Immunity – what is it, and how to boost it?

Manoj Pandey*

Caution: This is a long article. Read it at leisure, or jump to the questions/ sections linked below!

The Covid epidemic made the expression immunity fashionable enough to be thrown into any discussion on health. It also made the word worthy of exploitation for commercial gains. 

Recall the period when the epidemic was spreading dangerously fast, and no cure for the epidemic was visible. Self-styled health advisors, quacks and even pharma companies exploited people’s anxiety to sell all sorts of medicines, tonics, juices and concoctions in the name of boosting immunity. Of course, there were many, especially genuine experts and government agencies, correctly advising people on improving immunity for warding off the fatal virus.  

The epidemic is over but immunity sellers are still making a heyday. Clever marketing, exaggerated claims and outright misinformation are openly being used for fleecing people, even playing with their health. 

The present discussion seeks to demystify the concept of immunity so that readers are able to take informed decisions regarding what, how much and when to take substances associated with boosting immunity.

What is immunity?

In simple words, immunity refers to the ability to fight disease-causing germs. In the same vein, immune system includes everything in our body that protects it from pathogens. Pathogens include bacteria, viruses, protozoa, fungi and similar other germs that cause infections. Not only do these germs cause physical harm to the body, they release harmful chemicals which compromise our body’s well-being. 

A comparison of human immune system with the security system of a nation makes it easy to appreciate the way immunity works. The responsibility of the security of a nation primarily rests with the armed forces. This comprises the army fighting on the borders, with small weapons, artillery, tanks, ships, fighter planes, missiles, etc. However, for keeping the nation fully secure, it is very important that institutions such as the police and paramilitary forces, civil defence and intelligence work properly even when there is no perceived threat or a war. The economic prosperity plays an important role in own preparedness as well as a deterrent. Equally important is citizens’ patriotism, and their capacity to contribute to the defence of the nation in times of internal crises and wars.

Let’s visualise its parallels in our body. Our skin is the biggest and most effective shield to protect us from diseases. Acid produced in the stomach, saliva produced in the mouth, mucus in the nose, lungs and intestines – there are many such chemical barriers that work on the germs when they come in contact with our inner, soft, linings. These protect the body against germs, and also signal the main immune system – the armed forces – against enemy attacks. When we take care to keep the skin clean, do not take harmful foods and drinks, and take actions required to keep the body healthy, harmful germs find it difficult to cause diseases.

But germs can still enter the body and try to harm it. Here come the armed forces: the main immune system. In the language of research and medical science, when we talk about immune system and immunity, we mostly concentrate on the working of this set of organs and processes.  

You would know about lymph. If not, let us talk briefly about it. Much like blood, another, colourless, fluid keeps flowing in different parts of our body. There are some big lymph vessels, but at minute level they are not as elaborate as the thin blood vessels and capillaries, and lymph occupies the space between cells. At some places, blood and lymph get mixed.

There are many special organs that make part of the lymph system or are deeply integrated with it. These include bone marrow (generally speaking, the flesh inside big bones), thymus gland (a small gland near the heart), spleen and tonsils on the sides of our throat, and a number of lymph nodes. These organs produce special fighter cells called lymphocytes and release them into lymph. When there is an infection, there is a greater need for such cells, and these organs become more active. In blood, another set of fighter cells is similarly present, which together are called white blood cells. A type of such cells, called T cells, have the ability to ‘remember’ earlier attacks. These organs, fighter cells and the chemicals and signals they generate for defence together are like the armed forces; they are the core immune system.

This whole system is very complicated, so let’s leave out its technical details. Nevertheless, two small points are worth mention. When a blood test is taken, there is a reading regarding white blood cells and lymphocytes. A higher-than-normal count of such cells indicates either an infection or malfunctioning of the immune system. During a discussion on diseases, we also frequently come across the words antigens and antibodies. Antigens refer to the germs or their fragments or proteinaceous chemicals released by them. In response to antigens, our defence system releases proteins called antibodies, which bind with antigens to render them harmless.  

How is immunity measured? How much immunity should one have for good health?

There is no single measurement to define a person’s immunity. Being the overall capacity to fight infections, immunity depends on a large number of factors.

A person with high immunity might still be prone to attack by a particular pathogen. His/ her system might also get compromised due to environmental factors. There could be triggers that aggravate the immune system’s response, thus leading to another set of health issues.    

For our immune system to function properly, the cells and chemicals in the system should be in the right quantity and in a proper functioning state. For example, fighter cells and antibodies should be in the right quantity and proportion, neither more nor less. If one type of cell is present in more than normal numbers and the other is less than normal, that too is a problem. If the cells are there in the right number but start fighting with our own organs – that is even more dangerous.

