We’re used to hearing how certain supplements will ‘boost’ our immunity — and are encouraged to think that taking tablets can easily transform us into common-cold-kicking super humans.
But the reality is that our vast, interconnected immune system is too sophisticated to simply respond to one element such as Echinacea or zinc.
Instead, we need to examine a number of different ways in which food and lifestyle choices can ensure our immune systems function in peak condition — and keep us in good health.
We need resilient immunity to defend us against infective organisms, such as bacteria and viruses, and also to identify and clear away mutated or malfunctioning cells that could, for instance, lead to inflammation and even tumours.
We’ve already seen how food can be as powerful as pills in protecting us against a variety of diseases from diabetes to mental health problems and from osteoporosis to heart disease.
Today, as we conclude our series based on my new book Eat To Beat Illness, we’ll examine how crucial nutrition and healthy living habits are to our precious immune systems.
There are certain sites in the body where immune cells interact with each other and are developed — such as your bone marrow, the spleen in your abdomen and lymph nodes in the neck, armpits and groin.
However, one particularly important area is our digestive system and, overleaf, we’ll see why the food we eat plays a vital role in helping us to fight infection.
I’m a NHS doctor trained in conventional medicine, but I’m also living proof of the importance of diet as well as drugs, having made a series of lifestyle changes to cure my own irregular, fast heartbeat eight years ago instead of opting straight away for the surgery recommended by cardiologists.
In the process, I learned to love cooking, too — so my second passion is sharing delicious dishes from around the world so you can see for yourself how exciting healthy food can be.
In today’s recipes, I’ll show you some of my mouthwatering favourites aimed at providing key nutrients for our immune systems. Your taste buds will thank you for trying them, too!
Pea orecchiette with purple sprouting broccoli & hazelnuts
Pasta is one of my favourite foods. Over the past few years, ‘carb bashing’ has demonised pasta, so it’s no longer thought of as a healthy option, but I believe it’s about balance.
Wholewheat pastas are good higher-fibre options, but even white pasta on occasion is something to enjoy. The focus in this recipe is on delicious greens that accompany the pasta; the protein-packed peas and vibrant purple broccoli pair really well with the salty Parmesan and sharp lemon zest.
- 150g wholewheat orecchiette pasta
- 3 tbsp extra-virgin olive oil
- 4 small garlic cloves, finely chopped
- 1 small red chilli, deseeded and finely chopped
- 200g purple sprouting broccoli (or Tenderstem)
- 200g garden peas (fresh or frozen)
- Grated zest of ½ lemon
- 10g Parmesan cheese, grated (optional)
- 20g raw hazelnuts
- Sea salt and freshly ground black pepper
The focus in this recipe is on delicious greens that accompany the pasta; the protein-packed peas and vibrant purple broccoli pair really well with the salty Parmesan and sharp lemon zest
Bring a saucepan of salted water to the boil. Add the pasta and cook it for 2 minutes less than the packet instructions advise. Meanwhile, heat the olive oil in a large frying pan over a medium heat, add the garlic and saute for a minute, then add the chilli, broccoli and salt and pepper, cover and cook for 4-5 minutes.
Drain the pasta, reserving 50ml of the pasta cooking water, and add the pasta and water to the pan of broccoli, along with the peas. Cook for a further 2-3 minutes, then add the lemon zest and Parmesan (if using) and remove from the heat.
Lightly toast the hazelnuts in a separate dry frying pan over a medium heat for 1-2 minutes, then roughly chop and scatter them over the pasta at the table
DOCTOR’S ORDERS: You can use any wholewheat (or even gluten-free) pasta in this recipe. To make the dish vegan, swap the Parmesan for nutritional yeast flakes, which will give a similar umami taste without the dairy.
A healthy gut is key
The gut is a particularly important area for our immune system, as a very high proportion of immune cells is contained in our digestive tract.
They are engaged in the constant and crucial job of preventing harmful and dangerous substances from entering the blood stream, while allowing all the important healthy processes of digestion to take place.
