Our immune system is a remarkable thing. When it detects a foreign invader, swarms of fighter cells race to our defence. The invader is rapidly identified and appropriate antibodies deployed to take it down before it does too much damage. If the invader isn't immediately recognised as one we've experienced previously, our adaptive immune system will work out what it is and develop a new antibody accordingly. Then the next time we're reinfected with that particular pathogen, our innate immune system is ready for it! At least for a certain amount of time. Whilst some antibodies remain with us for life (mumps, measles, Chicken Pox etc), others unfortunately only last a few years.
That's in an ideal world ie a healthy body with normal innate and adaptive immune system functions.
Those foreign invaders that our innate immune system doesn't instantly recognise however can be particularly dangerous because they don't immediately invoke an immune response. It takes time (hours, days, or even weeks in some cases) for our adaptive immune system to figure it out and then develop the right antibody. In the meantime, the invader sets up shop and causes havoc. This can prove fatal, particularly if the invader manages to outrun or evade our immune system or for those with a compromised immune system.
Zoonotic diseases, which are viruses and bacteria that originate in other species, are a classic example of foreign invaders our innate immune system doesn't recognise. A 2012 report
for instance found that globally 56 (at that time) identified zoonotic diseases cause some 2,500,000,000 cases of sickness and 2,700,000 million deaths each year!
We pick up zoonotic diseases through interaction with their host species. Notable examples of zoonotic diseases include AIDS, anthrax, ebola, encephalitis, SARS (SARS-CoV-2, aka COVID-19 is a member of this group), MERS (camel flu), malaria, Ross River, Lyme disease, hepatitis E, lyssaviruses
(rabies etc), H1N1 (swine flu), avian flu, dengue fever, henipaviruses
) and many more
In many cases, the species to which these diseases 'belong' have either developed immunity to them, or they have 'special defence mechanisms' humans lack.
Bats for example carry an amazing number of viruses, some of which are amongst the most deadly zoonotic diseases to reach humans (ie ebola and Hendra). So why doesn't this high viral load at least make bats sick?
It comes down to a nifty mechanism called an interferon pathway
. All mammals, including humans, have one. It's part of our antiviral immune response system, and it gets switched 'on and off' as required. Research has found however that some bats have their interferon pathway permanently switched 'on'. This enables them to live with an elevated viral load without getting sick, or dying. In us though, and in most other species, having it permanently switched on would cause dangerously high levels of inflammation.
Bats have also developed anti-inflammatory mechanisms that protect them from such inflammatory damage. Scientists also think their relatively small size limits the level of inflammatory damage they sustain.
Will improving our immune system help reduce our susceptibility to zoonotic viruses like COVID-19?
Many things play into keeping our immune system healthy, or not. Paramount amongst these is our physical and mental health. The idea that our mental health plays a role in the health of our immune system was discounted for a long time. We now know though that the state of our mental and psychological well-being very much counts when it comes to having a healthy immune system.
Stress, Anxiety And Your Immune System
Many things can drag down our immune system and cause it to function less effectively than normal. Stress and anxiety notably are key culprits, and these are common amongst FIFO workers on mine camps. They cause the release of stress hormones (adrenaline and cortisol). These hormones are designed to protect us in life and death situations. They:
- ramp up our survival senses.
- put our heart, blood pressure, lungs and other organs vital for immediate survival on high alert.
- release more fuel (glucose) into the blood so we're primed for action. Our brain for example chews through extra fuel as it co-ordinates our defence responses and masterminds our survival plan.
In addition to the above, cortisol also increases the availability of tissue repairing compounds in anticipation of injuries during our fight or flight response.Cortisol And Your Immune System
Whilst all the above is going on other less critical functions, and functions that would impede our fight for survival, slow down. Generally, blood supply is diverted away from them to increase supply to systems vital to our immediate survival. Organs like skin and hair, our digestive system, reproductive organs, and even growth are all put on temporary hold at these times.
How Does The Body Defend Itself Against Infection
Cortisol also modifies our immune system responses. Under normal circumstances a bit of cortisol is beneficial for the immune system. Inflammation is caused naturally when lymphocytes (a type of white blood cell) charge to the rescue after invasive foreign substances are detected. It's not a bad thing, in moderation. Indeed, a degree of inflammation is an essential and normal part of your immune system response.
Too much inflammation on the other hand is bad news and this is where cortisol steps in. Cortisol helps keep inflammation under control by reducing the number of lymphocytes in the blood. Fewer lymphocytes = immune response suppression = less inflammation. It's a delicate balancing act designed to prevent our immune system from going on unchecked inflammatory rampages every time it detects invading antigens.
But – when we have high levels of cortisol constantly coursing through our system, which happens when we're continually stressed and anxious, our lymphocyte numbers are kept correspondingly low. Eventually this relentless unending suppression results in ongoing reduced immune function. We become immunosuppressed, and that creates all sorts of health problems including increased susceptibility to viruses and infections. Like COVID-19!
