Generally speaking, when we’re stressed or under the weather we reach for comfort food rather than healthy food, and nowhere has that has been more apparent than during the recent Covid-19 outbreak. At no point did nutritious and health-giving wholefoods, veggies and fruit go out of stock on the supermarket shelves, but ready meals, frozen food, pasta and bread were all in short supply. As a Nutritional Therapist it completely baffled me, because a huge part of being a resilient human comes down to the strength of your immune system, and that can be hugely influenced by food.
Give it some guts
70-80% of your immune system lives in your gut, and we’d all do well to remember that every time we sit down to eat, or choose what to buy in the supermarket. It makes sense then, that gut health is a great place to start when you’re looking to support your immune system. Before I get into it, let’s recap how the immune system actually works:
How does the immune system work?
The immune system is constantly sampling molecules presented to it via the intestinal wall, and actually a lot of the time what it does is not react, i.e. do nothing. However, when we come under attack from a virus or something that really does have the potential to harm us, our immune system mounts a response to keep us safe. T cells and NK cells (Natural Killer cells…I love how scary they sound), hunt out and destroy viruses, and we also have other cool sounding immune cells called Macrophages, Dendritic cells and Cytokines to name a few. If a virus (extremely topical right now) or a pathogen makes it way through our first line of defence and comes into contact with one of the immune cells described above, then it should ideally be engulfed, destroyed, zapped and eradicated!
So why does our immune system sometimes get it wrong? Why do we get sick at all? Well in the case of viruses like Covid-19, the virus can actually mount a response, get rebuffed, but then come back looking like a different virus a week or so later so it’s a tough battle for the body to win. Generally speaking though, in order to be more resilient in general to everyday illnesses, we need to really start eating for our immune systems, which means eating to improve our gut health.
Short Chain Fatty Acids (SCFAs)
Our gut has many layers of defence, and the human immune system is one of the most complex things in biology – so much so that we still don’t really understand a lot of it, but that’s a topic for another time… One of these layers of defence is our commensal bacteria (i.e. your gut microbes), which take the fibre in our diet and ferment it to create Short Chain Fatty Acids (SCFAs), like butyric acid. These SCFAs have been studied extensively in relation to their extremely protective role against illnesses like Type 1 and Type 2 Diabetes, various different cancers, autoimmune conditions such as Crohn’s and Ulcerative Colitis and allergies – to name a few. So the more SCFAs we have, the healthier our gut and the stronger and more resilient our immune system.
Diversity is key
Really good gut health doesn’t come from taking a probiotic every morning, it comes from making an effort to eat a diverse range of plant based foods so that our gut bugs have a broad range of fibres to ferment and make SCFAs from. A great metric to keep on top of this is aiming to eat at least 30 different plant based foods per week. Spices and herbs count, so it’s actually not as hard as you might think. I encourage my patients to aim for 50 and to keep a tally on the fridge door to make it easier. Aim to ‘eat the rainbow’ every day and you can’t go wrong!
Here’s a short list of some of my top recommendations food wise for increasing and supporting your gut microbiome:
Yoghurt, kimchi, kefir, sauerkraut, tempeh, miso, kombucha…there are so many options. I like my patients to make their own sauerkraut or kimchi at home because you can ferment it to a level that contains loads of beneficial microbes and I often find that store bought kombucha or sauerkraut is fermented for flavour, rather than for the amount of bacteria it contains.
Fermented foods help to increase the diversity of our gut microbiome as they contain multiple strains of live, active bacteria, whereas in a probiotic you might just be getting one isolated strain.
Now, if you have a preexisting condition like IBS or IBD you might actually struggle with prebiotics (many of them are high in FODMAPs), but that doesn’t mean that you should avoid them forever – get yourself to a Nutritional Therapist to start trying to uncover the root cause of your digestive disorder so that you can build back in some diversity together over time. Prebiotics are like plant fertiliser but for your gut bugs – they provide an amazing substrate for them to ferment and make lots of SCFAs. Chicory, onions, garlic, asparagus, artichoke, leeks and dandelion greens are just some examples but a quick Google will give you a pretty comprehensive list.
Say no to sugar!
If fibre is the hero of the gut health and immune system scenario, then sugar is the complete opposite. Sugar has a detrimental effect on our gut flora and leads to poor immune health long term. Not only that but it wreaks havoc with our blood sugar levels and puts you at risk of conditions such as Type 2 Diabetes later on in life. Eating too much sugar feeds the ‘bad’ bacteria in our gut, and an overgrowth of bad bacteria spells disaster for you health wise. Keep sugar to a minimum (some fruit and natural sugars are fine), and your immune system will thank you for it!
How else can you boost your immunity?
When it comes to diet a lot of it is common sense: eat wholefoods, cook from scratch, avoid too much sugar and alcohol and make sure to include a diverse range of foods, not the same meals day in day out. But what about other ways to boost your immune system? Surely it’s not just about what we put into our bodies?
The unsung hero of the immunity question: Sleep!
Sleep your way to a stronger immune system
I mean, could it get any easier? Sleep is the number one way in which you can support your immune system, especially when you’re already under attack. Far too often these days we ‘push through,’ have another coffee and just get on with it – but that’s a sure fire way to burn out and leave yourself open for invasion by viruses, colds and flu. Sleep is the single most regenerative process known to man, and if you’re keen to be fit and healthy and live a long life then getting 8 hours every single night is fundamental.
Lastly, stress. When we’re in our fight or flight zone (our Sympathetic Nervous System), our bodies put a pause on all non-essential processes in order to focus all its time and energy on survival. Pretty much the only process that continue when we’re stressed are sending glucose to our muscles and brain, so we can make decisions quickly and run away if need be. A healthy immune system needs time in the Parasympathetic arm of your nervous system, the rest and digest phase, to do its job properly and protect us from invading pathogens. And yes, you guessed it, yoga is an incredibly well studied and documented way of tapping into this restful state. So get on the mat and find your zen, you’ll be fitter and healthier for it!
Grace Kingswell is a Functional Nutritional Therapist, Podcaster, Breathwork Coach and Auricular Acupuncturist living in Cornwall but seeing patients from all corners of the country via Zoom.
Find her on the Apple Podcasts App: State of Mind Podcast
On Instagram: @gracekingswell
Via her website: gracekingswell.com
Or on Patreon: Grace Kingswell