The body has its own natural defense system what we call as the body immune system. And as the name suggests, it has very important function to protect the body from infection, bad microorganisms, germs, and other bad things. What actually is it? How to boost and build it naturally? Here is comprehensive guide.
The main function of the body immune system is to protect the body by keeping any infectious things (such as bad bacteria, fungi, and virus) out of the body – and to kill and remove these bad microorganisms if they do invade the body. So without good immune system, your body is fragile and easy to get sick.
The immune system is made up of complex elements that include special cells, tissues, proteins, and lymphoid organs (organs involved with the body immune system that affect the production and release of leukocytes or white blood cells).
And in general, there are two basic types of white blood cells involved in the function of immune system. These are:
- Phagocytes, white blood cells that ingest invading organisms. There are a number of different cells of phagocytes, and neutrophil is the most common type.
- Lymphocytes, white blood cells that are responsible for immune response, especially to recognize and remember previous invaders and destroy them. It has two main types; B lymphocytes (cells that start growing in bone marrow and mature into B cells, they are intelligence system that looking for invaders and delivering defenses to lock onto them) – and T lymphocytes (cells that mature into T cells, they are like soldiers that go straight to destroy targets that have been identified by the intelligence system).
White blood cells are made or stored in several organs. These lymphoid organs include bone marrow, spleen, and thymus. Furthermore, there is also a complex network of lymphoid tissues distributed widely throughout the body, including lymph nodes ‘oval-shaped organs of lymphatic system’ that also house white blood cells – see the following picture (credit to the University of Chicago Medicine).
How does immune system work?
White blood cells (leukocytes) of immune system circulate through lymphoid organs, lymphatic system, and blood vessels. In this way, the body immune system monitors any invaders and removes them!
Foreign substances that invade and harm the body are called ‘antigens’. If these substances are detected, several different cells work together to identify and respond the invaders. B lymphocytes (the intelligence system of immune system) make special proteins called antibodies that lock onto these antigens.
For instance, if you have a personal history of a certain disease (such as chickenpox), you are less likely to have it for the second time. Unfortunately, this doesn’t go for all diseases.
Immunizations work with this way, too. To prevent particular diseases, an immunization is given to help introduce the immune system to particular antigen so thus the risk of future attack from this antigen can be eliminated.
But antibodies cannot destroy antigen. They are only designed as intelligence system to help respond and recognize an antigen. As mentioned before, the soldier of immune system is T cells (killer cells).
After specific antigen is marked by antibody, T cells are released to help destroy that antigen. And if necessary, T cells may send signals to release other cells (such as phagocytes) to help finish their jobs.
Types of immunity
Now you know that the body immune system is so crucial and important to give protection fighting against the disease. And this protection is what we call as ‘immunity’.
In general, there are two types of immunity; natural and adaptive (acquired) immunity.
As the name suggests, natural immunity is a general protection that you get naturally when you were born and therefore it is also often called innate immunity. This kind of immunity is different to what other species have.
For instance, many viruses that cause diseases in animals don’t affect humans. And on other hand, viruses that attack humans (such as HIV /AIDs) don’t affect your dogs or cats. Natural immunity also includes natural barriers of the body such as our skin and mucous membranes (such as protective membranes covering eye surface, nose, mouth, throat, and urinary tract).
How about acquired immunity? It develops throughout lives. You usually will have it after getting exposure to specific invaders which ‘marked & remembered’ by your immune system.
For instance, you are likely to not have chickenpox for the second time. Immunization is also categorized into acquired immunity.
Furthermore, there is also a type called passive immunity, in which the immunity is delivered from another source and temporary (it lasts for a short time). For instance, breast milk also contains antibodies from the mother that can be so useful to give extra protection for baby in the early years of his /her childhood.
The immune system will come into contact with more and more invaders throughout our lives. Therefore, we are likely to become immune to more invaders as we age – and the answer of why kids are relatively easier to get more colds than teens and adults. The strength of immune system can also vary from person to person.
Many studies have observed the role of some factors (including lifestyle factors) in affecting the body immune system. The results are quite promising, but most of these are still considered preliminary. That’s because the way of how immune system works is not fully understood yet.
But experts believe that there are plenty of options to do to help build immune system and make it stronger. The following are some facts and helpful explanations.
Sleep is essential for the strength of immune system
Does your sleep affect your immune system? There is old wives’ tale that you will get sick more easily if you don’t sleep well. And today, some studies have confirmed that this is true.
In fact many mechanisms and functions in the body are closely associated with the way of how you sleep. One of them is the performance of your body immune system.