Having a robust and well-functioning gut population protects and bolsters our ability to deal with infections on several levels. These microbes attack harmful bacteria, release micronutrients to support our own bacteria and combat inflammation — this, in turn, reduces our risk of developing diabetes and heart disease.
Sometimes our immune cells can mistakenly identify normal human cells as foreign and send signals to attack them as if they were infections. There are more than 80 different auto-immune conditions affecting various parts of the body and the causes are still being studied. Doctors typically prescribe corticosteroids or other drugs to dampen down the body’s immune response.
It is also known that those suffering from auto-immune conditions such as psoriasis and rheumatoid arthritis tend to have imbalances in their gut populations. It’s clearly a complicated topic, but ensuring a healthy and thriving gut population using the right foods could be a good starting point for those suffering from auto-immune conditions. Many well-respected scientists agree with this.
SUGAR AND STRESS
In recent years, we’ve begun to recognise the importance of a component of our cells called mitochondria. These are found in all of our cells and have been traditionally referred to as ‘powerhouses’ because they operate like batteries, providing energy for all normal cell functions.
But healthy mitochondria are also vital for a robust immune system — so providing them with correct fuel is essential. It’s known that high-sugar diets and stress can damage mitochondria, which goes some way to explaining why poor diets and mental pressure appear to have damaging effects on our immunity.
THE KEY FOODS
Selecting exactly which foods to eat to best support your immunity is a difficult topic to tackle precisely because it’s not yet been covered by scientific research in the way that numerous papers have studied the links between diet and heart disease or diabetes.
Nonetheless, my suggestions follow the ethos of my programme: to give you reasonable, evidence-based suggestions, sprinkled with a good dose of common sense, so that you can make up your own mind about how your lifestyle could help you to live a healthier, happier life.
These delicious ingredients and recipes will help to focus on how vital it is to keep your immune system in peak condition.
Bright orange and yellow-coloured foods, including winter squash and sweet potato, and dark greens such as kale, contain plant chemicals called carotenoids, which are essential for our immune systems and also for maintaining the health of our guts.
Carotenoids are antioxidants, preventing cells from damage, that also have the capacity to be converted into vitamin A, which is very important for keeping the immune system in good order and also in helping to maintain good eye health.
Greens such as broccoli, parsley, spring greens and Brussels sprouts are also key ingredients. These contain good supplies of vitamin C, also important for immunity.
Many of my patients have been swayed by advertisements on vitamin C supplements and immunity, but I prefer to recommend whole foods over supplements because of the abundance of other vital micronutrients they contain.
NUTS AND SEEDS
Nuts such as Brazils, cashews and almonds, as well as sunflower seeds and flaxseed, all contain good sources of zinc, selenium and vitamin E.
All three have been shown to have positive results on immune health in clinical trials — which is why they’re labelled ‘immune boosting’ in many stores. However, I don’t believe this is justified given that the quantities used in trials would mean that most people would have to eat unfeasible amounts to see those results.
Instead, I would urge you to include nuts and seeds in your diet because they are fantastic for your all-round health and also contribute to immune health.
Improving gut health is an excellent way to boost our immune systems. Plant proteins are a particularly good way of achieving this, as the fibre they also contain is important for reducing inflammation. Look out for chicory, endive, Jerusalem artichoke and garlic as, when digested, these make a fatty acid chemical called butyrate that helps to maintain the lining of the gut wall.
HERBS AND SPICES
Ginger, turmeric, fennel and some botanicals, such as peppermint, may have a role in immune support, as they have been shown in some small studies to reduce gut inflammation.
I believe that regularly using spices and herbs for their taste as well as their health-giving properties is something we should all embrace.
Although there is a tradition of using different herbs, including Echinacea, elderberry and mushroom varieties, for immune support in many cultures, I would rather we all focus on accessible diet and lifestyle strategies than relying on extracts of a particular flower or fungus.
