When it comes to immunity, I prefer to think about fostering immune resilience rather than boosting immunity? Why? Because, the consequences of an immune system that is operating without the proper regulation could be immune reactions against your own body tissues – autoimmunity – or excessive inflammation which could cause collateral damage, as has been seen with the so called ‘cytokine storm’ experienced by some COVID-19 patients.
Instead, immune resilience to me means that we are able to avoid infection in the first place; if we do get infected, we are able to launch a rapid and appropriate immune response to defend ourselves; and then once the threat has been neutralised we are able to calm down our immune system effectively.
The other think I like about the word ‘resilience’ is that you can have degrees of this. If you think that getting sick is a bit like falling into a ditch – the further away you are from that ditch the less likely you are to fall in, i.e. the more resilient you are. Any small steps you can take to move yourself away from the ditch are going to be beneficial – and so it is with health.
Our immune defences
If we think about respiratory infections specifically, our first defence against infection are the barriers between the outside world and our bodies – primarily the lining of our nasal cavities and our throat and lungs. These barriers are not only made up of a wall of cells that are meant to be tightly joined together, but also secretions of mucus (in the nose) or surfactant (in the lungs), secreted antimicrobial proteins and antibodies that can bind to disease-causing organisms; and a layer of resident bacteria and other microbes. Our nose also has hairs which can trap dust and bugs – which is why breathing through your nose is a wise move if you want to reduce your exposure in the first place.
If these barriers are breached, then our innate immune response is activated. This is a non-specific response, where various white blood cells are recruited to either gobble up bacteria or kill virally infected cells, and anti-viral proteins are produced. Alongside this, inflammation also kicks in. Inflammatory molecules signal to the brain to generate ‘sickness behaviour’ – including fatigue, depression, lack of appetite. As well as conserving energy which can then be used up by the immune system, this behaviour has an evolutionary basis: making us antisocial will stop us from spreading the illness to others. Inflammatory molecules also stimulate the production of more mucus – giving us a runny nose or a cough with the aim of expelling the pathogen – and a fever.
If we have not cleared the disease causing organism after 3-5 days then our adaptive immune response gets to work. This is a specific response against whatever has made us ill, and can involve antibodies or specialised immune cells that target cells infected with the particular virus.
Hopefully together these approaches remove the threat and then the whole thing can be switched off. The regulatory mechanisms that are involved at the end, also play a role throughout the immune response, to ensure that it doesn’t spiral out of control.
What then can we do to make sure that our immune system is operating optimally? There are lots of things to consider:
- Nutrition – are we getting adequate levels of all the nutrients needed to support the immune system in our diet, and can we absorb these? As well as vitamins and minerals, we need antioxidants from plant foods, healthy fats from oily fish, nuts and seeds, protein and sufficient energy.
- Sleep – sleep is needed not only to support repair of the barriers, but our immune system like many of our body systems works on a 24 hour rhythm tied to the day night cycle, so it helps to be in synch with this.
- Stress – this is a real biggie. Overall stress has a negative effect on immunity – and that does not have to be stress that we are aware of. Physiological stressors, like long-term infections or inflammation caused, for example, by food reactivity, non-optimal blood sugars or blood pressure, or lack of oxygen can also have similar effects.
- Barrier health – smoking or being exposed to air pollution can cause physical damage to the barriers, as can inflammation.
- Resident microbes – though it might seem odd, the bacteria living in our digestive tract can play a role in shaping the barriers elsewhere round our body. Healthy barriers need short-chain fatty acids to keep in good shape, and these are primarily made by our gut microbes when they are fed indigestible fibre (think vegetables, fruit and wholegrains).
If you are interested in hearing more about this and learning some practical steps that you can take to support you and your family, then why not watch my online masterclass?