Like a knight in shining armour, our immune system protects us from foreign invaders that could make us sick. Some of the “soldiers” in this system are trained to turn up at the first sign of attack, while others ingest or absorb the intruders, eliminating them using specialised defence mechanisms. 

Our internal protectors are smart and learn from previous encounters. In fact, they identify and remember what kind of invader tried to penetrate our body and keep a record of how they defeated them to enable a faster and more targeted defence at the first sign of a future incursion. 

The complex army that lives within us survives for merely weeks at a time but is constantly replenished to keep our body safe. These defenders are made in our bone marrow but largely reside within our gut, where we are most prone to attack. 

When working at its best, our immune system helps us to fight off winter's ills and chills and to remain infection-free, but when it is tired and under-resourced, the invaders can run amok, leading to the development of allergies, prolonged infections and autoimmune disorders.

Here are 10 top things you need to know about immunity and how to boost your internal line of defence. 

Stress hurts our immune system 

Our immune system is always ready for anything that comes its way, but it has a limited tolerance for stress. During times of stress and infection, our body releases cortisol and adrenaline (our key stress hormones) to decrease inflammation levels. However, such hormones can inhibit our system from performing at its best and getting rid of invaders. This leads to chronic, low-grade inflammation, which slowly wears down our immunity and leaves us wide open to attack. 

Laugh daily for a better frontline defence 

The saying, “laughter is the best medicine”, may be a cliché, but in the case of our immune system, it has an element of truth. Science shows that laughter boosts the release of dopamine and other feel-good chemicals that help to reduce stress and shore up our defences against infection. Just 20 minutes of laughter a day can help to keep our system in a high state of readiness. 

We need good bugs to maintain our health 

Although we generally regard bugs as dirty, the truth is that we need microbes in and around us in order to stay healthy. Our gut is filled with trillions of them living in synergy with us. These amazing organisms help us to digest our food and produce by-products that nourish us, support our immune system and help to reduce inflammation. Without microbes, we would cease to live – that is how fundamental they are to our existence. We can get our daily dose of good bugs from fermented foods such as sauerkraut, kimchi, miso, coconut yoghurt and kefir. 

Keep your immune system well resourced for a faster recovery 

Our immune system works hard to protect us every day but it needs resources to do so. The key ones are the proteins, vitamins, minerals and antioxidants we get from meat, fruits and vegetables. Eating a palm-sized serving of protein and 800g of fruit and vegetables each day is one of the best ways to keep our immune system functioning well. Whole foods are rich in amino acids (protein building blocks), vitamins, minerals and antioxidants that provide our system with the resources it needs to fight off infections and hasten the road to healing. 

Exercise in a balanced way to stay fighting fit 

Exercise can stimulate our immune system and increase the circulation of immune cells in the body. Daily movement helps us to better prepare for infections and aids early detection of invaders. When our immune system is slow to respond to an incursion, we can find ourselves battling winter ills and chills that can linger and leave us feeling inflamed for longer. 

Sleep is crucial for immunity 

Have you ever been busy and/or missed countless hours of sleep only to come to a standstill and suddenly fall ill with a cold or flu? That’s your immune system getting its game face on. If you’re getting less than 7-9 hours of sleep a night, it can become depressed and leave your body wide open to colds, flu, and infections. Chronic stress and missed sleep hinder your body from warding off infection and leave you exposed to a recurring pattern of illness.

Getting sick is not all bad 

Our immune system is designed to continually learn and adapt and is a key reason human beings have evolved across time. When our body comes into contact with an unknown organism, our system attacks it and also remembers it so it knows what to do if the same foreign entity tries to invade again. Without training and the ability to remember previous invasions, our system has to learn what to do every time it sees a new microbe; this learning process takes time and resources and can make us feel more poorly as our body figures out what to do. However, after the initial incursion is fought off, our immune system has a pre-made plan to deal with subsequent invasions with haste and precision. 

A sober immune system is a good one 

Many of us look forward to the end of the day when we can pour ourselves drink and take a deep breath as we feel our body come down a few notches. Alcohol may make us feel relaxed, but it is a depressant – it can depress our mood and also our immune system. It can directly suppress a number of immune responses and increase our risk of infection. Limiting alcohol to weekends or celebratory events can minimise these effects, especially during winter when many of us hear mulled wine calling our name. 

Support your immune system

Building a diet on nutrient-dense food creates a wonderful foundation for a robust immune system. There are a number of nutrients our body needs to support a robust system while keeping up with the demands of modern life. Sadly, due to these demands and some current farming techniques, food alone may not always provide us with enough of the nutrients we need to ward off winter ailments. Elements such as vitamin C, zinc, and vitamin D are needed in abundance during the colder months to help keep our immune system in top shape. Topping up with immune-boosting nutrients and herbs such as echinacea and holy basil in supplement form can help us sail through winter with ease. 

Sunshine for better defence  

Vitamin D, also known as the “sunshine vitamin”, is crucial to the activation of certain parts of our immune system, and low levels of it can result in compromised immunity and defective immune responses. Vitamin D can be found in oily fish and eggs but most of it is produced in our skin in response to sunlight exposure. To ward off the winter lurgies, put on your gumboots and get outside.