Our immune systems do a great job of fighting against foreign organisms such as viruses and bacteria, parasites, fungi as well as cancer cells to protect us from illness and help us keep healthy.
Several factors play their role, such as age and diet which decide how strong this defense system will be.
When global pandemic outbreaks occur such as the COVID-19 outbreak, we extra concerned than usual about staying healthy and strong.
In the case of COVID-19, our immune systems need to be strong and adapt unaided to COVID-19 until a vaccine is in our hands.
What are the parts of the immune system?
It’s a system of cells, organs, and proteins that work together to protects our bodies.
Especially white blood cells (leukocytes) play a vital role in the immune system.
What are the organs of the immune system?
The organs of the immune system are called lymphoid/lymphatic organs.
- Primary lymphoid organs: Bone marrow and thymus.
- Secondary lymphoid organs: Spleen, lymph nodes, tonsils, and specialized tissues in the mucous membranes of the bowel.
What are the important types of white blood cells (immunity cells)?
The specialized cells that are the parts of the immune system provide the body protection against disease. This protection is called immunity.
The important types of white blood cells are:
Phagocytes are the cells that eat up and inactivate invading organisms, such as eosinophils, neutrophils, macrophages, monocytes, and dendritic cells.
When someone gets a bacterial infection, there will be an increase in the number of a type of phagocytes called “neutrophils” in the blood. That’s why the blood test is important to confirm the bacterial infection.
Lymphocytes (T, B):
Lymphocytes (T, B) help to destroy foreign organisms(viruses, bacteria) and help the body to remember the foreign invader organisms to catch them quickly when they invade again.
To be specific,
- B lymphocytes: They work as military intelligence like ISI, CIA, MSS, or M1-6. They find foreign organisms and guide the soldiers (T lymphocytes).
- T lymphocytes: They destroy foreign organisms that military intelligence finds. T cells are also known as killer cells. T cells also help signal other cells such s phagocytes to do their jobs.
What are the main immune proteins?
- Antibodies: Help T cells to kill antigens by attaching on antigen surface, neutralize toxins produced by different organisms, activate complement proteins.
- Complement proteins: Complement proteins help to kill bacteria, viruses, or infected cells.
How does the immune system work?
Our body detects new foreign substances such as antigens, the immune system catches the antigens and removes them from the body.
B lymphocytes are activated and produce plasma cells and memory B cells. Plasma cells make antibodies. These antibodies are specialized proteins that stick to specific antigens.
Antibodies can’t destroy antigens without help, they just can find antigens and stick them onto antigens. The destroying is the job of T lymphocytes. T lymphocytes destroy antigens labeled/flagged by antibodies or cells that are infected or somehow changed(cancer cell).
The antibodies stay in the body as well as memory cells of the body have all the information of the antigen that attacked the body once.
If the immune system comes across that specific antigen again, the antibodies are always there ready to do their job. That’s the reason if someone gets sick with a disease, such as chickenpox, usually won’t get sick from it again.
How does a vaccine work?
When a vaccine having antigen/attenuated organism is introduced in the body in a way that doesn’t make a person sick, but it let the body make antibodies that will protect the person from future attack by that specific foreign organism.
What are the types of immunity?
There are three types of immunity present in humans, such as innate, adaptive, and passive immunity.
1. Innate immunity (Nonspecific):
Everyone is born with a type of general protection called natural or innate immunity. The innate immune system identifies and eliminates pathogens that might cause infection.
It involves an antigen-independent mechanism that offers the primary defense against pathogens.
Anatomical and physiological barriers, inflammation, phagocytosis, and the complement system are the main parts of innate immunity.
What are the anatomical and physiological barriers?
Anatomical and physiological barriers are barriers that exclude many microbes, such as skin, eyes, respiratory tract, digestive tract, and genitourinary tract.
For example, The skin stops foreign organisms from entering the body.
