How to improve immune system to minimize the risk of infection

How to improve immune system? Or How to improve immunity? It’s a very common question of a health enthusiast mind, especially during a pandemic time. As the pandemic situation intensifies, you might be searching: how can I keep myself safe and healthy by improving the immune system? The answer is: it depends on you.

The Immune system is a defense system of the host body that protects from infections, illness and undesired responses. But when our defense system getting weak as we aged, which in turn contributes to more attack with our body easily by various types of microorganisms such as bacteria, fungi, and viruses like coronavirus and foreign substances like toxin. Thus, we have to improve the immune system naturally to minimize the risk of getting sick.

Remember that your healthy lifestyle is the indirect first-line defense system of your body. You may improve the immune system by following two ways:

  1. One way is to follow some good habits.
  2. Another way is to avoid some bad habits.

Rules to follow to improve immune system

1. Take Plant food-based diets

Nutrients may directly or indirectly influence immune cells triggering changes in their function or may exert effects through modifications in the gut microbiome. A bidirectional correlation among nutrition, immunity, and infection exists: alterations in one element affect the others. Studies have recognized that people who are malnourished and live in poverty are more at risk of infectious diseases.

Fruits, green vegetables, seeds, Herbs, Spices especially colorful vegetables and fruits are rich in antioxidants and nutrients. Whole plant foods like green vegetables like spinach, broccoli, fruits, herbs, mushrooms, nuts, seeds, spices, and legumes are also good options to improve the immune system that may give you protection against harmful pathogens.

The health benefits of plant food-based diets could be linked to both integrated antioxidant and anti-inflammatory mechanisms exerted by different phytochemicals with multi-factorial synergistic interactions present in fruit, green vegetables, herbs, seeds, and spices [1]. So, take more plant foods based diet for more nutrients and antioxidants.

2. Take more specific natural immunity booster foods

Specific natural immunity booster foods include garlic, ginger, turmeric, black seed, green tea, elderberry, and echinacea etc. that contain specific nutrients or compounds that play a role to boost immunity.

Garlic (Allium sativum) to increase immunity

Garlic is used as a traditional and herbal medicine for diseases such as microbial infections, cardiovascular diseases, and cancer. It contains various bioactive molecules that have the potential to influence immunity. Garlic can reduce the occurrence of the common cold by about 30% [2].

Immune cells, especially innate immune cells are responsible for the inflammation necessary to kill pathogens. Two innate lymphocytes, natural killer (NK) cells and gamma delta T cells (γδ-T) appear to be susceptible to diet modification [3]. Garlic (Allium sativum) has antiviral activity, but the responsible compounds have not been identified. Due to the high concentration of sulfur-containing compounds such as Allicin, Garlic shows immune-boosting properties. Generally, the order for antiviral activity was: ajoene > allicin > allyl methyl thiosulfinate > methyl allyl thiosulfinate [4].


It is used as traditional and herbal medicine to improve the immune system [5]. Ginger may help to reduce nausea. It has anti-oxidative stress, anti-cancer effects, and anti-diabetic effects, anti-inflammatory effects.

It is rich in phytochemicals includes components that scavenge free radicals formed in biological systems. By improving the antioxidant status ginger may improve the immune system that protects humans against many chronic diseases [6].


Turmeric contains a bright-yellow polyphenolic compound known as curcumin, which might enhance the function of the immune system [7]. Also, high concentrations of curcumin can help reduce exercise-induced muscle damage. Antimicrobial activities for curcumin and turmeric extract against microorganisms such as viruses, bacteria, fungi, and parasites have been reported [8].

Black seed (Nigella sativa)

Black seed is used as an ancient medicine to improve the immune system. Several studies demonstrated the black seed and its key active constituent, thymoquinone, to be effective pharmacologically against various illnesses including different chronic illness: mental and neurological illness, cardiovascular disorders, inflammatory conditions, infertility, diabetes, cancer as well as various infectious diseases by bacterial, viral, fungal and parasitic infections [9]. Extracts of N. sativa, as well as TQ (Thymoquinone) have a broad antimicrobial spectrum including Gram-negative, Gram-positive bacteria, viruses, parasites, Schistosoma and fungi [10].

Green tea

Both green and black tea contains flavonoids, a type of antioxidant. Also, green tea contains high levels of epigallocatechin gallate, (EGCG) another powerful antioxidant. EGCG has been shown to improve immune function. Green tea or its active components may have a preventive and therapeutic potential in dealing with T-cell-mediated autoimmune diseases [11]. Also, it improves immune cell functions and redox state [12]. Besides, green tea is a good source of the amino acid L-theanine that may help in the production of germ-fighting compounds in your T-cells.