Try my delicious thyme and ginger comfort soup for a tangy and wintery way to help your health and your immune system.
Thyme & ginger soup
I always recommend broths and soups for patients and colleagues during a viral illness such as the flu. Soups are a great way to introduce micronutrients to support your body’s defences when you’re not feeling strong enough to make a complicated meal or you lack appetite.
My inclination is always to make a turmeric and chilli ‘medicinal broth’ like the one in my first book, however it’s not always to everyone’s taste.
This is a more lightly spiced version, with thyme and ginger as the central antiviral ingredients. You’ll love the mellow flavours in this and it’s sure to comfort when you’re feeling poorly.
Soups are a great way to introduce micronutrients to support your body’s defences when you’re not feeling strong enough to make a complicated meal or you lack appetite
- 2 tbsp coconut oil
- 6 garlic cloves, peeled
- 10cm piece of root ginger, peeled and grated, plus extra to serve
- 2 tsp ras el hanout (North African spice), plus extra to serve
- 200g new potatoes, scrubbed
- 200g carrots, scrubbed and roughly chopped
- 100g dry sun-dried tomatoes (not in oil) or use fresh tomatoes
- 25g thyme stalks, tied together with string, plus extra leaves to serve
- 1 bay leaf
- 1.2 litres boiling water
- 100g spinach, roughly chopped
Melt the coconut oil in a large saucepan over a medium heat. Add the garlic and ginger and saute for 2 minutes until lightly browned, then add the spice blend, potatoes, carrots, sun-dried tomatoes, bunch of thyme and bay leaf, stirring for a few minutes to marry the flavours in the oil.
Pour in 1 litre of the boiling water, cover and simmer for 20 minutes until the potatoes and carrots are soft. Take off the heat, remove the thyme bunch and bay leaf and add the spinach and the remaining 200ml water. Cover and cook for a further 2 minutes to wilt the greens.
Serve the soup as a consomme or blend the ingredients with a stick blender until the soup has a smooth consistency. Divide the soup among bowls and garnish with a dash of the ras el hanout, freshly grated ginger and extra thyme leaves.
DOCTOR’S ORDERS: Swap the carrots and potatoes for peeled butternut squash, parsnips or swede, or a combination of these. Avoid seasoning the dish, as the dry sun-dried tomatoes tend to be quite salty.
Fennel sardines with pine nuts
Sardines are fantastic — they are cheap and a good source of long-chain omega-3 fatty acids that are brilliant for brain health. You can use other oily fish, but this is my favourite.
They’re a staple in the Mediterranean and so-called MIND diets, which have been shown to reduce the likelihood of cognitive decline. Adding herbs and greens to the dish creates a nutrient-dense, inflammation-lowering, delicious recipe.
SERVES 2 OR 4 AS A SIDE
- 150g skin-on new potatoes, quartered
- 2 tbsp extra-virgin olive oil
- 1 white onion, thinly sliced
- 1 fennel bulb, thinly shaved, fronds reserved and chopped
- 1 tsp fennel seeds
- ½ tsp dried chilli flakes
- 200g fresh sardines (or unsalted tinned sardines in oil, drained)
- 100g spinach, finely chopped
- Grated zest and juice of 1 1emon
- 25g toasted pine nuts
- Sea salt and freshly ground black pepper
Sardines are fantastic — they are cheap and a good source of long-chain omega-3 fatty acids that are brilliant for brain health
Place the quartered new potatoes in cold salted water, bring to the boil and simmer for 7-8 minutes until tender, then drain and set aside. Heat the olive oil in a large frying pan over a medium heat, add the onion and shaved fennel and saute for 4-5 minutes until softened, then add the fennel seeds and chilli and cook for 1 minute.
Finally, move the vegetables to the edges and add the fish (skin side down) with some seasoning to the centre of the pan and cook for 3-4 minutes.