Since merely increasing the number of immunity-producing cells or chemicals would not improve immunity, you would appreciate that much of the talk of greatly boosting one’s immunity with a tonic falls flat. 

Does it mean that the tonics, concoctions, etc being sold for boosting immunity are useless?

It cannot be answered with an absolute yes or no

We’d discuss this matter again later in detail. Right now, let me re-emphasize that like a nation, body’s overall health itself is a great protective force. Besides, there are proven ways to keep the core immune system in good shape. There also are foods and medicines that improve the functioning of different organs, especially those connected with immunity. There are specific treatments now available to deal with malfunctioning of the immune system. 

Problems arise when we start taking foods and medicines based on wrong information and follow the advice touted on the social media or hearsay or exaggerated claims made in advertisements. Even if a substance (e.g. a herb, an Ayurvedic tonic, or a micronutrient supplement) has been proven to boost immunity, its wrong use or overuse can harm us in unintended ways. 

What are the general symptoms of weak immunity?

When we catch a cold during the change of seasons or when we are suddenly exposed to extreme cold air, we might feel that this happens due to low immunity. Similarly, children’s frequent runny nose and sneezing are also taken as a symptom of low immunity. In reality, such ailments do not signify low immunity. 

When infections recur with a high frequency or linger on, they might indicate low immunity. The following are some symptoms of a lower immunity: 

  • Nasal and respiratory tract infections, such as colds and bronchitis, when these occur more than four times in a year, year after year, and take a long time to heal.
  • Getting pneumonia twice within a year.
  • Sinusitis, which does not get better in a few days. 
  • Ear infections, when they occur four or more times in a year.
  • Frequent and long-lasting abdominal health problems, such as constipation, gas complaints, diarrhoea and vomiting.
  • When small scratches and wounds do not heal for a long time.
  • When we need to take antibiotics two or more times within a year.
  • Constantly feeling tired despite getting enough sleep.

Is it true that minor infections increase immunity?

That is right.

Just like soldiers need training and experience before they can take on the enemy, the immune organs and fighter cells in our body, and the body as a whole, need to learn identifying the enemy, attacking it and adapting for future attacks. 

Small infections help the body learn and get on-the-job training in warfare. Two types of fighter cells, known as B and T lymph cells, even have the ability to ‘remember’ previous attacks. For this reason, when children grow up, their defence system or immunity becomes stronger. Vaccines also work on the same principle. We shall talk about these in more detail while answering the following questions.

Do small children and old people have low immunity?

As discussed in the previous question, children’s immunity is low because their bodies, especially their fighter cells, are yet to be confronted with common pathogens and learn to fight them.

On the other hand, immunity decreases in old people because the immune system weakens with age. Besides, at old age, other organs and systems and various biological activities are in no position to support the immune system. It is like the situation in which the armed forces are ill-equipped, there is breakdown in the social structure, the economy is getting worse – and these all are leading to a failing state. 

Let us take stock of what specifically leads to the progressive decline in immunity in elderly people. Research has shown that in old age, the capacity of bone marrows the thymus gland goes down, due to which some types of fighter cells are produced in insufficient quantities. The body does not get necessary micronutrients due to the weakening of the digestive system, further incapacitating the immune system. Weakening of the immune system results in a vicious cycle in which more infections, more misbehaving cells, weak organs and weak metabolism promote one another. It has also been observed that as the immune system weakens with age, effectiveness of vaccines also reduces.

Does immunity decrease in winters?

Occurrence of diseases during change of season should not be linked directly with one’s immunity. Change in season, especially the onset of winters, comes with resurgence in many pathogens, change in atmospheric humidity, cold shock to the ear-nose-throat linings, and so on. Winters also bring about changes in lifestyles, which include changes in eating, sleeping, clothing, room heating, festivities, etc. These can increase the body’s sensitivity and sometimes make it more prone to opportunistic attack by pathogens.

It is also true that many biological functions of our body keep changing with the seasons throughout the year. In some research, seasonal changes in the level of immunity in humans has been documented, but not to a significant level.

Does too much immunity cause diseases?

As explained earlier, immunity is not a simple game of increasing or decreasing a particular number.

While it is without doubt that lower than the desirable number of fighter cells or their impaired working leads to decline in immunity, a higher number or overactivity is not a sign of high immunity. In fact, when the quantity of particular types of fighter cells or chemicals becomes more than the optimum level, that can lead to serious health issues. 