Elderberry may reduce the symptoms of viral upper respiratory infections, but more research is needed. Black elderberry has been used to treat cold and flu symptoms, but there are no large-scale studies or meta-analyses [12]. Elderberry might beneficial to the immune system activation and in the inflammatory process in healthy individuals or patients with various diseases. It has an immunoprotective or immunostimulatory effect [13].


A study shows that echinacea helps to recover from colds slightly more quickly than those who received a placebo or no treatment [14]. Commonly, Echinacea is used to prevent and treat upper respiratory tract infection but this effect is clinically meaningful is debatable [15].

3. Vitamin and minerals to strengthen immunity

Vitamin A

It is involved in the improvement of the immune system [16] and shows regulatory roles in humoral immune processes and cellular immune responses. Vitamin A has demonstrated a therapeutic effect in the treatment of various infectious diseases [17, 18]. You may take vitamin A from natural sources or supplements. Best 27 Natural Sources of Vitamin A and Its Benefits, Daily Dose. 

Natural sources of vitamin A: Cantaloupe, Carrots, Pumpkin, Green leafy vegetables (such as spinach and broccoli), Red peppers, and Sweet potatoes, Dairy products, Eggs, Fortified cereals [16]

Example of Vitamin A supplements: Aquasol A Capsule, Arovit Vitamine A Tablet, and C-Mask Pack (Patch) etc.

Vitamin B6

Vitamin B6 improves immune system [16]. Animal and human studies recommend that vitamin B6 deficiency affects both cell-mediated and humoral immune responses [19]. A high dose of vitamin B6 supplement (such as 50 mg or 100 mg/day) could compensate for the lack of responsiveness of plasma pyridoxal phosphate (the active form of vitamin B₆) and further boost immune response of critically ill patients [20]. You may take vitamin B6 from natural sources or supplements.

Natural sources of Vitamin B6: Fruits (other than citrus), Potatoes, Salmon, Chickpeas, and Tuna [16].

Example of Vitamin B6 supplement: B-6 Caps 250mg, B6 250 Caplet, B6 Tablets, and B6 400mg Ctr Tab etc.

Vitamin C

Vitamin C helps to form your immune system [16]. By receiving 1g – 2g of vitamin C per day reduced the duration of colds by 14% in children and 8% in adults. It is thought to rise the production of white blood cells or improve the function of certain white blood cells which are important to fight with infections [21]. Vitamin C can help to maintain healthy skin that provides a first-line barrier to microorganisms. You may take vitamin C from natural sources or supplements.

Natural sources of Vitamin C: Citrus fruits (such as oranges and grapefruit), Broccoli, sprouts, Cantaloupe, Brussels, Kiwifruit, Strawberries, Peppers, and Tomatoes [16].

Examples of Vitamin C supplement: Ascor, Acerotab, Acti-scorb 500 Caplet, Ascorbic Acid Powder, and Aromacura Shower Filter etc.

Vitamin D

Vitamin D helps to improve your immune system [16]. Its deficiency may raise your chances of getting sick like an acute respiratory infection [22]. Vitamin D has a mild protective effect against respiratory tract infections in most people, but provide a protective effect in those who had a very deficiency of Vitamin D [23, 24]. You may take vitamin D from natural sources or supplements.

Natural sources of Vitamin D: Eggs, Fish (such as herring, salmon, mackerel, trout, and tuna), Fish liver oil, cod liver oil, fortified cereals, fortified margarine, fortified dairy products, fortified orange juice, mushroom, and fortified soy beverages (soymilk) [16].

Example of Vitamin D supplement: Ostoforte capsule, D Caps, Theraplex D Tab, and Vitamine D tablet etc.

Vitamin E

It is a potent antioxidant and can improve the host immune system [16]. Vitamin E induces a higher differentiation of immature T cells through increased positive selection by thymic epithelial cells, which results in the enhancement of reduced cellular immunity in the aged [25]. Its Immunomodulatory effects have been observed in animal and human models under disease and normal conditions [26]. You may take vitamin E from natural sources or supplements.

Natural sources of Vitamin E: nuts and seeds fortified cereals and juices, green vegetables (such as spinach and broccoli), peanuts and peanut butter, and vegetable oils.

Example of Vitamin E supplement: Acti-copherols 200 Cap, E 400 IU, and E 200 Cap Natural 200 unit.