Add the spinach and potatoes to the same pan and stir through the vegetables to coat in the spices, flipping the fish to cook on the other side for 1 minute. Finish with the lemon juice and zest, pine nuts and fennel fronds.
DOCTOR’S ORDERS: For a plant-based version of this dish, swap sardines for cannellini beans.
Ethiopian berbere curry
This delicious curry is inspired by Ethiopian cuisine and uses a spice blend called berbere. I would describe it as a spicy masala — it has a fantastic heat to it.
It tastes phenomenal with the mangetout and greens, but you could use any vegetables you have to hand. I learned the trick of adding nut butter to rice from a young Zimbabwean chef who told me it was a staple in his country’s cuisine. It adds protein to the wholegrain rice and tastes wonderful with this curry.
- 250g red Camargue rice, soaked in water for at least 20 minutes, then drained
- 2 tbsp coconut oil
- 2 red onions, thinly sliced into half-moons
- 3 tsp berbere spice blend (or see tip)
- 100g baby tomatoes, halved
- 100g peas (fresh or thawed)
- 200g mangetout
- 150g broccoli, broken into 3cm florets
- 400g tin chopped tomatoes
- 400g tin coconut milk
- 350ml vegetable stock
- 1 tbsp peanut butter (smooth or crunchy)
- 25g fresh coriander, finely chopped
This delicious curry is inspired by Ethiopian cuisine and uses a spice blend called berbere. I would describe it as a spicy masala — it has a fantastic heat to it
Melt the oil in a large saucepan over a medium heat, then add the onions with the spice blend and cook for 2 minutes, stirring. Add the baby tomatoes and cook for a further minute. Toss in the peas, mangetout and broccoli florets, stirring to coat them in the spices, then add the chopped tomatoes and coconut milk. Bring to a simmer and cook for 10 minutes while you cook the rice.
Tip the rice into a dry saucepan over a medium heat. Cook the grains for 1-2 minutes until they are dry and smell toasted, then add the vegetable stock and peanut butter, stir, cover and simmer for 15 minutes until the rice has absorbed the water and the grains are cooked.
Stir most of the chopped coriander into the curry and scatter the rest on top of the rice as a garnish, before serving.
DOCTOR’S ORDERS: You can find berbere spice blend in most supermarkets, but Jamaican jerk spice can work well as a substitute.
Roasted squash curry with cashew sauce
Curry dishes can be the healthiest and most comforting dishes to make. Ginger, garlic and onion, the typical base ingredients for a curry, are a powerful trio that have all been shown to have anti-inflammatory properties and may have a role in improving the resilience of our immune system. The wealth of spices used in curries gives them so much flavour and this is one of the quickest dishes to make. Serve with wholemeal chapatis, brown rice or simply on its own.
- 500g unpeeled acorn or butternut squash, cut into 3cm-thick wedges, seeds removed
- 150g unsalted cashews
- Sea salt and freshly ground black pepper
- 1 tbsp coconut oil
- ½ large white onion, diced
- 4 garlic cloves, grated
- 15g root ginger, peeled and grated
- 2 tsp garam masala
- 1 green chilli, halved and deseeded
- 250g baby tomatoes diced, or 400g tin chopped tomatoes
- 2 tsp tomato puree
- 50g spinach, finely chopped
- 10g fresh coriander leaves, finely chopped, to serve
For the cashew sauce
- 2 tsp smooth cashew butter
- 1 tsp ground cumin
- Juice of ½ lemon
- 50ml hot water
For the masala marinade
- 2 tbsp coconut oil, melted
- 1 tsp garam masala
- 1 tsp maple syrup
- 1 tsp ground turmeric
Curry dishes can be the healthiest and most comforting dishes to make. Ginger, garlic and onion are a powerful trio that have all been shown to have anti-inflammatory properties
Preheat the oven to 200c/180c fan/gas 6. Mix the marinade ingredients together in a small bowl. Spread the squash pieces over a baking tray with the cashews and coat with the masala marinade and sprinkle with salt and pepper. Bake for 20-25 minutes, stirring occasionally so the cashews don’t bum, until the squash is cooked through and the cashews are lightly browned.