One study found that people with adequate sleep and taken flu vaccine were likely to have stronger protection and immunity against the illness. Other studies suggest that sleep deprivation may contribute to decrease the number of T cells (the soldier of immune system, as noted before).
Unfortunately, the number of people with poor sleep is still quite high. Even in the U.S, there are about 50-70 million adults who suffer from sleep disorders.
Lack of sleep is also linked to a number of different mental and physical health conditions – including those that arise from an impaired immune system.
However, immune system is so complex and difficult to understand. The link may be not quite as straightforward as what we think. But in general, most experts believe that the quality of your sleep is important for the health of your immune system in long term.
Nicotine is the main substance in tobacco smoke that causes addiction. In fact, it’s not easy for smokers to quit smoking. Nicotine is so harmful for your health, too!
But what we concern is other harmful substances in tobacco smoke. Even some are carcinogens (harmful agents involved in triggering and causing cancer). For instance, most patients with lung cancer are linked to smoking.
Smoking is also the biggest single risk factor of other cancers, at least 14 cancers. Overall, it is bad for your overall health.
And it can affect the body immune system, too – though this is not fully known yet. In general, its effect on the immune system can cause a number of complications. These may include:
- Greater susceptibility (easier) to have infection.
- Smokers are likely to have low levels of vitamin C or other protective antioxidants in the blood.
- And if they get sick, their body is likely to have longer-lasting and more severe illness.
These suggest that tobacco smoke is bad for your immune system. If you are a smoker and have a plan for quitting, put ‘repairing your body’s defense system’ into the list for one of main reasons to reach the goal!
Good foods to strengthen immune system
Cells and other elements of immune system require good, regular nourishment. That’s why what you eat can play a role, too.
Researchers are continuously observing the immune boosting potential of various different nutrients. These may include vitamins (such as vitamin A, B, C, D, and E), protein, selenium, and zinc.
But remember that the immune system is not a single entity. It is a system and so complex. It requires plenty of numerous different nutrients to keep functioning well.
Furthermore, each food has unique property. Therefore you should not rely on a specific food. Full your diet with a variety of the following immune-boosting foods:
When it comes to building stronger immune system, it’s also important to have healthy guts. Oregano oil can help clean your guts naturally. It also can help reduce unfriendly bacteria in the digestive system.
The use of elderberry is one of old folk remedies. This fruit hosts some essential nutrients that may help build immunity and make it stronger – though more studies are needed.
For instance, it is high in antioxidants. Elderberry extract may help fight against flu viruses, according to some lab studies.
It can be another healthy choice in your immunity boosting diet. The black color of this berry means it is high in anthocyanins, essential antioxidant.
These fruits are very high in vitamin C, even 5 times higher than what we find in oranges. And as well we know that vitamin C is thought as one of essential vitamins for powerful immunity booster.
Moreover, blackcurrants also host potent compound called anthocyanosides that may help provide better vision.
For many years, soursop has been used for traditional treatment to help treat colds & flu, kill parasites, and reduce fevers.
It contains annonaceous acetogenins, natural potent compound that may provide anti-tumor properties. In other words, it may have an effect in fighting against cancer cells and thus help strengthen immune system.
It contains live-active cultures called probiotics, healthy bacteria to help keep guts clean from disease-causing germs. For best result, choose low-fat yogurt – especially true if you are also expecting weight loss!
Another great immunity boosting food is Japanese mushrooms. They are high in antioxidants called ergothioneine.
Enoki and shitake are yummy and loaded with many healthy Japanese mushrooms. The good news, ergothioneine in these Japanese foods doesn’t get damaged during the cooking process.
Oats and Barley
Oats and barley have got beta-glucan in them, essential fiber that is not only good for guts but also has antimicrobial & antioxidant capabilities more effective than Echinacea (a popular herb to help treat flu and colds).
In human, beta-glucan may help speed wound healing, make antibiotic work better, and strengthen immunity. And if animals eat it, they are less likely to have herpes, influenza, or anthrax.
These veggies include lettuce, cabbage, and kale. They can help boost the performance of the liver.
If your liver is able to detoxify and work well, this can flush out toxins more optimally and provide a friendly environment for immune cells. As a result, you are also likely to have stronger immunity.
It also belongs to cruciferous veggies. It provides antioxidant glutathione, vitamin A, and vitamin C (essential nutrients to help protect the body from damage).
Another vegetable you need to put on your list is spinach. It is high in folate, essential substance to help repair DNA and make new healthy cells. It is also loaded with high fiber and antioxidants (like vitamin C).
To gain the most nutrient content of spinach, eat spinach raw! Or if you want to cook it, just make sure to NOT too over cook it (lightly cooked is more recommended)!