Iron is an essential element for the regular development of immunity [16]. Its deficiency affects the capacity to have a sufficient immune response. Iron is essential for immune cell proliferation and maturation, principally lymphocytes, linked with the generation of a specific response to infection. Our body can decrease the iron availability to be consumed by infectious elements, by proteins such as transferrin and lactoferrin. The bacteriostatic mechanisms of the immune system reduce the availability of the metal, interfering with bacterial growth. Besides, the immune system uses iron as the intermediary in the production of bacteriostatic cells [27, 28].

Also, iron is needed for the proliferation of parasites, bacteria, and neoplastic cells. Thus, additional iron in our body could potentially facilitate the development of infections and the invasion of tumoral cells. You may take Iron from natural sources or supplements.

Natural sources of Iron: Beans, Eggs, Fruits (such as raisins and prunes), Green vegetables (for example spinach, broccoli, kale, and collard greens), Meat, Organ meats (such as liver), Peas, Nuts, Seeds, Poultry, Seafood (for example tuna, sardines, haddock, shrimp, and oysters), Soy products (such as tofu), Whole grain, enriched, and fortified breads, pasta, cereals, and rice etc.

Examples of the iron supplement: Dexiron, Venofer, Infufer, Iron Chews, Monoferric, Fe-chelate Tab, and Iron Chelate 25 mg.


Magnesium has a strong link with the immune system [16], in both nonspecific and specific immune response, also called as innate and acquired immune response [29]. You may take Magnesium from natural sources or supplements.

Natural sources of Magnesium: avocados, beans, peas, green leafy vegetables (such as spinach), fruits (such as bananas and raisins), dairy products, nuts and pumpkin seeds, whole grains, and potatoes etc.

Example of Magnesium supplement: Acti Mag 250 Caplet, Chelated Magnesium 150 mg – Tab, Magnelis, and Chelazome Magnesium 100 mg.


Selenium is a potent antioxidant and may improve immune system [16]. Dietary selenium is a vital micronutrient that affects various aspects of human health, including optimal immune responses [30]. You may take Selenium from natural sources or supplements.

Natural sources of Selenium: eggs, enriched pasta and rice, whole grains, meats, nuts (such as Brazil nuts) and seeds, poultry, and seafood

Example of Selenium supplement: Bio Selenium Tab 50 mcg, Davinci Selenium Tab 50mcg, and Selenium 100 – Caplet etc.


People who have a deficiency of zinc are more susceptible to cold, flu, and other viral infection. Zinc (more than 75 mg of zinc per day) can reduce the duration of the common cold by an average of 33% [31]. You may take Zinc from natural sources or supplements.

Natural sources of Zinc are Beans, peas, Beef, Dairy products, Nuts, Fortified cereals, Seafood (such as clams, crabs, lobsters, oysters) Poultry and Whole grains etc [16].

Example of Zinc supplement: Zin Pro Tab, Acti-ZN 25 Caplet, Chelated Zinc Tablets, Fisherman’s Friend Zinc Lozenges, Halls Zinc Defense, and Zinc Sulfate Tablet etc.

3. Eat healthy protein and fat

Protein is the main building block for immune cells and antibodies. They play a key role in helping our body’s immune functions. Protein comes from both animal and plant-based sources. Animal sources include fish, poultry, beef, milk, yogurt, eggs, and cottage cheese as well as plant sources include nuts, seeds, beans, and lentils.

Healthy fats like those found in olive oil and salmon may boost your immune system to fight with pathogens by decreasing inflammation. Omega-3 fatty acids, such as those in chia seeds and salmon fight inflammation [32]. A study shows that olive oil is linked to a decreased risk of chronic diseases like heart disease and type 2 diabetes and helps your body to fight with harmful disease-causing bacteria and viruses by its anti-inflammatory properties [33].

4. Take probiotics or probiotic-containing foods or probiotic supplement

Probiotics are live beneficiary microorganisms which, when administered in sufficient amounts, offers health benefits on the host. If you want to know about Probiotic you may read:

Deregulation of the gut microbiota results in various pathological disorders such as diabetes, inflammation, cancer, dyslipidemia etc [34]. A well-balanced gut microbiota, or Gut flora or gastrointestinal microbiota by probiotics can improve health and prevent or treat diseases [35]. Probiotic bacteria have significant effects on the functionality of the mucosal and systemic immune systems through the activation of multiple immune mechanisms [36].