In one type of diseases, called autoimmune diseases, the cells of the immune system start attacking our body, much like rogue and mutinous soldiers. A common example of this is rheumatoid arthritis. This is a type of joint pain in which the immune system destroys the tissues of the joints, due to which the joints become weak and painful, they cannot bend or move correctly, and they are unable to carry weight.

Therefore, when we talk of boosting immunity, our aim should be to optimise the working of the immune system, not increasing figher cells or chemicals to the maximum.

The discussion on keeping the immune system in check will continue in the next couple of questions.

Are allergies and asthma related to immunity?

They both are.

Allergies are manifestations of our body’s reaction to outside objects and chemicals, especially those containing living matter and proteins. When our body reacts aggressively on eating or inhaling a particular substance, taking a medicine or injection, or when our skin comes in contact with something we are said to be allergic to that thing.

Allergy occurs because our defence system gets a sense that the body is under attack, and it starts using more ammunition than necessary to fight the supposed attack. This over-aggressiveness comes out in the form of symptoms such as fever, hives and itching, sneezing and runny nose, vomiting, and diarrhoea.

Something similar happens in asthma. In a certain environment, some cells in the lining of the respiratory tract become more active than necessary and produce chemicals that cause swelling in the lining, make breathing difficult and sometimes result in other, more severe, symptoms.

It was earlier believed that the immune system played a role only in asthma caused by allergies, but in-depth research at molecular levels has revealed that immunity-related cells and chemicals play a role in all types of asthma.

People who suffer from allergies and asthma are generally healthy. Just when there are conditions conducive to allergy or asthma, their immune system gets disturbed. In such cases, the treatment is around subduing symptoms and mollifying the immune system. On the other hand, for people whose asthma is triggered by respiratory infections, it is important to pay attention to raising immunity against those infections. For example, getting a flu vaccine regularly can be an effective intervention for asthma patients whose asthma aggravates with flu.

Are tumours and cancer linked to immunity?

Tumour and cancer arise when some cells, instead of doing their proper work, start constantly producing many similar cells. These baby cells either become worthless like the parental cells or start generating more such cells. In this way, they keep taking food from the body without doing any work. 

In a tumour, this enlarged flesh of worthless cells remains in its place, and it does not generally grow again after the first lump is removed. In cancer, continuously growing cells become a burden on other tissues and do not allow them to function properly. They also spread to other organs, due to which the body eventually gives way to the disease. In general, cancers have the tendency to grow again when the parental cancer cells are removed. 

A small number of cells keep forming tumours – and potential cancers –  throughout life. If the body is healthy and the lifestyle too is healthy, then the immune system works well and keeps the production of such cells in check. Even if bad cells are formed, a strong immune system eliminates them before they can become cancerous.

With increasing age, the number of these worthless and/or harmful cells increases, and the immune system, which itself has become weak, is not able to cope with them. In such a situation the immune system is defeated and cancer takes over. Some types of cancer cells are adept at dodging the immune system, so can result in cancer even if the immune system is otherwise well-tuned.

A few genetic factors and internal biological processes are responsible for tumour and cancer. Some external substances like tobacco, various types of chemicals used in industry, junk food, and ionizing radiation cause tumour and cancer, and promote their growth.

Cancers grow more in some organs than in others. Sometimes they also develop in the organs of the immune system. One such cancer is leukaemia or blood cancer. In this cancer, bone marrows start producing white blood cells in large numbers and, instead of fighting the enemy, they become a burden on the body. Similarly, in a cancer called lymphoma, lymph cells start forming in large numbers. Such cancers are similar to a situation in which a large number of the people in a nation do not allow sincere workers to do their jobs while themselves destroying the infrastructure, thus ruining the social fabric and the economy, allowing enemies to take over.

What is the relationship between vaccine and immunity?

We have been a witness to and participants in ‘universal immunization’ of children for decades now. It is believed that it has been possible to eliminate or substantially bring down many erstwhile fatal diseases of epidemic proportions only because of this intervention. In addition, need-based vaccination is carried out to protect people against particular diseases, such as flu and covid.

A vaccine contains very weak pathogens or their fragments or the bioactive chemicals released by them. When the vaccine is administered to an individual, his/ her immune cells respond to the supposed attack, and in this process learn to identify the pathogen and prepare themselves for subsequent attacks. When that pathogen actually attacks that person, after vaccination, the immune system is already prepared to fight it.

By administering a vaccine, immunity is created against that particular disease, but it does not boost the immunity of that person against all diseases. Moreover, vaccines are effective only in those types of infections whose pathogens can be remembered by the immune system.