It is not only good for flavoring, but also has been used for remedy. It has potent substance called allicin that can help fight against bacteria and infection. It also has an effect to reduce the risk of having cold, according to a British study.
It’s not only ‘yummy’ in taste, but also can help provide numerous different health benefits. It is rich in antioxidants, healthy (unsaturated) fats, and amino acids. Some of these essential substances are great to support adrenal function, maintain the balance of hormone production, and improve the immunity.
This fruit is not only good to refresh your thirst and keep you hydrated, but also good source for glutathione, an antioxidant that may also help build and boost immunity. Glutathione in watermelon is high in the red pulpy flesh close to the rind.
Chicken soup is good in taste, and many people love it. But did you know that it can be one of your immunity boosting foods, too?
The answer may come from amino acid cystein released from chicken when you cook it. But if you concern to LDL (bad cholesterol), skip the chicken’s skin. Add your soup with onions and garlic to get more immune-boosting power.
It is good source for B vitamins, antioxidants, and zinc. It also provides a good mix of healthy fat, protein, and fiber. Therefore, it can help maintain your healthy weight, too.
People who drink tea are likely to have more virus-fighting interferon in the blood, according to a Harvard research.
Amino acid called L-theanine in tea may also help strengthen immunity. It can be found in both green and black tea, including for decaf versions. Furthermore, tea has polyphenols and flavonoids, potent antioxidants to help protect the body from free radicals.
Eggs are practical and affordable. They are also rich in nutrients such as protein, vitamin B12, biotin, and iron.
Some experts believe that eating eggs may help improve immunity, too. But remember that egg yolk contain cholesterol. So if you eat more than 1-2 eggs a day, skip the yolk (especially true if you do concern about your blood cholesterol)!
As mentioned before, your skin is part of your natural immunity. But it is also susceptible to the attack of many invaders since it is the largest organ (covering the body from scalp to soles of feet) and the first-line barrier to get contact to viruses, bacteria, or other bad things in environment.
Like other organs, cells of skin also require regular nourishment to keep the skin healthy and strong. And vitamin A is one of essential nutrient required. Sweet potatoes are rich in beta-carotene, which will turn into vitamin A in the body.
They contain zinc, which may help fight against viral infection. Zinc itself may be involved to help create and activate leukocytes in the immune response. It may also assist some tasks of immune system like healing wounds.
In addition, other shellfish such as clams, lobsters, and crabs are also helpful to stimulate the production of cytokines (proteins to help remove flu viruses out of the body).
Does exercise help build immune system stronger?
Exercise is one of the keys in healthy lifestyle and healthy living. It provides lots of health benefits. And ‘yap’, it is also great for your immunity.
Just like in healthy-balanced diet, exercise can carry positive effect in general health, including for immune system. It can promote healthier blood circulation in the body, allowing substances and cells involved in immune system to move and do their job more effectively.
But the exact way of how exercise can affect the performance of immune system also remains puzzling. Exercise does have an effect in immune system, but this is not easy to understand.
For instances, it’s not clear yet whether an increase in cytokines is useful or causes any true effect on human immune response – and whether an increase in leucocytes also does cause positive effect!
But overall experts do believe that there is positive effect of moderate exercise that most people have on immune system, though the reason remains unclear and the link has not been established. Exercise is also good to promote other factors that boost your immunity such as sleep well, healthy weight, and having more body’s feel-good chemicals.
And the most important thing you need to remember, the matter is not how hard you exercise – but how you can make it regularly. You need to do it regularly to gain the most benefit from your exercise!
Don’t push yourself too far! Even a regular, moderate exercise (such as a daily-30 minute walk) is helpful.
Are there any supplements and herbs that work?
In fact there is no clearly guideline in which cells or components of immune system that should be boosted to have the optimum performance of immune system.
What experts know is the problem will come if particular cells of immune system drop lower than normal.
For example, if T cells are lower than normal, the body is fragile and more susceptible to infection. So, there is a bottom number in which immune system doesn’t work properly. But the best number of T cells to make immune system work much better is unknown.
Another issue – experts also don’t know, for instance, whether specific herb or supplement that seems to help increase the levels of antibodies in the bloodstream is actually doing anything beneficial for the overall performance of the body immune system!
So taking herb or vitamin in pill to boost immune system is not always necessary. But if you do believe that certain supplement or herb can help make you better, it’s much better to talk first with your physician (especially if you are also taking certain medication)!
Furthermore, not all herbs have been confirmed by research. There are some that have been scientifically observed – but mostly with preliminary studies, which means the results cannot be considered universally applicable (more studies are required to disapprove or confirm the results).
The following are some herbs and vitamins that have drawn more attention from researchers: