Boost your immune system – The body's very own defence against disease

The immune system protects us from viruses, bacteria and other external factors. Whether in everyday life or in times of crisis, it is incredibly important to take action to boost your immune system, or at the very least to avoid actively weakening it.

In this article, we will inform you on how to achieve an immune system boost naturally through diet, exercise and the power of your mind.

Health is an extremely complex issue that affects us all.

In the past, the biomedical community defined health by the two contrary states “healthy” and “sick” – in other words, an either-or model. Over time, we have developed a more sophisticated perspective. Health and illness represent the two endpoints of a spectrum on which we move back and forth throughout our lives, depending on how well or unwell we are at each moment.

How well our immune system works partially determines our position on this scale, as it prevents common and even more serious illnesses when it’s in good shape.

We basically have a defence system that protects us from diseases. There are various factors which can strengthen or weaken our immune system. 

1. Biological system: organism, organs, cells 
2. Psychological system: the mind 
3. Social system: society, family

A biopsychosocial health model not only considers biological factors influencing our health (such as viral infections or vitamin deficiencies), but also psychological influences, such as thought and behaviour patterns or stress. Social factors such as family environment or economic status are also taken into account. Each of these three areas affects our immune system either directly or indirectly.

Several parts of our body combine to form the defence network that we know as the immune system:

• Organs
• Parts of organs
• Cells
• Messenger substances
• Our skin
• Tiny hairs in the nose and lungs
• Mucous membranes
• Blood cells
• Stomach acid
• Lymphatic system
• The gut and its microbiota
• The spleen
• The thymus
• The tonsils

We have a multifaceted protective shield that we take for granted in our everyday life. It’s never allowed any rest due to the fact that pathogens are constantly trying to find a way into our body and make themselves at home.

Viruses, bacteria, fungi, parasites and germs are not only active in winter or in certain places (like a toilet) – they affect us every day. However, a well-functioning immune system renders these microorganisms harmless before they have the chance to make us ill.

You can actively boost or weaken your immune system through your day-to-day behaviour, for example your eating habits, sleep and exercise. Everything that affects the cells in your body influences the function of the immune system:

• Which nutrients are available to your cells?
• How efficiently are these supplied to cells by the circulatory system?
• How well can your cells regenerate?
• Which pollutants (such as nicotine or alcohol) are they exposed to?

The immune system doesn’t follow a binary rule whereby it either works faultlessly or not at all. Rather, the question to ask is how well it works.

Some of the terms in the table don’t speak for themselves, so we’ll explain them briefly. Nonspecific, in the context of an immune reaction, means that the body’s defence cells are not specialised to deal with a specific pathogen. Most of the viruses that cause the annual flu or cold epidemics are mutant viruses. They change from one epidemic to the next, so that they become unrecognisable to our bodies. Since our innate immune system cannot respond to the changed viruses effectively, we have to fight for immunity. 

Our body has certain defence cells for this:

• Immunoglobulins (antibodies)
• White blood cells
• T and B lymphocytes
• Granulocytes
• Monocytes
• Macrophages

While, in a nonspecific response from our innate immune system, all defence cells must first be mobilised to trap and eliminate the threat, our adaptive immune system reacts more efficiently. As soon as the threat is identified and proves to be a known substance, special antibodies are formed that “deactivate” the pathogen.

The B lymphocytes track pathogens, deploy this immune response and coordinate the cooperation of all the components of the immune system. They also have the “memory” element that facilitates the development of immunity to (non-mutant) diseases once they have been overcome by the body once.

When an effective combination of different responses is found to eliminate the pathogen, that combination is stored and recalled the next time the same pathogen is encountered, so that it can be eliminated quickly. In addition, the pathogen is recognised and “marked” faster. This stops the pathogen from multiplying critically again and thus prevents the development of the disease.

As mentioned before, everything we do has an impact on our immune system, as almost every part of the body is involved in the immune system in some way.

When talking about positive and negative influences on the immune system, you should not consider them to be of equal value. You can’t take something away and add something else to compensate for the damage. In general, it is easier and more fruitful to avoid negative influences on the immune system altogether than to attempt to strengthen the immune system in the short term.

Positive influences on the immune system are to be understood as long-term processes, i.e. recurring behaviours. You can weaken your immune system for a short time, for example by sitting in the cold after exercising and drinking a beer. In this state — exhausted, exposed to the cold, and expending energy detoxifying from alcohol — your body is more prone to falling victim to a pathogen. Swallowing down a vitamin C tablet to get your immunity back on track won’t do much, because a vitamin C deficiency is very unlikely to be the issue impairing your entire immune system.

Now for the big question – what actually strengthens your immune system? Many widespread tips, such as washing your hands properly, should not be neglected. But most importantly, a balanced diet provides the ingredients for a natural immune system boost and thus protection from infection.

It is particularly important to ensure you are eating a balanced diet to achieve the maximum performance of the immune system. Fruit and vegetables have an especially high micronutrient density and are therefore essential for strengthening the immune system. Campaigns you might have seen promoting consumption of fruits and vegetables, such as the “5-a-day” rule, have existed for years and are there for a reason. According to the British Dietetic Association, a mere 27 % of adults in the UK and only 8 % of children get their 5-a-day.

The following nutrients have a particularly strong influence on your immune system:

Vitamin A is only created through a series of chemical reactions and is made up of several substances. One of these provitamins that the body converts to vitamin A is beta-carotene. Beta carotene is also a natural colouring agent and is found in all red and orange foods, such as carrot, sweet potato, red pepper, pumpkin and tomato.

You can find more information about vitamin A here.

Contrary to popular belief, citrus fruits are not the vitamin C bombs they are often made out to be. With 176 mg, 100 g of blackcurrants have four times more vitamin C than a lemon. Mangoes, tomatoes, strawberries, and above all rose hips and the acerola cherry are at the top of the ranks for vitamin C content.

Learn more about vitamin C and its benefits here.

Other foods high in vitamin C:

It intercepts free radicals and thus supports the immune system. Free radicals are harmful compounds that are either produced in the body through inflammation or enter from the outside. A portion of hazelnuts (50 g), almonds or sunflower seeds covers the recommended daily intake of 12 mg.

Good sources of vitamin E are spinach, peanuts, asparagus, kiwis, broccoli, squash, beetroot, butter, avocado, almonds and hazelnuts.

Want to learn more? Then take a look at our article about vitamin E.

Zinc is particularly well absorbed from animal foods. Oysters, beef and crabs provide a particularly large amount of zinc, but there is also plenty of zinc in vegetarian and vegan alternatives such as tofu, peanuts and lentils.

You can find out more about the benefits of zinc and other minerals here.

The top 10 foods with the highest zinc content:

Protein does not necessarily have to be obtained from fish, meat and eggs. Beans, nuts, pumpkin seeds and soy products also contain plenty of protein. The defence cells of the immune system mentioned above (with cryptic names such as macrophages) are made up of proteins, meaning a high protein diet supports the formation of these cells.

Of course, other vitamins and minerals such as iron and copper should not be neglected, which is why a varied and nutritious diet consisting mainly of fresh, natural produce forms the basis of a functioning immune system. A diet that includes all vitamins in sufficient quantities is unmistakably colourful. 

If you also want to do something good for your immune system, you should also make sure that you drink plenty of water or unsweetened tea. Keeping the mucous membranes moist helps to keep them resilient and thus wards off pathogens. Sufficient sleep and exercise also help to keep the body healthy and fit in the long term.

The answer to this question is “it depends”. If you eat a very varied diet and are the poster-child of the 5-a-day campaign, your health should be well up to standard. However, there are some external factors that affect your vitamin and mineral balance. Environmental toxins, radiation, lack of sunlight and stress are just a few things that can deprive your body of nutrients.

All in all, not everyone has to take dietary supplements every day. To check whether you are getting enough of all the necessary nutrients, you can have a blood test done by a doctor. A vitamin or mineral deficiency will reveal itself in the results and you can then try to counteract it in a targeted manner.

One vitamin that lots of UK residents are lacking in is vitamin D3. Our body can produce vitamin D by itself when sunlight is absorbed through the skin, but we often don’t get enough sun, especially in winter when its rays are weaker. If you eat a plant-based diet, it generally makes sense to supplement vitamin D, vitamin B12 and, if necessary, zinc and iron. Vitamin B12 is only found naturally in animal products, while zinc and iron from animal sources are absorbed in much higher proportions than from plant sources. 

Many products from pharmacies or supermarkets often do not fulfil their function properly because they are sold in insufficient dosages, in a form that cannot be well absorbed by the body or contains unhealthy fillers and additives. That’s why people often say that dietary supplements don’t achieve anything except “expensive wee”! 

If you want to tackle an existing nutrient deficiency or prevent a potential deficiency, you should invest your money wisely – in high-quality, thoroughly tested supplements with a good composition and a sensible dosage.