Vaccines are not always effective; they are also not always safe. This happens because the person’s immune system is not able to fight even the weak germs of the vaccine or uses more ammunition than necessary to fight the vaccine or prompts the whole body to get unduly aggressive. In some cases, vaccines are also found to cause long-term health issues. Yet, immunization constitutes a very potent arsenal against a large number of infectious diseases, and the mainstream medical science swears by it.

On the other hand, it is also true that the immunity of the body of healthy people itself can prevent most diseases, immunity is generated even from small infections, and at least some people develop health problems after vaccination. Considering these, some experts argue that vaccination should not be made compulsory. I won’t be able to do justice with this debate in this already too long discussion, so please allow me to rest it at that.

If you are interested in continuing the discussion on vaccination, I would advise you to visit this article on Raag Delhi, titled, Are vaccines a solution to epidemics like COVID-19?  

Some people benefit from medicines for increasing immunity while some do not. Why so?

I might have a high level of immunity with a particular combination of cells, metabolic status, biochemicals, etc, while you might have an equally high level of immunity with a widely different combination of these attributes. At the same time, while I might be susceptible to a specific strain of coronavirus, you could be fully immune against that but prone to attack by some other virus.

The reasons for this variation lie at cellular and molecular levels. Let us understand this with a simple example. Suppose a medicine or the juice of a leaf or an Ayurvedic tonic has the potential to increase T cells (a type of fighter cells) in humans. If a person with a low count of these cells takes that medicine, he/ she is likely to benefit but a person with an elevated count of these cells takes the same medicine, he/ she might develop serious health issues.  

Do alcohol and smoking harm immunity?

If alcohol is consumed beyond the safe limits suggested by health authorities, it can hurt immunity in many ways. Firstly, alcohol directly affects the working of the immune system. In addition, by weakening or damaging some important organs such as liver and heart, alcohol reduces the body’s overall capacity to fight infections. Alcohol also hampers recovery after a disease has occurred.  

Similarly, tobacco smoking or chewing hurts immunity in many ways. The smoke reduces the intake of oxygen. It has harmful chemicals that directly impact health. With regular smoking, the functioning of lungs and the windpipe can get impaired permanently. What’s more, the dangerous chemicals in tobacco and its smoke give wrong signals to the immune system, seriously impairing its functioning.

And, as discussed earlier, the use of alcohol and tobacco makes some cells crazy, and if the immune system is unable to subdue them, they can cause tumour and cancer.

Does immunity decline with excessive sex and increase with abstinence?

Such notions are widespread in some religious sects, and are also often propagated during religious discourses. However, scientific evidence supporting such notions is wanting. 

On the contrary, some experts believe that sex is an activity beneficial for health, and the hormones produced in sexual activity can enhance immunity.

Very little research seems to have been done on this issue in modern medicine, and whatever has been done has not yielded substantial results. I have come across two small studies, which have shown that having sex increases immunity, but we cannot draw conclusive inference unless studies are conducted on a large scale.

Does stress reduce immunity? Does meditation boost it?

Stress impacts immunity in at least two ways. Firstly, it impairs or damages many organs and biological processes. Stress results in poor sleep, disturbs digestion, and leads to irregular blood pressure and blood sugar level; such disturbances indirectly lead to poor immunity.

It has also been observed in medical studies that stress produces chemicals that disrupt the functioning of fighter cells.

Meditation works just the opposite, and, thus, helps in keeping the immunity intact in a number of ways. For example, it improves the health of heart, brain and nerves. It also increases production of the right kind of hormones and reduces secretion of aggression-inducing hormones. By calming the body’s metabolic activities, meditation helps in the repair of the body.

Do fresh fruits and vegetables increase immunity? Do organic foods increase immunity even more?

It is absolutely true that fresh fruits and vegetables increase immunity, and there are three big reasons for this. 

Firstly, fresh fruits and vegetables contain essential vitamins and minerals in abundance. Secondly, they also contain some bioactive chemicals which give strength to our organs. Thirdly, they help in the growth of good bacteria in our guts. It has been scientifically proven that these bacteria help in keeping us protected from infections.

Organic food is produced and processed without the application of fertilisers, pesticides, herbicides and other industrial chemicals. It is true that the chemicals used in growing crops lead to health issues, including loss of immunity. Therefore, it can be said that organic fruits and vegetables help in keeping immunity high, without causing harm that can arise from chemicals used in non-organic produce.  

Does taking multivitamins and nutrient supplements increase immunity? Does regular intake of Vitamin C prevent infections?

