Updated: Nov 5
Understanding how our immune system functions and how best to support regular functionality has never been so important. In this article we're going to briefly describe how exactly immunity works, why the goal should be to "support functionality" rather than "boost" it and what we can do from a dietary, lifestyle and supplementation approach to ensure we're staving off any nasty viruses, bugs or whatever else that we may encounter.
Immunity; a brief overview
The first misconception surrounding the immune system is that it is a singular thing. However, this is most definitely not the case. The clue here being that we describe it as the immune "system"; it is not a singular thing but instead a collection of many organs and biological functions acting to defend our body from harmful pathogens (bacterium, viruses, or other microorganisms that can cause disease).
In simplified terms, the immune system can be broadly split into two parts; the innate and the acquired/adaptive immune systems.
The innate system is our body's initial, primary form of defence (well technically our skin is but we're talking beneath the bonnet here). The innate system is akin to letting a bull loose in a china shop. It's not much for finesse but it's regularly very effective, flushing out the invading pathogen (sweat and phlegm for example), burning it out (when you experience feverish temperatures) and shutting down the body so that it can focus on the task at hand (which explains the often extreme fatigue we experience once ill).
The other camp of immunity, the acquired/adaptive immune system, is much more concise. Quite simply, it is the store immunological response to a given pathogen. This allows your body to deliver a much more effective, enhanced and immediate defensive response to rid yourself of the bothersome pathogen.
Supporting over boosting; focusing on the right goals
Whether it be through lack of understanding or simply a marketing tool, there are many "experts" and companies who are claiming that their given product and or diet can boost your immune system.
This is simply not the case. Vaccinations are the only evidence-based intervention which can "boost" our immune system (as vaccines are a weakened version of a pathogen, it allows our body to develop and record an immunological response in a relatively safe manner). More importantly however, boosting your immune system would not be a desirable effect to begin with and would actually make you feel perpetually unwell.
As we now know how the innate immune system functions, imagine it was active continuously? Well, you'd simply feel ill indefinitely without their being any real benefit. You may not even have come into contact with a pathogen in the first place and you're making your body feel terrible for no reason!
This is why the emphasis should be on "supporting" our immune system and its normalized function, not "boosting" it.
Supporting your immune system with diet, lifestyle and supplementation
First and foremost, if we are achieving a well-balanced diet and maintaining a lifestyle of healthy behaviours our immune system will most likely be functioning as it should. Malnutrition and or excessive intakes of a given certain nutrient or mineral can have an equally detrimental effect on our immune system.
The gut plays a crucial, yet underrated role in immunity. In fact, a great deal of the ongoing war of immunity occurs in the gut!
Not only is it the site where most invading pathogens enter the human system but it is also home to the majority of the immune cells within the body. Maintaining a healthy gut microbiota is incredibly important for overall health but also in the ongoing fight to support a healthy immune system.
Chronic and acute bouts of inflammation can also leave us more susceptible to pathogen invasion. Relating back to the gut, inflammation may contribute to the development of a "leaky gut" or, more accurately, reduced integrity of the cells lining the gut (allowing for more free passage of potentially harmful pathogens).
Probiotics and prebiotics appear to be effective supporters of our gut's health state and its role in the immune system.
Probiotics are live microorganisms which may change the profile of our gut microbiome to one more desirable, whereas prebiotics act very much like our microbiome's fuel source.
Increasing your intake of plant-based foods and products, as well as fermented foods, is a sure fire way to up your prebiotic and probiotic intake!
Additionally, it may be worth considering supplementing with a probiotic supplement too especially if you've travelled recently, experienced digestive issues or have taken (and finished) a course of antibiotics.
Coincidentally, plant-based foods and products also tend to be richer in other nutrients and minerals that can ensure our immunity is in tip top shape!
A Mediterranean diet style approach, which is one that incorporates plenty of plants and oily fish rich in complex carbohydrates, fibre, micronutrients, and other bioactive molecules such as polyphenols and omega 3 polyunsaturated fatty acids (PUFAs are a healthy fat that may also be of benefit to heart and cognitive health), can stave off inflammation.
Vitamin C, which is abundant in plants, particularly kiwi fruit, oranges and other brightly coloured fruits and vegetables, is a potent anti-inflammatory which can combat inflammation (be it systemic or acute).
Omega 3 fatty acids serve a similar function. Achieving at least 2 portions of oily fish, such as salmon or mackerel (in general, darker and or more orange-y coloured fish are the richest food sources of omega 3 fatty acids), should help you meet your intake.
Supplementation is a useful safety net if you're not a fish fan and means that you can allocate the calories from the fairly calorie dense fish sources to other health benefitting foods instead!
Vitamin D has been shown to play an important role in immunity regulating much of the immune response (in both the innate and acquired/adaptive systems). A deficiency in vitamin D has been associated with both increased inflammation and abnormal immune system function.
It's relevance in combating COVID-19 has very recently (as of April 2020) been brought to the forefront of research, with Irish researchers presenting its essential role in preventing respiratory infections, reducing antibiotic use, and supporting the immune system's response to infections. Achieving adequate dietary intake of vitamin D is extremely difficult and supplementation is a much more viable, inexpensive and effective alternative.
Zinc and selenium are two minerals that also play key roles in immune function, with deficiencies being attributed to a significantly decreased capability of our immune systems to battle against pathogens. Incorporating some beans and legumes, as well as nuts and seeds like squash and pumpkin seeds, as well as cashews, pine nuts, pecans and walnuts.
The mentioned nuts and seeds are also rich in vitamin E; an important dietary component in ensuring a healthy immune system and an optimal immune response. Not only is vitamin E a potent antioxidant but it may also increase the production (when required) of cells related to fighting off infection!
Other important lifestyle considerations to make our ensuring you're getting adequate sleep, exercise and managing your stress. When one or more of these falls to the wayside we can become more immuno-compromised.
We do hope this gives you all a bit more clarity on the subject of immunity and how to support and promote a strong immune system during these slightly more testing times. Remember to also maintain proper hygiene practices and use common sense; if you're sick stay at home, cover your mouth when coughing and wash your hands!