The Upfit editorial team recommends the following supplements:

• A high quality multivitamin (this should contain as many as possible of the the others on this list)
• Vitamin D3
• Vitamin B12
• Zink
• Iron
• Magnesium

The effect of exercise on health has long been underestimated. This is probably due to the fact that not so long ago, everyday life involved a lot of exercise. Nowadays, in the digital age, a high percentage of the population has a largely sedentary daily routine and exercise is no longer a given – it must be actively incorporated. 

Only in the last two decades has it become clear that obesity, heart disease, diabetes and stroke are not only related to diet but also to a chronic lack of exercise. Prevention programs by health insurance companies, large-scale campaigns and small aids such as pedometers, sports apps or fitness watches aim to tackle this. The World Health Organization (WHO) recommends 2.5 hours of exercise per week, but, according to Gov.uk, 39 % of UK adults do not get this much.

Can exercise help make us healthier? How exactly does exercise affect our body and our immune system?

On the one hand, exercise is good for your mind. A study of over 10,000 participants from 2013 found that strength training twice a week for 30 minutes has a positive effect on life satisfaction, contentment with one’s own body and fitness as well as leisure activities. In addition, the participants’ strength increased considerably and the average body mass index (BMI) of the group reduced significantly.

Wait a minute – BMI? Indeed, BMI is not the most accurate assessment of health, as it does not take into account body fat percentage, but in larger groups it allows for a simple classification into underweight, of a normal weight, overweight and obese. Excess weight and obesity have a direct negative effect on all aspects of the immune system and are the biggest risk factors for diseases alongside smoking. Therefore, if you exercise regularly, reducing excess weight as you go, you are definitely on the right track to strengthening your immune system.

Click here to calculate your BMI for free.

Smoking comes in second at 52 %, followed by too low a proportion of fruit and vegetables in the diet (31 %), and then alcohol consumption at 26 %.

Lack of exercise is the main cause of obesity not just in adults, but in children too: at 47 %, “insufficient exercise” is the most common trigger for obesity.

But weight loss and positive mental changes aren’t the only benefits of regular exercise. Exercise causes your heart rate, blood pressure and body temperature to rise. This promotes good blood circulation. When circulation is activated, the blood vessels dilate and endorphins (feel-good hormones) are released. In short: exercise ensures that cells remain active and healthy. The body also adapts to regular exercise in the following ways:

• Muscle is built
• Small veins (capillaries) are created for better blood circulation
• Connective tissue and bones are strengthened
• Inflammatory processes are reduced

On the other hand, the cells in an inactive body degenerate and this has a negative effect on the immune system. For example, those who exercise regularly minimise their risk of developing type 2 diabetes. Diabetes has severe negative effects on the immune system.

While diet and exercise play the main roles in determining the condition of the immune system, the mind plays a more minor role and has an indirect effect on our health. The influence of various attitudes and behaviours on the development of cancer and incidence of heart attacks has already led to wider consideration of psychological risks in the medical field.

But what about the general influence of the mind on our health and our immune system? Psychoneuroimmunology deals with direct interactions between the mind, nervous system and immune system. It is already known that the immune system can be accelerated or slowed down by messenger substances in the nervous system. 

The crux of the mind’s influence on the immune system is stress. Chronic stress has a direct negative effect on the immune system and causes the so-called “open window” phenomenon. This works in a similar way to consuming alcohol or cooling down after intense exercise. The open window phenomenon describes your body’s increased susceptibility to infections as a result of high psychological or physical strain. 

Behaviours and emotions that trigger this phenomenon include:

• Suppressing anger
• Depression and low mood
• Anxiety and fear

Only long-term stress has a negative effect on the immune system. Short-term stress, on the other hand, increases the activity of our innate immune system and is associated with the “fight or flight” response. Centuries ago, high immune activity allowed injuries to heal faster and prevented infections.

Find out more about stress here, including how stress arises, what types of stress there are and what influence stress has on your body.

There are two sides of the coin when it comes to the mind and its influence on the immune system. Just as constant stress, anxiety, or the bottling up of negative emotions take a toll on the immune system, other traits can effectively boost it.

The most influential positive mental characteristics are:

• Optimism – a generally positive attitude towards life
• Self-esteem – an overall positive assessment of oneself
• Self-efficacy – belief in yourself, the belief that you are able to get things done successfully and independently
• Social bonds – a feeling of support from one’s social environment
• Positive affects – feelings like gratitude, happiness, excitement, pride, etc.
• Emotional diversity – the ability to distinguish between emotions and thus regulate them better.

Voltaire famously said “I have chosen to be happy – it’s good for my health.”.