Research has proved that many vitamins help in fighting diseases, prominent being vitamins A, B6, B9, B12, C, D, E, and K. Minerals and other elemental micronutrients such as copper, iodine, iron, magnesium, selenium, and zinc have a special role in maintaining proper immunity.

While it is well-established that vitamin C helps in improving immunity, not all research supports the miraculous benefits often associated with it.

While micronutrients are essential for health, many of them can lead to toxicity and other harms if taken in excess. Therefore, it can be said that consuming micronutrient-rich tonics, supplements or medicines can help in improving immunity only when taken to compensate for their deficiency arising due to less intake or poor absorption or excess leaching due to some disease.

Does consumption of Ayurvedic tonics, aromatic spices and herbs increase immunity?

Some Ayurvedic tonics are sold in the market with superlative claims about their immunity-boosting properties. Chyawanprash, Swarna Bhasma, Shilajit, some asavas and arishts are among the most acclaimed immunity-boosters. Some spices and herbs are also supposed to have miraculous healing and immunity-boosting properties. Some medicinal plants and their products, such as amla, turmeric, garlic, ashwagandha, giloy, triphala and tulsi also come in this category. 

On social media and instant messaging platforms, people spread eye-popping benefits from some types of concoctions, teas and juices. Some waters, such as copper water, alkaline water, and neem and lime water are also touted to boost immunity.

In the recent past, a great deal of research has been conducted on medicinal herbs, spices and other ingredients used in traditional medicine and Ayurveda, and it has, indeed, been found that the chemicals found in some of them increase immunity either directly or by strengthening our vital organs.

However, there is a need to pay attention to the right quantity and right time to take them. It should also be kept in mind that a very useful medicine, whether Ayurvedic or of any other system of medicine, should be taken with caution in such conditions as pregnancy, metabolic diseases, and in combination with other medicines and food. 

Let me also draw your attention to one more issue with natural medicines. In the case of modern medicine, the ingredients are specific, and their side effects are fully known. On the other hand, in traditional medicines, there are many bioactive chemicals which are either ignored or there is not enough research done so far about their possible side effects. Therefore, if taken without expert guidance, excess or wrong use of traditional medicines can lead to unintended health consequences. 

The takeaways

We have had enough discussion; so, without much ado, let me give you parting takeaways on improving immunity the right way. 

When I was sifting through expert tips about boosting immunity, I found that the world’s most trusted researchers and experts do not, in normal situations, recommend any medicine or tonic for boosting immunity. Only when there is a major disturbance in immunity, they recommend medication, that too specific to the condition and after proper diagnosis. 

Here come the expert tips on boosting immunity:  

  • Maintain proper eating habits. That would include taking a balanced diet, reducing the intake of junk food, and taking medicines and supplements in case of deficiency. Regularly consume food items that have been proven to improve immunity. These include fresh fruits and vegetables, especially green vegetables and salads, nuts and seeds, and probiotic foods. Also include immunity booster herbs and spices in your food. This includes turmeric, ginger, garlic and some other spices. Avoid consuming them in excess and in the wrong way.
  • If you are the mother of a small child, breastfeed her.
  • Sleep enough, and try to get deep sleep.
  • Do regular exercises suiting your age. Include yogasanas and pranayams. Meditate regularly, even if for a short duration.
  • Take care of cleanliness, but do not be obsessed with it.  
  • Keep your weight in check, because excess weight puts stress on the organs, and causes some internal diseases, due to which the body is not able to fight germs properly. Also, excess weight has been shown to be related to some types of diseases related to the immune system.
  • Do not be constantly under tension.
  • Avoid smoking and chewing tobacco and reduce alcohol consumption.
  • Reduce the consumption of beauty products containing harmful/ strong chemicals. If you need to apply such products, remove them after use. If possible, avoid chemical-based products that stay on the body for a long time, such as hair dyes, hair conditioners and scents. 
  • Get children vaccinated as required. Taking medical advice, go for vaccination during epidemics and when visiting a place known to have endemic infectious diseases. 

Further reading

You can watch a related Hindi video, explaining these concepts and providing tips on improving immunity, below. In case the video does not open in your browser, kindly click on this link: इम्युनिटी क्या है, इसे कैसे बढ़ाएं?

*Manoj Pandey is a former civil servant. He does not like to call himself a rationalist, but insists on scrutiny of apparent myths as well as what are supposed to be immutable scientific facts. He maintains a personal blog, Th_ink

Disclaimer: The views expressed in this article are the personal opinion of the author and do not reflect the views of which does not assume any responsibility for the same.


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