Innate immunity cells:
The innate leukocytes include natural mast cells, killer cells, basophils, eosinophils, and phagocytic cells (macrophages, neutrophils, and dendritic cells).
2. Adaptive immunity (antigen-specific):
Adaptive immunity develops throughout life also know as active, specific, and acquired immunity.
Adaptive immunity is developed only when we are exposed to diseases or when we are immunized against them with vaccines.
Adaptive immunity results from random recombination of immune globulin and T lymphocyte receptor genes within lymphocytes and selection by antigen-dependent activation, proliferation, and differentiation of those cells to resolve or manage the infection.
T lymphocytes B lymphocytes (plasma cells, memory cells) and antibodies (immunoglobulin) are the main parts of adaptive immunity.
3. Passive immunity:
Passive immunity is an immunity that is not produced through someone’s own immune system.
It is also known as borrowed immunity that is provided by another source.
- Transferring of antibodies from mother to fetus through the placenta.
- Antibodies in a mother’s breast milk give a baby temporary immunity.
- When someone has a disease, he/she can get passive immunity through antibody-containing blood products such as immune globulin (antibodies).
- Antibodies(immunoglobulin) collected from the blood of recovered coronavirus patients protect against COVID-19 and strengthens the immune system.
Passive immunity provides immediate protection from a specific disease but it lasts for a short time (a few weeks or months).
What’s the difference between active and passive immunity?
|Adaptive immunity||Passive immunity|
|Someone naturally produces his own immunity.||It is not someone’s own immunity. It is borrowed from someone else or synthesized in the lab.|
|Active immunity takes time to develop (usually several weeks). So, protection is not immediate.||Protection is immediate.|
|Active immunity is long-lasting.
|Passive immunity is not long-lasting, it lasts only for a few weeks or months.|
How to boost our immunity?
Our bodies make new cells and proteins such as antibodies to fight against infection and abnormal cells. Our immune system is always ON even we are sleeping.
Our mental and physical health both have a huge effect on this fight.
What are the factors that affect our immune system?
Almost all kinds of factors can affect our immune systems, such as:
- Lifestyle-stressful lifestyle
- Sleep-poor sleeping pattern
- Diet-lacking in essential nutrients
These factors can fail our system, and ultimately our body can be defeated by infection and abnormal cells.
We can boost, sustain, or support our immunity by adopting a healthy lifestyle, quality sleeping, good diet.
1. Focus on healthy diet-essential nutrients
Many nutrients are involved in boosting the immune system.
We can get these nutrients from a wide variety of fruits, vegetables, whole grains, and protein-rich foods.
- Fruits and vegetables:
A study was conducted between 2 groups. 1st group served with greater than five and 2nd group served less than two fruits and vegetables. The 1st group with higher fruit utilization had a stronger immune response to pneumonia.
The main parts of the immune system such as antibodies and immune system cells depend on proteins.
Protein is essential to build and repair body tissue and fight against viral and bacterial infections.
Protein-calorie malnutrition impairs and weakens the immunity with particularly harmful effects on the T-cell system. It increases opportunistic infection and increases morbidity and mortality in hospitalized patients.
Other effects of too little intake of protein in the diet include weakness, fatigue, apathy, and poor immunity.
Sources of protein:
We can get protein from lean beef, chicken, and turkey, eggs, beans, and soy-based food.
Zinc is an essential mineral that helps white blood cells against infections.
Zinc deficiency impairs the immune system and makes people more susceptible to cold, flu, and other viruses. The studies showed the severity and duration of the common cold reduced by an average of 33% in the people who have enough zinc.
Sources of zinc: fish, shellfish, beef, dark meat chicken, turkey, dairy products(cheese, milk, low-fat yogurt), eggs, whole grains, legumes, nuts, seeds, mushrooms, kale, soy-based foods.
- Omega-3 fatty acids:
Help the immune system in different ways. DHA-rich and EPA-rich fish oil increases immune B cell activity (a white blood cell).
