The truth is that making savvier food choices at this time of year really can protect you from getting ill. And with cases of colds and flu predicted to soar — thanks to the lack of exposure to these bugs due to Covid lockdowns — this is now even more vital.
But if you thought the solution is to head for the latest (costly) superfood or supplement that promises super-immunity, the good news in these times of spiralling prices is that you really don’t need them.
That’s because our immunity is powered by the gut — and what our gut needs to function at its best is a diverse diet, alongside the other three key pillars: sleep, movement and less stress.
So starting today, and continuing tomorrow in the Mail on Sunday, I will be sharing the simple, cost-effective tweaks you can make to your autumn menus and day-to-day activities to bolster your immune defences.
DR MEGAN ROSSI: The truth is that making savvier food choices at this time of year really can protect you from getting ill
Happily, you will still be able to enjoy the delicious comfort food we tend to crave now the nights have drawn in, such as those warming bowls of pasta Bolognese or that Friday-night slice of pizza. For when it comes to an immune-nourishing diet, forget exclusion — it’s all about inclusion.
All you need to do is add some extra plant power to these choices; perhaps a can of lentils or some frozen vegetables to your pasta sauce, for example, or a bag of mixed leaves to your margherita pizza.
Add these heroes to your shop
These foods are filled with key nutrients and plant chemicals that will nourish your immune system (such as vitamins A, D and C; iron and zinc; fibre; and omega-3). So put them on your shopping list and aim to incorporate them into your weekly diet.
1. Walnuts
2. Garlic
3. Sun-exposed mushrooms (leaving them on a windowsill to absorb sunlight makes them a great source of vitamin D)
4. Firm tofu (this is different from silken tofu, which is delicious but lower in nutrients)
5. Carrots
6. Oranges
7. Wheat berries (the unprocessed form of wheat that you can find in most supermarkets. Cook them like you would barley grains)
8. Chia seeds
9. Turmeric (best combined with a few twists of black pepper to increase your body’s absorption of the anti-inflammatory active component called curcumin).
10. Broccoli
You can add garlic and oranges to your shopping list
Likewise, chocolate can still be on the menu (it’s certainly on mine), but add in prebiotics — types of indigestible fibre that act like fertiliser for our gut bacteria — such as those found in dried mango and pistachios.
By doing so, you will be increasing your intake of nutrients that are central to robust immunity.
This advice is not just based on what I see with clients, but is also backed by a wealth of research.
A major study published by my colleagues at King’s College London, which involved nearly 600,000 participants, found that people who ate a more varied diet full of plants had a 40 per cent lower risk of becoming unwell with Covid-19.
Plant-based diets (which aren’t necessarily plants-only) have also been shown to bolster our immunity against other viruses that cause colds and flu.
Diet has a vital role to play. And, better still, you can make key changes to your weekly shop without having to spend a fortune. A more diverse and plant-based diet will ensure you’re topped up with all the important micro-nutrients that you need for healthy immunity, such as vitamin C, zinc and omega-3.
The only supplement I’d broadly suggest taking is vitamin D. Most of us don’t get enough of it in the winter months in the UK, which is why the NHS recommends taking a supplement from October onwards (and all year round for those with darker skin), because the sun is not strong enough to stimulate our skin to make a sufficient amount of the vitamin.
Central to my plan is nourishing your gut. That’s because a striking 70 per cent of our immune cells actually reside in the gut, working alongside our gut microbes. For the most part, these have our back — as long as we feed and nurture them. Today, I will explain the key principles behind this gut-nourishing diet.
Then, tomorrow and on Monday in the Daily Mail, I will look at the three other pillars which are central to strong immunity: better sleep, less stress and more movement.
There will also be delicious recipes available exclusively on The Mail+, as well as easy food swaps to enhance your winter wellbeing to the max.
In the meantime, take my immunity and nutrition quizzes to check how ready your body is to fight off seasonal illness.
Repeat each quiz after a month of implementing your chosen strategies — fast-rising scores are a sure sign that your immunity levels are improving.
But first, let me explain just why your gut is so important to your ability to fight off infection…
YOUR GUT IS THE FIRST LINE OF DEFENCE
The immune system is made up of a complex, high-level network of cells, tissues and organs that work together to fight off invaders.
The 70 per cent of immune tissue that lies within our gut has a particularly important job, because our digestive tract is the most accessible gateway into the body.
It’s a pretty tough job, really. The gut immunity team is constantly on patrol, sifting through millions of foreign cells each day and discriminating between the harmless (such as friendly microbes) and potentially dangerous ones (for example, mycotoxins found in mouldy food and flu-causing viruses).
This immune tissue also keeps the rest of our cells in check by assessing old cells, which are more vulnerable to cancer-forming mutations, and deciding which ones should be made to retire.
The gut is the reason we’re not all bedridden and defeated by infection every time we eat or step outside.
Like all powerhouses, our body has two main lines of defence: our intestinal wall, which acts as a physical barrier to foreign invaders (like a bouncer at the door outside a club), and the more sophisticated and dynamic immune system (think security cameras, alarms and so on).
The wall of our intestine is made up of a barrier of cells — imagine a row of doors that are effectively secured by tight junctions. Our intestinal wall serves a dual purpose. Like the door and the bouncer who guards it, the wall allows the good guys (nutrients) to pass and keeps out the bad guys (pathogens).
However, these tight junctions can become weak, or loose, when we’re stressed; not getting enough plants in our diet; or have had one too many cocktails. As a result, unwanted nasties can sneak across the intestinal wall. Scientists call this intestinal hyperpermeability; a more user-friendly term is ‘leaky gut’.
