Boosting Immunity or Building Resilience?

15 June 2020

The question on everyone's lips right now is “how can I boost my immune system”? While the idea of taking a “superfood”, medication or touted “immune boosting supplement” is enticing, the truth of the matter is it is not that straight forward, simple or indeed possible. In fact we do not want to boost a system that is in any way inflamed already (more on this in a moment). The immune system is precisely that — a system, not a single entity and as such is a highly complex web of specialist organs, cells, hormones and chemicals that ebb and flow in response to its surrounding environment. What we are actually striving for is an immune system that is resilient.  

A resilient immune system has: 

  1. The flexibility and capacity to adapt to any challenges (microbial, dietary, environmental) that are presented.
  2. The finesse to respond appropriately (not attack self as in autoimmunity)  and return to homeostasis – a healthy state of wellbeing with minimal collateral damage (tissue destruction or overwhelm). 

On the whole, our immune system does an outstanding job of defending us but sometimes it fails: a germ invades successfully and makes you sick, or there is a feed-forward cycle of unrelenting inflammation that overwhelms the system and dis-ease states begin to occur. What tips the balance in both these situations is a an already present state of chronic inflammation. I liken this to an inflammatory level threshold, the closer we become to this inflammatory threshold the less flexible our immune response and the greater is the likelihood to respond inappropriately and cause significant tissue destruction and damage. 

As my diagram here illustrates, lifestyle factors alone cause a rise in unrelenting inflammation that brings baseline very close to threshold. If your inflammatory burden is this close to threshold and overtime you experience a number of all these other triggers or inputs indicated in purple that further raises your inflammatory burden then it only takes one more “event” to reach threshold and immune resilience fails. 

Immune system resilience is about more than simply avoiding sickness. It’s about maintaining an inflammatory and immune response that is neither too passive nor too active, 24/7. A resilient response is the immune system responding in the right place at the right time, and is controlled. If we lose that resilience, then some sort of dis-ease occurs. 

Framed in this way, the holy grail of optimal health and wellbeing is to build and maintain a flexible and resilient immune system


What contributes to Immune Resilience?

1. Our food choices 

To mount an immune response is a highly energy demanding job,  we need a good supply of vitamins and minerals and balanced macronutrients: carbohydrate, fat, and protein. Excess sugar in the form of refined “package and promise” foods types (my worst is breakfast cereals) should be avoided. Sugar both disrupts the diversity of our gut microbiome which plays a vital role in the art of immune tolerance and also high blood sugar unleashes destructive molecules that interfere with the body's natural infection-control defences.

What to eat? Opt for real whole foods, especially vegetables and some fruit that are nutrient dense in polyphenols, active chemical compounds and vitamins and minerals which help protect cells from toxins and reduce inflammation in your body and improve diversity of the gut microbiome. Spices are a great source of polyphenols too so include more garlic, ginger, turmeric and cinnamon. Choose whole grain carbohydrates like wholegrain rice and older grain breads such as rye and spelt, avoiding overly processed wheat and package foods.

Think about protein as the side dish, rather than the main event and choose from fatty fish such as salmon, mackerel and sardines, eggs,  cheese, yoghurt , turkey, lamb and preferably organic beef and chicken. 

If you drink alcohol, drink only in moderation: 2-3 glasses of wine a week or a couple of gin and tonics. 

When to eat? eat 2-3 meals a day rather than snack and graze all day. Without even realising many of us are eating up to 16 hours a day. Leaving 4-5 hour gaps between meals or practising eating in an 8-hour window during the day reduces unnecessary inflammation. 

2. Optimise your vitamin D

This vitamin is so important for our immune system and overall health it’s being reclassified as a hormone! Vitamin D plays a key role in facilitating a balanced immune response - and helps to fight an infection like a virus. Although we do synthesise vitamin D ourselves -  it’s quite a process and the conditions need to be right: Vitamin D is formed in the skin from cholesterol (yes- you read that right!) after exposure to sunlight- specifically ultraviolet-B radiation (UVB), which enters the bloodstream and in the liver in made into to 25-hydroxyvitamin D (25(OH)D). This is the major circulating form of vitamin D and is used as a measure of vitamin D status. In the UK, and at similar latitudes, summer midday sunlight contains enough UVB for vitamin D synthesis while the weaker sunlight of winter provides a negligible amount of vitamin D synthesis. So getting out in the sunshine is helpful but it does need to be the correct UVB and in the UK.  Treat for vitamin D insufficiency if serum 25(OH)D levels are in the range of 25–50 nmol/L.

3. Get outside and move

Regular exercise is one of the pillars of healthy living. It improves cardiovascular health, lowers blood pressure, brings blood sugar under control by sensitising cells to insulin  and helps to control body weight. All of these conditions have inflammation at their very core, and so pushing you further towards that inflammatory threshold. 40 mins exercise of raising your heart rate 4-5 times a week is the goal. 

4. Look after your Gut Health

The different microorganisms, particularly the bacteria within the gut lumen, are producing chemicals that act on the host - these chemicals include, for example, the short-chain fatty acids (SCFAs) that are produced when bacteria in the gut consume non-digestible fibre for humans: SCFAs interact with the gut-associated immune system, an organised set of immune cells located under the gut lining all to our benefit. Eating in the way described about is the best way to promote diversity and immune tolerance. 

5. Improve Sleep Quality & Quantity

Science tells us that a lot of good things happen in our brains while we sleep. Learning and memories are consolidated and waste is removed, among other things. New research shows for the first time that important immune cells called microglia - which play an important role in reorganising the connections between nerve cells, fighting infections, and repairing damage - are also primarily active while we sleep. The findings, which appear in the journal Nature Neuroscience, have implications for brain plasticity, diseases like autism spectrum disorders, schizophrenia, and dementia, which arise when the brain's networks are not maintained properly, and the ability of the brain to fight off infection and repair the damage following a stroke or other traumatic injury. 

Adults generally require 7-8 hours sleep a night and teens 9-10 hours a night. I wrote a Blog here on tips for improving sleep.  

There are some supplemental nutrients and medications that of course bridge a nutrient gap or block an inflammatory pathway respectively which may be needed in some situations, but, the overriding message here my friends is that we cannot live a lifestyle of taking our built-in mechanisms for granted, akin to filling up your prize sports car with diesel rather than unleaded petrol and expect optional health and well being to be the result!  Look after yourselves and your immune resilience will take care of you well into your dotage! 

As always, in health,

Tanya x