Sources of omega-3 fatty acids: salmon, tuna, mackerel, walnuts, flaxseed, and chia seeds.
- Vitamin D:
Vitamin D can regulate both innate and adaptive immune responses. Multiple studies have indicated that deficiency in vitamin D can cause dysregulation in immune responses and it is associated with increased susceptibility to infections as well as increased autoimmunity (autoimmune diseases).
We can get vitamin D from three sources:
- nutritional sources
- UVB-dependent endogenous production
Nutritional sources of vitamin D: salmon, mackerel, egg yolks, fortified foods (milk, No sugar added orange juice, mushrooms, tofu, soy beverages, grains& rice, whole grain cereals-whole grain bread).
- Antioxidant-rich foods: citrus, grapes, blueberries, cranberries, apples, dark chocolate, papaya, cantaloupe, tea, mushroom, broccoli, spinach, carrots, bell, peppers, sweet potatoes, asparagus, onions, and beets.
These foods have Vitamin A, C, and E that have antioxidant effects.
Antioxidant-rich foods to be specific:
Vitamin A plays a vital role in the development of the immune system (innate and adaptive) and regulation in cellular and humoral immune processes.
Vitamin A has been indicated as a therapeutic (clinical) effect in the treatment of several infectious diseases.
Vitamin A deficiency increases morbidity and mortality during infectious diseases. In multiple clinical tests, vitamin A supplementation increased immunity in children of developing countries.
A study was conducted on preschool-age rural Indonesian children. Children with mild night blindness and children with normal eyes during the same study interval, developed the respiratory disease, and diarrhea many times. The respiratory disease and diarrhea both were more closely related to vitamin A deficiency. These consequences may elucidate much morbidity and mortality that recently reported for vitamin A-deficient children.
How does vitamin A deficiency disables both innate immunity and adaptive immunity?
Vitamin A deficiency disables innate immunity by
- preventing the usual regeneration of mucosal barriers spoiled by infection
- reducing the function of macrophages, neutrophils, and natural killer cells
Vitamin A deficiency disables adaptive immunity by reducing
- Th2 cells directed antibody-mediated reactions
- few feature of Th1-mediated immunity
Vitamin A deficiency causes problems in the regeneration of mucosal epithelial and immune function that increase mortality in infants, young children, and pregnant women.
Sources of vitamin A and beta-carotene: liver, cod-liver oil, butter, eggs, and dairy, pumpkin, squash, carrots, spinach, sweet potatoes, cantaloupes, dark leafy greens, orange, and mangoes.
Vitamin C is a great antioxidant that strengthens immune defense by supporting and promoting various cellular functions of both the innate and adaptive immune systems.
The vitamin C boosts immunity by:
- activating of phagocytes ( phagocytes eat up viruses, bacteria, and other particles).
- promoting the growth and spread of lymphocytes that increase antibodies.
During infection and stress, the concentrations of vitamin C in the plasma and leukocytes quickly decrease. Studies show that supplementation vitamin C improves the work of the immune system by increasing activities of the antimicrobial and natural killer cells, lymphocyte proliferation, chemotaxis, and delayed-type hypersensitivity.
Vitamin C is familiar to prevent the common cold. Vitamin C helps in maintaining healthy skin which works as a barrier to foreign harmful viruses and bacteria.
Sources of vitamin C: citrus fruits, strawberries, kiwifruit, green and red bell peppers, cauliflower, broccoli, tomatoes, sweet potatoes, asparagus, and brussels sprouts.
Vitamin E is a lipid-soluble antioxidant. It is present in higher collection in immune cells compared to other cells in the blood. It is one of the most functional nutrients known to modulate immune function.
Directly modulation of immune function: Vitamin E modulates T cell function through directly influencing T cell membrane integrity, signal transduction, cell division, and differentiation of immature T cells in the thymus.