Thankfully, even if a pathogen does make it through the first line of defence, our immune system is primed and waiting to pounce, triggering events both within and outside our gut to shut down any nasty invasions.
BE SURE TO FEED YOUR MICROBES
Prebiotic cookie dough drops
Makes 12
Raw cookie dough is full of nostalgic childhood memories of baking with my granny, so I wanted to recreate it with a version that I could also share with my gut microbes.
This is a perfect afternoon pick-me-up, or an ideal treat for a movie night, boasting 4.25 plant points in every ball. Try it dotted into ice cream. It will keep for up to a week in the fridge, or in the freezer for up to a month.
½ x 400g tin of chickpeas, drained and rinsed twice
80g cashew butter, or nut or seed butter of choice
1 tsp vanilla extract
3 tbsp ground almonds
5 Medjool dates, pitted and roughly chopped
35g dark chocolate chips, roughly chopped
80g chocolate of choice for coating (optional)
Place the chickpeas, nut butter, vanilla extract, ground almonds and dates in a food processor and blitz for 1 to 2 minutes into a thick paste. It usually makes a big ball of dough.
If the mix is a little dry, add water to help it blend (a bit at a time, up to 1 tbsp). Stir in the chocolate chips.
Split the dough into 12 even pieces and roll into balls. Place them on a tray lined with a piece of non-stick baking paper and chill in the fridge while you melt the chocolate (if using).
Break the chocolate into pieces and put in a heatproof mixing bowl. Melt by placing over a saucepan of simmering water or heating in the microwave in 30-second bursts. Decorate the drops with as much chocolate as you like – dunk fully, drizzle or pour a spoonful over.
How to make prebiotic cookie dough drops
The real secret weapon in our body’s defence system is the colony of microbes living in our gut, known as our gut microbiota. Without them, our immune system would, frankly, be pretty weak.
Helpful microbes line the entire digestive tract, from the mouth (where they work with enzymes in the saliva to start the digestive process), right through to the acidic stomach and the length of the small and large intestines.
They closely monitor everything you eat and drink, neutralising toxins and germs before they can do too much damage.
Importantly, these microbes raise signals for the immune system to respond if necessary. They’re also in charge of ‘training’ our immune system so it can better protect us.
More specifically, gut microbes teach our immune system what is worth reacting to and what is safe.
This is why, if your gut microbes are imbalanced — with too many ‘bad’ microbes — you can end up with a poorly trained immune system that overreacts to innocent bystanders (cue allergies and autoimmune conditions, where proteins in food such as peanuts are mistaken for the enemy) and underreacts to the real bad guys (giving a free pass to cold and flu-causing viruses).
Without our gut microbiota, our immune system would be pretty inefficient — think amateur athlete versus elite athlete. I know who I’d rather have on my side.
We also need a healthy population of gut microbes to help us break down and digest our food so that the immunity-enhancing nutrients in each meal can be released into the bloodstream. And, in return for feeding them, these microbes have a clever sideline in producing ‘postbiotics’ — byproducts of digestion that play a significant role in gut and immune health.
For instance, postbiotics trigger signals that dial down inflammation, reducing the unpleasant symptoms we experience when we’re ill (inflammation, which causes a high temperature, is the body’s way of helping to kill off viruses), and activating healing by fuelling cell repair.
Generally speaking, the more diverse your gut microbes, the greater the breadth of skills the ‘team’ possesses — and the better your overall health. This likely explains why people with lower immunity tend to have a less diverse community of gut microbes, according to a study published in the journal Nature by researchers from Harvard Medical School.
So, one of the best ways we can support our immunity is by supporting our gut microbes and keeping our diet diverse and plant-based.
As I alluded to earlier, plant-based doesn’t have to mean plants-only.
In fact, we know meat and fish can be hugely beneficial for our gut and immunity.
Take oily fish, for example — it’s one of the best sources of immunity-nourishing and inflammation-quenching omega-3 fatty acids.
MAKE THE SUPER SIX YOUR CORNERSTONE
Thanks to the fibre, prebiotics and polyphenols (plant chemicals) they contain, there is no question that plants are our microbes’ favourite food.
But increasing the plant-based foods in your diet is as much about quality as quantity.
Highly processed plant foods that have been stripped of their wholefood goodness, such as refined grains and cereals, ultra-processed vegan burgers and pastries, fruit juices, and concentrated sugars such as jams, agave, honey and syrups, will not support your gut microbes.
What you need to focus on instead, as the core of any eating plan, is what I call The Super Six: wholegrains, fruits, vegetables, nuts and seeds, legumes (beans and pulses), and herbs and spices.
Each of these plant food groups provides your body and your gut bacteria with the different fertilisers they want and need.
With a few tweaks to your favourite meals you can teach your whole family to eat more plants — even if it means sneaking them into their dinners initially, until the microbes in their mouth work their magic and change their flavour preferences. Research shows that it can take as little as two weeks to retrain our tastebuds.
Doing so will help your gut microbiota to thrive, and when your gut microbes are more in balance, you don’t just have a more resilient immune system — it’s good news for your skin, heart, hormones and brain, too.
Extracted from Eat Yourself Healthy by Megan Rossi (published by Penguin Life at £16.99. Text © Megan Rossi, 2019. Photography © Emma Croman, 2019) and Eat More, Live Well by Megan Rossi (published by Penguin Life at £16.99. Text © Megan Rossi, 2021. Photography © Andrew Burton, 2021).
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