How is this relevant to mining? We've discussed mental health issues such as increased stress, anxiety and depression in remote and FIFO work environments, in previous articles. When workers are subjected to these types of health conditions for long periods, which is often the case in FIFO situations, they become prime targets for reduced immune function. And thus prime targets for viruses and infections. Like COVID-19!
Other Things That Can Weaken Your Immune System
Apart from stress and anxiety, there are many other ways our ability to cope with disease and infection is reduced. Again, many of these are common in FIFO and remote work environments. They include:
- Not enough sleep, or poor quality sleep – whilst you're sleeping your body takes care of many important functions, one of which is shoring up your immune system. Some essential immune system proteins for example are only produced when we're asleep.
- Not getting enough exercise – regular exercise is beneficial in so many ways. It improves blood circulation, which gets more nutrients and germ-fighting compounds pumping around your body.
- Not enough vitamin D – whilst this shouldn't be a concern for people who get enough sunlight, it may be a problem for shift workers during winter who work at night then spend most of their daylight hours sleeping. The good news is that there are dietary sources of vitamin D.
- Not enough sunlight – not only does not getting enough sunshine potentially increase your risk of a vitamin D deficiency, it may also apparently reduce the effectiveness of those all-important T-cells. T-cells are an integral part of your frontline immune response. They not only destroy infected cells but also send out signals that activate other immune system cells.
- Not eating enough fruit and vegetables – the many nutrients in these are vital for helping the body produce more white blood cells, fight inflammation, reduce oxidative stress and much more.
- Too much dietary fat – a diet too high in fats and oils can interfere with your white blood cell's ability to fight invading germs and other nasties. It can also lead to obesity, which causes a whole raft of health issues not the least of which is a reduced ability to fight off common viruses and infections like the flu.
- Some types of medications – drugs that are used to suppress the immune system (to treat certain autoimmune diseases for example), chemotherapy drugs, and TNF inhibitors can all reduce the effectiveness of your immune system.
- Nicotine – any type of nicotine addition (cigarettes, vaping, patches etc) can reduce your ability to fight germs.
- Vaping – health officials think chemicals in vaping liquids, apart from nicotine, may suppress immune system responsiveness when inhaled.
- Excessive alcohol consumption – every time you drink too much it takes your immune system 24 hours to recover its full capacity to protect you from germs. Long term the damage becomes more permanent, leaving you susceptible to a wide range of diseases and disorders.
What You Can Do To Help Your Immune System Help You
It's important that anyone who suffers from any of these issues, or works / lives in an environment where problems like stress, anxiety, depression, lack of exercise, alcohol, smoking, drugs and so on are commonplace, takes steps to mitigate them. Some of things you can do yourself to support your immune system and keep it healthy include:
- Get plenty of exercise – exercise releases endorphins, those 'feel good' hormones and helps you sleep better
- Get plenty of quality sleep – lack of sleep and poor quality sleep contributes to continual stress and anxiety, and potentially poor immune function
- Take up yoga – this is a traditional and time proven way to relax. Tai chi and other forms of martial art are likewise good for relaxation and stress relief.
- Meditate – as with yoga, meditation is commonly used to reduce stress and anxiety
- Listen to calming music – soothing music is a great mood enhancer and relaxer
- Practice mindfulness – it helps reduce the type of negative thinking that can contribute to anxiety
- Practice deep breathing – this helps slow your breathing, which reduces your heart rate, both of which are calming and good for reducing anxiety and stress
- Try progressive muscle relaxation aka deep relaxation techniques – this technique has been around since the early 1900's as a way of reducing stress
- Reduce caffeine intake – caffeine is a stimulant and can feed anxiety and stress, especially in large doses
- Reduce alcohol intake
- Stop smoking tobacco cigarettes
- Reduce processed sugar intake – processed sugar is bad news for health in so many ways
- Consider supplements – some types of supplements can help reduce stress; lemon balm, valerian, green tea, and omega 3 fatty acids have all been associated with relaxation
- Research appears to show that chewing gum is a good relaxant and can help reduce stress – apparently one of the ways it works is by enhancing blood flow to the brain
- Essential oils – some fragrances, like rose and lavender, are very relaxing and soothing; they're available in air diffusers and candles, two of the most popular ways to use them
- Read a good book – reading is an excellent way to immerse yourself in another world and forget about your current problems
- Pat your pet – the therapeutic value of pets is well known; they also provide uncomplicated companionship
- Try to improve or develop strong social contacts – interacting with other people, especially family and friends, is a great stress reliever
- Laughter is the best medicine – this is an oldie with more than a grain of truth when it comes to relieving stress and anxiety
- Get rid of those things in your life that are causing you stress, and that you're able to control
- Procrastination is a great way to get yourself stressed – prioritise what you need to do with a To Do List, set yourself realistic goals, and tick them off as they're achieved
Incidentally reverse zoonotic diseases, which are diseases and infections animals can pick up from humans, are also 'a thing'. They include:
- Influenza (a notable example of this was the H1N1 strain – YES, that's right; swine flu can be passed backwards and forwards between pigs and humans!)
- Methicillin-resistant Staphylococcus aureus (MRSA)