Indirectly modulation of immune function: Vitamin E also modulates immune functions indirectly by affecting inflammatory mediators generated from other immune cells.
Vitamin E deficiency impairs normal functions of the immune system, which may lead to infectious diseases such as respiratory infections and allergic diseases such as asthma.
supplementation of vitamin E enhances the function of the immune system and reduces the risk of infections and allergic diseases.
Studies found that the decreased cellular immunity with aging or during the development of AIDS was significantly improved by having a vitamin E-rich diet.
Sources of vitamin E: nuts, almonds, walnuts, pine nuts, vegetable oil, hazelnut & hazelnut oil, whole grains, corn, sunflower, abalone, wheat germ, palm, cottonseeds, mamey sapote, yams, and sweet potatoes.
Selenium is important for initiating, maintaining, immunity, and regulating excessive immune responses (development and expression of nonspecific, humoral, and cell-mediated).
Selenium is also important for the optimal functioning of neutrophils, macrophages, NK cells, T lymphocytes, and some other immune mechanisms.
Selenium boosts the immune system including aging immunity or protection against specific pathogens.
Sources of selenium: salmon fish, haddock fish, Brazil nuts, beef, chicken, turkey, eggs, cottage cheese, mushroom, brown rice, sunflower seeds.
- Probiotic & Prebiotics:
Probiotics are the live helpful bacteria that are normally originated by the procedure of fermentation in food.
Probiotics improve gut health and immunity.
Studies showed that probiotics have therapeutic capabilities for diseases, including several immune response-related diseases, such as eczema allergy, viral infection, and enhancing vaccination responses.
Sources of probiotics: yogurt, kefir, sauerkraut, tempeh, miso soup, kimchi, kombucha, pickles, traditional buttermilk, acidophilus milk, natto, soft cheeses, sourdough bread, supplements.
Prebiotics are the fuel that is important for the feed and nourishment of probiotics.
Prebiotics are the are non-digestible components of foods. Prebiotics fiber moves through the small intestine, remains undigested. When it reaches the large colon, It is fermented.
Prebiotics directly stimulate the immune system or indirectly affect by increasing the population of beneficial or helpful microbes or probiotics.
Sources of prebiotic: onions, garlic, bananas, the skin of apples, grapefruit, watermelon, Jerusalem artichoke, dandelion green, leeks, asparagus, wheat bran, barley, oat, konjac root, cocoa, chicory root, burdock root, yacon root, jicama root, seaweed, savoy cabbage, chickpeas, lentils, beans, kidney beans, baked beans, soybeans, almond, pistachio, and flaxseeds.
2. Supplement carefully:
If vitamin A, C, D, E, selenium, omega 3 fatty acids, or probiotics & prebiotics are not available in diet form or not enough or you need any of them in an emergency you can buy in supplement form.
Turmeric is a spice commonly used in Asian cuisine and traditional medicine for centuries.
Turmeric contains a compound called curcumin.
Research shows that curcumin improves immune function.
Low doses of curcumin also enhance antibody responses.
Several in vivo and in vitro studies have shown that curcumin is active against a variety of viruses, bacteria, and fungi, including highly pathogenic, emerging, and multi-drug resistant strains.
Taking turmeric or curcumin supplements even in high doses causes no harm.
If you have any medical conditions, such as if you take blood thinners, check with your doctor before supplementing with curcumin.
Garlic contains various compounds that have many beneficial effects with promoting immunity, antimicrobial and antiviral properties that relieve the common cold.
A study showed that garlic may prevent incidences of the common cold.
The study suggested that supplementation of aged garlic extract may boost immune cell function and may be partially managed to reduce the severity of common colds and flu.
Echinacea is used in herbal medicine that helps to control symptoms of colds, influenza, infections, and other various diseases. Echinacea is a popular traditional medicine in North America.
A trial found that echinacea may have a mild protective effect against upper-respiratory infections.
