How to boost your immunity to infection

How to boost your immunity to infection

21 April 2021

Dr Monique Hope-Ross and Dr Paul B Chell

Immunity is your body’s defence against foreign invaders. Consider your immune system like an army. It is there to defend you, but occasionally, it can be overwhelmed. It can also fail, and it can even turn on you.

The Covid-19 pandemic showed how important the immune system is; some infected people remained well, whilst others were struck down. The single most important factor is how well your immune system copes with the virus. And you, like many other people, may have thought about boosting your immunity. You can give yourself, your family and friends the best possible protection against serious Covid-19 infection.

Gut Bugs
Figure 1.

Gut bugs are composed of 38 trillion microorganisms, which include bacteria, viruses and fungi. They are highly interdependent, there are hundreds of different species and in health, the good bugs keep the bad bugs in check.

The gut microbiome

Healthy and diverse gut bugs, (the gut microbiome) are critical to a well-functioning immune system 1. Your immune system, and your health and depend on this colony in your gut 2. There are an immense number of gut bugs: 38 trillion of them, which is more than the 31 trillion cells in our body; so just think about it, we are out-numbered, and by bugs! To nurture healthy gut bugs, we need to nurture healthy habits. If you look after your gut bugs well, you will reap massive rewards, because in so many ways, they will look after you.

Firstly, you need to feed your gut bugs. They thrive on indigestible plant residue, known as dietary fibre, that end up in your large bowel, where the majority of your gut bugs reside. They like a variety of different types of fibre, and this supports a good species mix within the bug community. A healthy diet is the key, with lots of plants, in particular green vegetables such a cabbage, kale, leeks, spinach and broccoli.

Highly processed food and super-refined carbohydrates do the exact opposite; they harm your gut bugs. Inflammation results, from your immune system trying to counteract sugary processed foods, you were simply not designed to eat. Over time, bad bugs gain the upper hand, at the expense of good bugs, causing your health and immunity to suffer.

Super-refined carbohydrates such as biscuits, sweets, pastries and cakes are the usual culprits. Long-term (chronic) inflammation results, leading to diseases such as high blood pressure, high cholesterol and diabetes. As your metabolism goes awry, this then starts piling on the pounds. So, either give up the sugary foods completely, or make them a very rare treat. Just like cigarettes, you become addicted and have to treat it as seriously. Sugary and processed foods are designed to get you hooked as a child. And remember carbonated sodas and fruit juices are just another form of this harmful junk. You want an orange; great, eat it. Just cut out the juicing that destroys the vital fibre, and makes it just as bad as any carbonated drink! Super-refined carbs lead to insulin resistance, which is also a factor in poor outcomes to covid infection.

Figure 2. Kefir: Grains (left) and milk.

Kefir is a fermented milk drink, which has been drunk for thousands of years. Originating in the Caucasus mountains, the Ossetians considered it to have magical properties; kefir grains (they are not real grains, but a name for the lumps of bacteria) were considered to be part of the family’s wealth and were passed on from generation to generation.

Probiotics foods such as fermented vegetables, live yoghurts and cheeses, kefir and kombucha provide live healthy bacteria that support your gut bug colony.

Try not to kill your gut bugs with antibiotics. ‘Anti’ means against and ‘biotic’ means a living thing. Many of your gut bugs don’t survive an antibiotic onslaught. Following a course of powerful antibiotics, your gut bugs can take up to 9 months to recover, if at all, and they may never recover fully. Our mantra in whisperer HQ is to take antibiotics, only if you have a serious illness. If you do have to take antibiotics, then you need to do an intensive gut bug recovery programme, which we deal with in another blog.

Your gut bugs like a run! Remember, they do better when you are fit, so exercise is important for healthy gut bugs. Getting out in the open and spending time outdoors also helps your gut bugs: they like to be taken for a walk, and it increases the resilience of your gut bug community. And, they do better when you have routines, then they can sleep when you do! 3

Maintenance and repair of the immune system

To build up your immunity, you need to have the building blocks to make the pillars of the immune system-T cells, B cells and antibodies. For this, your diet has to provide the essential ingredients-protein, minerals and vitamins. As your body cannot manufacture minerals and vitamins-these must be supplied by your food. Of course, all vitamins play a role in immunity, but some are more important than others. Vitamin A and D take centre stage, but most people are not deficient in Vitamin A.

Worryingly, a huge proportion of the world’s population is deficient in Vitamin D, particularly in the Northern hemisphere, where 50% of people have low Vitamin D 4. Many health authorities recommend universal supplementation with Vitamin D in the winter months. The maximum recommended daily dose is 4000IU (100mg).

Vitamin D is one of the most critical vitamins for proper functioning of your immune system. Numerous reports showed that higher levels of Vitamin D were associated with lower levels of Covid-19 infection. We saw in Covid-19 that low vitamin D predisposed to the development of infection, that low vitamin D was associated with serious disease, that low vitamin D was associated with death and lastly that high dose vitamin D had some benefit in serious infection.

A strict vegan diet may lack iron and B vitamins and supplementation should be considered.


