vitamin c

Given everything that’s happened over the last year and a bit, our immune system has become, for a lot of us, a subject of focus.

With that, there has been an unfortunate (but not unexpected) rise in misinformation regarding immunity and how we can “boost it”.

We’re going to cover what exactly the immune system is and how it works, as well what you can do to ensure it’s working exactly how it should be and keeping you healthy!

What exactly is the immune system?

The immune system is a collection of organs, tissues and cells with a whole host of biological functions that work in unison to defend us from outside invaders (pathogens).

It is not a singular “thing” but rather an ever-present network fighting off harmful bacteria, viruses and other microorganisms that may cause disease.

The immune system itself can be roughly split into two camps; our innate immune system and our acquired immune system.

The innate immune system would not be too dissimilar to a “throw everything at the wall and see what sticks” approach. Lacking any form of finesse, the innate immune system will try; flushing out the invading pathogen (with sweat and phlegm for example), burning it out (high and or feverish temperatures) and or going into full “shut down” mode (the extreme fatigue which can accompany illness meaning our body is prioritising the immunity related task at hand).

Whilst it would never be described as accurate, the innate immune system is highly effective and regularly handles issues related to harmful pathogens.

Our acquired immune system operates with much more finesse. When we encounter a pathogen for the first time we develop and store immunological “memory”. This memory essentially serves as a plan of attack for the next time we encounter that pathogen; we use the same process previously employed to defeat the invader allowing for a more effective, enhanced and immediate defensive response.

Can you boost your immune system?

Well, yes, but not in the way that is often promoted (which is quite misleading). Our immunity cannot be “boosted” by a dietary approach and or supplement. The only evidence-based means of boosting our immune system is via vaccination.

Vaccinations present a weakened version of a pathogen allowing our body to develop and record an immunological response in a relatively safe way.

If we were able to “boost” our immune system intermittently then that would actually cause more harm than good. Consider our innate immunity; if that was always “boosted” then we’d feel perpetually sick! Any product or diet that states it has “immunity boosting” properties should be avoided as it’s either a scam and or the manufacturers have no idea how immunity works.

How to live a healthy lifestyle that promotes optimal immunity

So, how can we ensure our immune system is functioning as it should? Well, we really have to focus on three pillars of health; diet, lifestyle and supplementation. Whilst diet and lifestyle obviously have a much more significant role to play, recent research also shows just how important supplementation can be when it comes to optimal immune function.

Diet & Supplementation

The primary consideration of your diet should be that it is well balanced and meets your requirements. Malnutrition and or excessive intakes of certain nutrients or minerals can have an equally detrimental effect on our immune system and should be avoided as best we can.

Next up, we have the gut. The gut is probably the last place you’d have thought about when it comes to immunity but it actually plays a bunch of incredibly important roles.

In fact, the gut is the main “battleground” of the immune system. It is the area in the body where most harmful invaders enter the human system as well as being the home to the majority of the immune cells within the body. This daily war within our gut means that we should be doing all we can to support our immunity troops.

A diet rich in probiotics and prebiotics is a great first step to supporting our gut’s immune troops. Probiotics are live microorganisms which may alter the profile of our gut microbiome to one more conducive to overall health. On the other hand, we have prebiotics which are, more or less, our microbiome’s fuel source. Prebiotics are difficult to digest carbohydrates and fibre which you can find in many plant-based foods (as well as in our snacks!).

Coincidentally, plant-based foods and products also tend to be rich in other nutrients and minerals that can ensure our immunity is in tip top shape!

One such nutrient is vitamin C. Vitamin C is abundant in plants like kiwi fruit, oranges and other brightly coloured fruits and vegetables. It’s an extremely potent anti-inflammatory which can combat inflammation (be it systemic or acute) and support immunity.

Keeping inflammation under control is incredibly important as it relates to supporting our gut. Chronic and or acute inflammation can make it easier for pathogens to get past our defences in the gut. Inflammation can reduce the integrity of the cells lining our gut which can lead to what is often referred to as “leaky gut”.

Omega 3s are a great partner for vitamin C in the fight against inflammation. Not only that but they also play a range of other important roles in regulating our immune systems, including communication, signalling and activation! Achieving at least 2 portions of oily fish, such as salmon or mackerel (in general aim for those darker and or more orange-y coloured fish), should help you meet your required intake of omega 3s (supplementation may also be worth considering for vegans and or non-fish lovers!).

Here’s the point in this article where we sell you our miracle diet! Well, sadly, there’s already a diet that incorporates all these things and more (we’ll get you next time though!). Not the “miracle” diet but the Mediterranean diet; arguably the gold standard of health promoting diets.

The Mediterranean diet is heavily plant based and incorporates far more oily fish than the standard Western diet. The diet is packed full of foods rich in complex carbohydrates, fibre, micronutrients, and other bioactive molecules such as polyphenols and omega 3s. Researchers believe it to be one of the most effective approaches for a well-oiled immune system.

When it comes to diet and supplementation, there are other important considerations to be made.

Vitamin D for starters. In fact, I’d argue that vitamin D is the only “essential” supplement (and its benefits stretch far beyond just our immune system function). Vitamin D actually alters how our immunity functions, making it more effective. Whilst we can achieve vitamin D intake from our diet, this is highly inefficient and not overly realistic in the grand scheme of health and sustainability. Exposure to ultraviolet light (from the sun) converts inactive vitamin D to active vitamin D in our skin, however more than half of all people are still deficient (as this process becomes less efficient with age and many of us don’t get adequate sunlight exposure). Without hesitation I’d happily recommend vitamin D supplementation; one of the few that virtually everyone would benefit from.

It should be noted as well that recent research indicates a possible role for vitamin D in combating COVID-19. Researchers from Ireland have presented vitamin Ds essential role in preventing respiratory infections, reducing antibiotic use, and supporting the immune system's response to infections.

You also can’t forget about zinc and selenium. Two really important dietary minerals that you can find in abundance within nuts, lentils, beans and other pulses, seafood (especially crustaceans), white meat and grains. Both of these minerals play critical roles in how our immune system functions, but also in how quickly and effectively we can recover from infection.

The importance of lifestyle

Our lifestyles can also have a significant impact on our immune system.

Achieving adequate quality sleep helps our immune system in more ways than you may realize. Not only can it impact how our immune system functions, but also our ability to produce immune cells and regulate inflammation. Another super nerdy yet cool function of sleep is how it helps us improve the formation of our immunological memory. Aim for between 7 – 9 hours of sleep a night as consistently as you can and try and destress before bed to ensure quality and quantity sleep!

Speaking of stress, did you know that it can impact how well we can fight off harmful foreign invaders? Whilst a certain amount of stress can be helpful, exceeding what we can cope with can be extremely detrimental. It can hamper our immune system and wreak havoc with our inflammation regulation. Find time for yourself everyday to “loosen the valve” and shed some stress. Try incorporating a least mode activity; an hour a day which helps you “turn your brain off” and relax – perfect before bed!

Exercise is the final lifestyle factor to mention. Not only does it help keep us in a generally healthy state, but it offers unique benefits related directly to immunity. It helps to improve our defensive systems activity whilst also helping the regulation of inflammation. Habitual exercise has so many benefits; if you can find thirty minutes a day to engage in something moderately active then you’ll reap so many benefits (far beyond immunity!).


Immunity is a highly complex system spanning many functions via a multitude of organs, tissues and cells. We can support our immune system with a well-rounded and nourishing diet, correct supplementation and a healthy overall lifestyle. Avoid any products that claim to “boost” your immune system and focus on the basics; a healthy, happy life will keep you well away from the doctors surgery!

Jamie wrightNutrition