It’s safe to take echinacea for a short period. If you are at high risk, you may consider taking it over the next few weeks.
5. Stay properly hydrated:
Dehydration can impair body functions including immune function.
Dehydration is linked with gastrointestinal, urological, circulatory, and neurological
disorders. Proper circulation is really important for immune cells and antibodies
movement to reach immune organs or target areas.
Hydration will help bodily functions work properly, flush out the toxins from the body and
lower the chances of flu.
Other alternatives to water include fruit juices made of citrus fruits and coconut water.
6. Quality sleeping:
Sleep loss impairs immune function.
In a huge-scale study, all participants were exposed to a cold virus (rhinovirus) and the participants with poor sleep had developed a common cold, and participants with good sleep showed resistance to the cold virus. It means good and quality sleep is associated with higher resistance to illness and poor sleep efficacy and shorter sleep duration are associated with lower resistance to illness.
A study was conducted between college students with insomnia and without insomnia. The results showed that students with insomnia had lowered immunity to the influenza virus.
The deficiency of omega-3 fatty acids is associated with sleep problems.
A low level of DHA (omega-3 fatty acids) is connected with a low level of the hormone melatonin, which helps you sleep.
Studies disclosed that supplementing with omega-3 increases the period and quality of sleep in both children and adults.
These two benefits of omega 3 fatty acids at the same time, helps in immunity and quality sleep, and these both benefits ultimately boost immunity or the immune system.
7. The right amount of exercise:
Regular exercise improves immune abilities over a lifetime.
Studies showed that regular physical activity (structured and balanced/moderate exercise) decreases the occurrence of many communicable diseases (viral and bacterial infections) and non-communicable diseases (cancer and chronic inflammatory problems).
High-intensity exercises may temporarily decrease immune function.
Intermittent fasting or Ramadan fasting has beneficial effects on immunity and the immune system. Ramadan fasting is a type of intermittent fasting called Daily time-restricted feeding (the Leangains diet-16 fasting hours cycled by 8 non-fasting hours). Muslims fast every day for a month of Ramadan.
9. Minimize stress or live stress-less:
Chronic stress decreases immune function. So try to live stress less life. Try meditation, mindfulness exercises, journaling, yoga, and going for walks, these activities are really helpful to release stress.
10. Limit highly refined carbs:
Refined, added sugars and high carbs diet contribute to obesity and overweight that cause type 2 diabetes and heart disease and these conditions weaken the immune system.
It pops up that people with type 2 diabetes and other metabolic problems are at higher risk of issues from COVID-19.
A study was conducted with 1,000 people with obesity. All people were administered the flu vaccine. People with obesity still get the flu twice as individuals without obesity.
We should strive to limit our sugar intake to
less than 5% daily calories = 2 tablespoons (25 grams) of sugar for someone on a 2,000-calorie diet.
11. Limit intake of alcohol:
Studies show that chronic heavy alcohol consumption and increases susceptibility to infections such as pneumonia, or pneumonia related to COVID-19.
Studies show a high risk among heavy drinkers with acute respiratory stress syndrome (ARDS), a lung disorder that causes the majority of COVID-19-related deaths.
12. Do not smoke:
People who smoke get lung problems such as COPD, and cancer and they are at high risk of getting a respiratory infection. Smoking also harms the immune system.
None of the above things protect or stop getting infections or COVID-19. We can boost up our immunity or immune function by having a good diet, vitamins, quality sleep, staying hydrated, doing the right exercise, limiting alcohol, limiting highly added sugars or high carbs, and avoiding smoking, to fight against infections.
When we get the infection, the immune system starts fighting against infection. Our immune system gets weaken by using all of its resources and our body gets depleted or loses all of the main nutrients and vitamins building immune proteins such as antibodies that are important to keep the fight against infection.
To keep fighting, further processes, and proper functioning of the immune system we need to follow all the advice we mentioned above.