Cortisol helps us to get through acute stresses, but too much, for too long is not so good. Persistently elevated cortisol depresses the immune system, and you can become very ill because of this, with persistent infections amongst other problems 5. Modern life is full of stressful situations, but the key is how we manage our stresses. Managing stress effectively is the key to reducing persistently elevated cortisol. Stress management with meditation or other relaxation techniques will help to protect your immune system.

Circadian rhythm

Humans evolved for millennia, under the light and dark cycle of the Earth, generated by its 24-hour rotation and its orbit around the sun. We rise, work and sleep with the sun; or rather we did. Sometimes it is helpful to reflect on how we evolved. Our body clocks are tied to this daily rhythm and our health and immunity is dependent on this rhythm. Changing our rhythm sends our body haywire, increasing inflammation, disrupting our T-cells, B-cells and antibodies. Respecting this rhythm helps to keep us healthy 6. Shift workers bear the brunt of our societal demands and suffer poor long-term health, in addition to more colds and flu than the general population 7.

Sleep is much more than a passive process; sleeping is the time when bodily repair and regeneration go into overdrive 8. Both the quality and quantity of sleep is important. It needs to be of sufficient quality to support and replenish a healthy immune system 9. And of sufficient quantity to allow this to happen; an ideal goal is to sleep 7 hours a night.

Cold water boosts immunity
Figure 3. Cold water boosts immunity


Cold water boosts immunity to infection and may also help people with chronic inflammation 10. We have heard a lot about the inflammatory cytokine storm seen with Covid-19 and cold water reduces these inflammatory cytokines, while boosting the anti-inflammatory chemicals. Sea swimming is probably not for everyone, but a cold shower in the morning will do the trick. Remember, if you’re new to this, build up slowly, giving your body time to adapt.

Figure 4. Cold water boosts immunity

Blog whisperings: supporting your immune system against all infection including covid-19

  • Support your gut microbiome; high fibre diet, avoid refined carbohydrates, exercise and spend time outdoors
  • Antibiotics must ONLY be used for serious illness
  • Eat probiotics-Kefir, fermented vegetables, live yoghurt and kombucha
  • If your diet is restrictive, consider iron and vitamin B supplements
  • Take vitamin D: daily dose is 1000IU-4000IU(25-100mg)
  • Manage stress effectively with relaxation techniques or meditation
  • Respect your body clock and try to build a daily rhythm into your life
  • Sleep well and for long enough (7 hours)
  • Cryotherapy: Cold showers, ice bath or sea swimming

Please read:

The information on this website is not intended to constitute medical advice, nor is it intended to replace or conflict with the advice given to you by your doctor or other health professional. Before embarking on the plans set out on this website, you should discuss them with your doctor, especially if you have any medical condition or if you are taking any medication. The author and publisher disclaim any liability directly or indirectly from the use of the material in our books and on our website by any person.

Was this article useful?

Please share it with your friends to help us spread the word about the Whisperer.

More from the Diet Whisperer

Weight Loss Coffee, Fact or Fiction?
Weight Loss Coffee, Fact or Fiction?

Every day, we drink over 2 billion cups of coffee, the world’s favourite drink! Originating in Ethiopia, coffee is one of the most important commodities in the world. It is grown worldwide throughout the ‘Bean Belt’; the area surrounding the equator between the tropics of Capricorn and Cancer.

Read Article
Can Apple Cider Vinegar help with Weight Loss?
Can Apple Cider Vinegar help with Weight Loss?

Apple cider vinegar has a long pedigree, shrouded in mystery; a folklore remedy found in many cultures from the Babylonians to the Aryans to Samurai warriors, who used it for strength and power. More than 2,000 years ago, Hippocrates recognised its value as an antiseptic, and latterly, apple cider vinegar was used to treat wounds in the battle fields of WW1 and the US civil war. In recent years, people have explored its use in heart health, weight loss and diabetes.

Read Article
Why oxytocin matters
Why oxytocin matters

We evolved to live in social groups and evolution endowed us with genes and chemicals such as oxytocin to keep us that way. Oxytocin influences our behaviours and our health. Found throughout the animal kingdom, it has been with us for a staggering 100 million years. Oxytocin helps us to meet our social needs by cementing and supporting our relationships, our deep interpersonal and social bonds.

Read Article

Enjoying the whisperer?

Why not subscribe to our monthly newsletter and get free tips and tricks about how to lose fat quickly and keep it off forever.


We exist to help you.


We're here to share information about how to lose weight quickly, become healthier and leaner, stay lean, feel better and live longer. The Diet Whisperer Foundation is our sister charity that uses money from our book sales and helps the least able in our society to escape obesity and ill health.

The information on this website is not intended to constitute medical advice, nor is it intended to replace or conflict with the advice given to you by your doctor or other health professional. Before embarking on the plans set out on this website, you should discuss them with your doctor, especially if you have any medical condition or if you are taking any medication. The author and publisher disclaim any liability directly or indirectly from the use of the material in our books and on our website by any person.

Copyright © 2020 MediaMedica Ltd 12588057.
All rights reserved.

The moral right of MediaMedica Ltd to be identified as the author of this work has been asserted in accordance with the Copyright, Designs and Patents Act 1988.

No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical photocopying, recording or otherwise without the prior permission of the copyright owner.