flavonoids and a good quality multivitamin and mineral are especially important when diet is not ideal.

Probiotics can also be supplemented.

A cup of tea

Herbal remedies and teas such as green tea, mint tea, white pine needle tea, echinacea, and pelargonium can be taken to support and balance the immune system. They can also be used at the first signs of illness, such as a sore throat.

Learn more about the effects of botanical drugs and supplements on the immune system. 

Elderberry has traditionally been used in reducing the duration of colds and flu. 

Chronic stress has been shown to suppress immunity

Adaptogens are a class of herbs that include licorice, astragalus and ashwagandha. They have the unique ability to improve an individual’s ability to cope with stress by promoting the ability to adapt and therefore protect against all types of stressors including physical, emotional, chemical, and biological. 

These herbs can directly modify the immune system, stabilize various physical functions, and bring things back into balance when taken in times of increased stress. They normalize the physiological process of the body and help the body adapt to change. 

Astragalus is a Chinese herb that has been used over centuries for general immune support. It has anti-inflammatory, antibacterial, and antiviral properties.

Licorice is a well-known herbal medicine used worldwide over thousands of years. Accumulating evidence has shown its potential to balance the immune system. It also has natural antiviral and anti-inflammatory properties. 

Stress free is the way to be

The immune system responds to the stress of challenging circumstances. Chronic stress can lead to increased inflammation in the body and is associated with activation of latent viruses. This explains the re-activation of cold sores (caused by the herpes virus) during times of stress.

Every person manages stress differently. Some are more able to adapt and cope with chronic stress than others. Mindset, frequency of exercise, and social support systems all have important roles to play. Certain activities, such as yoga, mindfulness and swimming, are particularly linked to improved adaption to stress. It is also known that certain nutrients are depleted by stress, and therefore those with poor nutritional status are likely to fair worse.  

It’s time to optimize your immune system

Eating healthy foods, getting plenty of sleep, exercising regularly, keeping stress levels low, and supplementing appropriately keep our immune systems supported and ready to fend off a host pathogens, including the virus that causes Covid-19.

It’s a blessing that your body can build its defenses against infection and create a harmony with nature without being directed by expensive pharmaceuticals. You are gifted with an amazing natural immune system that can be optimized to its full potential using the tools presented here.

If you or someone you know is seeking to support their immune system due to infection with the virus that causes Covid-19, we recommend our Early Treatment Guide.