Meanwhile, heat the coconut oil in a large frying pan over a low-medium heat. Add the onion, garlic and ginger and cook for 2 minutes, then add the garam masala, green chilli, tomatoes and tomato puree. Season with salt and pepper and cook for 6-8 minutes, allowing the tomatoes to break down. Add the roasted squash, cashews and spinach to the mixture and stir for 2-3 minutes to coat them in the sauce.
Whisk the cashew sauce ingredients in a bowl to make a light creamy sauce. Dress the curry with the sauce and finish by scattering over the chopped coriander.
Dr Rupy’s health habits
Nutrition has a huge role to play in immunity, but the complexities of this particular system demonstrate why the combination of a variety of lifestyle factors, including exercise and sleep, is the best way forward.
Regular, moderate exercise has been universally shown to be beneficial to immunity. Aerobic exercise encourages your body to be more resilient to causes of stress and can also improve your mitochondrial function.
Over-training, however, is associated with reduced immunity.
GIVE YOGA A GO
Studies show yoga can have positive effects on immunity by improving cell function. The benefits are such that yoga could be one of the best immune-promoting activities known.
The gradual deterioration of our immune system as we age can be closely related to both psychological issues and stress hormones. So it’s clear that techniques — such as meditation or breathing exercises — with demonstrated capacity to reduce stress will be of huge benefit in preserving a healthy immunity.
GET YOUR VITAMIN D
It’s well known to be vital to bone health and calcium regulation, but vitamin D also plays an important role in immune health. Our bodies mostly make vitamin D from exposure to sunlight as there are few edible sources available. However, the lack of natural light in winter leads many GPs to prescribe supplements. Consult your doctor if you think this is something you need.
GET YOUR SLEEP
Persistent sleep disruption significantly lowers your immune system, increasing inflammation and the risk of developing serious diseases such as heart disease or Type 2 diabetes.
A good seven to nine hours’ sleep a night could be considered one of your most potent weapons in improving your immune system.
White beans, butternut squash & spicy couscous
The problem with working in clinical medicine is that no day is the same and you rarely finish on time. Like the majority of people, NHS workers can also slip into the unhealthy habit of ordering a takeaway and turn to comfort food more regularly than we should.
This is one of those meals I made up from random bits in the fridge after coming back late from work. The beans and butternut squash are so satisfying in the spice mix, plus the couscous is incredibly easy to prepare. This is barely cooking. It’s simply prepping a few things and turning the oven on, which allows you to focus on winding down after a hard day.
- 200g butternut squash, peeled and cut into 2cm cubes
- 2 tbsp extra-virgin olive oil
- 2 tsp barbecue spice blend (see tip)
- 400g tin butter beans, drained and rinsed
- 150g couscous
- 50g sun-dried tomatoes (dry or in oil)
- 75g frozen peas
- ¼ tsp sweet paprika
- 200ml boiling water
The beans and butternut squash are so satisfying in the spice mix, plus the couscous is incredibly easy to prepare
Preheat the oven to 200c/180c fan/ gas 6. Scatter the squash on a baking tray and combine with the oil and barbecue spice blend. Bake for 15 minutes, then add the butter beans and bake for a further 10-15 minutes until the squash cubes soften and cook through.
While the beans and squash are baking, mix the couscous, tomatoes, peas and paprika in a medium heatproof bowl and pour over the boiling water.
Cover with a plate or large dish and set aside for 5 minutes. Once all the water has been absorbed, fluff up the grains with a fork. Serve the meal in bowls with the beans and squash spooned on top of the couscous.
DOCTOR’S ORDERS: Make your own barbecue spice blends – combine equal quantities of cayenne pepper, onion powder, ground cumin, crushed coriander seeds, mustard powder, dried oregano and a good pinch of salt and pepper.