However, natural probiotics such as yogurt, probiotic fermented milk, Miso Soup, Kefir, Kombucha, and Cultured Vegetables (such as Sauerkraut and Kimchi) you may take regularly to maintain well-balanced gut flora. Also, you may take a probiotic supplement such as Zelac Probiotic Support, Flora Q, Prodigen, Probichew Probiotic Support, manufactured by the pharmaceutical company.

5. Moderate Exercise regularly to boost your immunity

Moderate exercise is good for the immune system and vigorous exercise increase susceptibility to infections [37]. Regular physical activity reduces the occurrence of several chronic diseases including non-communicable diseases such as chronic inflammatory disorders and cancer as well as communicable diseases such as viral and bacterial infections [38, 39]. Studies also show that a physically active lifestyle lessens the risk of communicable diseases including viral and bacterial infections [40-46]. Undeniably, acute forceful exercise has a profound effect on the capacity of the immune function. Certainly, the behavior of almost all immune cell populations in the bloodstream is altered in some way during and after exercise [46,47].


6. Stay well hydrated to boost your immunity

Water is a very crucial chemical component of our body and makes up about 60% of our body weight. A well-hydrated state is required to improve immune system. According to the National Academies of Sciences, Engineering, and Medicine determined that adequate daily fluid intake is:

For men: about 15.5 cups (3.7 liters) of fluids

For women: about 11.5 cups (2.7 liters) of fluids a day

Here, fluids include water, other beverages and fluid from food.

7. Get enough sleep to strengthen your immunity

Bidirectionally sleep and immunity is linked. Immune system activation alters sleep, and sleep in turn affects the innate and adaptive immunity. Microbial challenges stimulate the immune system which triggers an inflammatory response that can induce an increase in the duration of sleep and intensity, but also a disruption of sleep. During an infection enhancement of sleep is supposed to feedback to the immune system to stimulate host defense [47].

Short sleep duration and poor sleep may increase the susceptibility to the common cold [48]. Poor sleep continuity and short sleep duration (less than 6 or 7 hours per night) are linked with the onset and development of several chronic illnesses [49-52], susceptibility to severe infectious illness [53-55], and premature mortality [56].

Proper sleeping time according to the American Academy of Sleep Medicine and the Sleep Research Society is:

Age GroupSuggested Hours of Sleep Per Day [57, 58]
4-12 months (Infant)12-16 hours per day (including naps)
1-2 years (Toddler)11-14 hours per day (including naps)
3-5 years (Pre-school)10-13 hours per day (including naps)
6-12 years (School Age)9-12 hours per day
13-18 years (Teen)8-10 hours per day
18-60 years (Adult)7 or more hours per night

8. Practice good Hygiene

Practicing good hygiene is crucial for preventing infection.

  1. Frequently and thoroughly wash your hands with soap and running water at least 20 seconds so that kills microbes like bacteria, viruses that may be on your hands.
  2. or thoroughly clean your hands with an alcohol-based hand rub such as hand sanitizer gel or 70% isopropyl alcohol solutions.
  3. Avoid touching, eyes, nose, mouth, and face with unwashed hands.
  4. Wash your hand:
  • After coughing or sneezing
  • When caring for the sick
  • After the toilet when hands are visibly dirty
  • Before eating.
  • After touching other people.
  • Before, during and after handling raw and cooked food
  • After handling animals or animal products or animal wasted

9. Psychological practice

a. Good Social relation

Build a proper social relationship with your trusted family, friends and neighbor.

b. Have a Laugh

Laughter is an effective psychological medicine. It may reduce stress and increase immune cell activity such as increase natural killer cells (also known as NK cells, killer cells, and K cells) activity [59].

c. Think positive

When you think positively, your body’s immune system works well.

Avoid some bad habits to improve the immune system

1. Avoid your stress. Our mind and body are closely linked. A wide variety of diseases including stomach upset, acidity, hives, and even heart disease, are linked to your emotional stress [60]. Long-term stress promotes inflammation, as well as imbalances in immune cell function [61]. Manage your stress by religious practice, meditation, exercise, yoga, and other mindfulness practices.

2. Quit Smoking. Smokers have an increased risk of catching infections and suffering severe complications from those infections [62].

3. Avoid body overweight by maintaining exercise and diets.

4. Don’t take harmful and unsafe alcohol. If you drink alcohol, drink only in moderation. Alcohol misuse can also weaken your immune system. Quit taking alcohol if you can.

5. Avoid carbonated drinks or fizzy drinks.

6. Cut extra sugars for your food menu.

7. Avoid junk food.


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