He wasn’t wrong: we can indeed work on our attitude and our outlook on life to strengthen our body and its defences. A positive attitude towards life boosts our immune system and our overall well-being. Taking a closer look at this aspect can only be a win-win situation.

Do you sometimes lack motivation or find it difficult to keep positive? Click here to learn some useful tips to boost motivation.

The immune system can be essentially paralysed in the short term by certain behavioural factors. Your immune system could generally be in very good shape – but that won’t be much help if it’s impeded by detrimental habits or substances.

In some cases, a restriction of the immune system’s performance cannot be prevented, for example as a side effect of medication that you have to take. But there are plenty of factors that you have complete control over. Below we have listed the most influential and most common habits that negatively affect your immune system.

This may sound like just another unjustified demonisation, but it’s true: American studies show that alcohol consumption impedes important components of the immune system for 24 hours. On the one hand, the protein receptor TLR4, which mobilises the body’s own defences, is affected. 

The production of cytokines is also reduced. Cytokines are messenger substances that emit attack signals in the event of an infection. Since the immune system remains blocked hours after drinking alcohol, the body is particularly susceptible to infections during this time.

Find out more here about the effects of alcohol on the body and how it can interfere with weight loss.

The same applies to smokers, whose immune system can be permanently damaged by cigarette consumption. Chiefly, the damage to the mucous membranes caused by chemical substances in cigarette smoke makes it easier for viruses and bacteria to enter the body. The cilia, which are important for the removal of pollutants from the bronchi, are paralyzed by the smoke and nicotine over long-term consumption.

According to a study by the University of Washington Medical Center, so-called crash diets also weaken the immune system. It was shown that women who have lost five kilos or more in a very short time at least once in their lives have lower natural killer cell activity. These natural killer cells are the first line of defence in the fight against infection or cancer because they produce important messenger substances and kill infected cells. A change in diet should therefore always be carried out over a longer period of time and be designed to last.

If you make an effort to avoid harmful behaviours, then you’re on your way to boosting your immune system and staying healthy. And in winter, too, when business is booming for the cold and flu viruses!

Even though many of us still believe it, the cold alone does not cause you to catch a cold. Otherwise people in Greenland would have colds all the time. 

Waves of the cold virus cannot just be explained by a weak immune system, either. 

When it’s cold, we prefer to find a nice, well-insulated room where we can warm ourselves up. However, the risk of infection is actually often much higher here: the warm air in particular, heated by radiators, dries out our mucous membranes, making them more susceptible to attacks from viruses and bacteria. 

In addition, due to the lack of direct sunlight and fresh air, less vitamin D is produced in the body, which leads to a weakened immune system. One consequence of this deficiency is that the body cannot adequately defend itself against pathogens. Thus, we recommend that you do the following during wintertime:

• Air out your living space several times a day

• Stimulate blood circulation with walks or easy running sessions

This not only helps to moisturise the mucous membranes, but also supports the transport of immune cells that fight pathogens.

Your immune system is a fascinating network in your body that can keep you healthy on its own every day and protect you from nasty pathogens. Part of your immune system is inherited and protects you from all unknown dangers. You acquire the rest of your immune system over the course of your life. This part has a memory that is activated whenever your body detects a pathogen it has previously encountered. 

To ensure that you support your immune system in the best possible way, you may want to take dietary supplements. Vitamin D3 supplementation is recommended for everyone, while vegans and plant-based dieters should also supplement with vitamin B12 and, if necessary, zinc and iron.

Ultimately, the immune system is a cooperation of many parts of our body, including organs, cells, mucous membranes, the intestine and the lymphatic system. It serves to protect our body from pathogens and maintain our health. A distinction is made between the innate and the adaptive immune system. Adaptive immunity specialises in previously encountered pathogens and is therefore primarily active in events of re-infection.

Three major aspects are important here. First, nutrition: to give your body the micronutrients it needs, such as vitamins A, C and E and zinc, you should incorporate lots of fruit and vegetables into your diet. Furthermore, exercise boosts your immune system: frequent exercise reduces the risk of chronic diseases, stimulates the circulatory system and benefits mental health – which brings us to the third aspect: a positive, optimistic attitude, along with high self-esteem, healthy relationships and a lack of long-term stress, also strengthens the immune system.

Alcohol, environmental toxins, smoking, radiation and crash diets all pose challenges for your immune system. Too little sunlight is just as harmful, as this can lead to a vitamin D deficiency, while chronic stress deprives the body of nutrients and thus weakens the immune system.

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