The importance of nutrition and a healthy immune system 3

We can finally wave goodbye to promises of an Indian summer, the nights are drawing in, the temperature is dropping and for some, the sniffles and coughs have started. It’s no coincidence that health complaints start when the new term at school begins, with schools, nurseries and the workplace all perfect incubators for bacteria. Before you fear the impending days off work to look after yourself/the kids, let’s look at the some of the many ways  your immune system works, the nutrients required to keep the immune system working optimally, and the practices you can put into play today to ensure defences are high and primed to prevent the fever, cough and blocked nose from affecting your productivity and plans for the coming months.

The secret to good health: your immune defenders

Want to know the secret to good health? It’s called the immune system, an intelligent and complex web of cells, bacteria, barriers and secretions, working to protect the body from foreign and potentially harmful substances, working on three different levels.

  1. Skin and outer mucous layers form physical immune barriers

The tonsils play a key role in immune function

Skin is an outer barrier to potentially harmful substances, providing protection to vital organs and exposed surfaces. The acid that sits in your stomach not only works to break down protein from food into amino acids, but, with its low pH, also works to destroy any potentially harmful substances from travelling beyond the stomach where they can wreak havoc. These, along with many other cells and structures, form part of the immune system that provide a barrier to entry – consider them the large brick wall, and deep river that protects everything on the inside. The tonsils and appendix are other important features of the immune barrier; think of them as the gatekeepers of the immune system, checkpoints where infections are fought off. The microbiota, a series of bacteria living in and around the body, also form part of the barrier, with more and more emerging data revealing the vast and multifaceted role the microbiota (with 10x more microbes than the body has cells) play in our overall health.

  1. The innate immune system is largely inherited from your mother

Then we have the innate immune system which is inherited from your mother at birth, consisting of cells that can be found in blood and tissue. These are cells that live in lymphatic tissue. Consider the cells that make up the innate immune system the babysitters, not necessarily trained to deal directly with an intruder, but able to alert the appropriate authorities should a threat be detected. Inflammation is key in the innate immune system, with cells of the innate system triggering inflammation in order to sound the alarm to the area required. This allows a threat to be restricted to one area, with specific inflammatory actions occurring, such as a lot of blood coming to the area, with increased clotting to allow healing to occur, leading to heat in the area, redness of the area, pain in the area, possible swelling in the area, and loss of use. Whilst these are not particularly pleasant side effects of inflammation, these important signs can often lead to us noticing a problem, e.g. swollen tonsils, pain to alert you to a problem, loss of use of a broken ankle, for example, to stop you from running on it and causing further damage.

  1. The adaptive immune system is honed from exposure to bacteria and viruses

Finally, we have the adaptive immune system, which we develop during a lifetime of exposure to foreign bodies, forming ‘memories’ about the level of danger a substance may hold, and how to deal with it appropriately. Adaptive immune cells mainly consist of T and B cells, and are found in lymphatic tissue. These are the security firm to your home, and the effectiveness of them relies on how much you support them with good quality lifestyle and nutritional practices, allowing them to work more efficiently. Your security guards need lots of energy and nutrient-dense food to keep them in peak physical condition, as well as a good ‘perks’ package consisting of sleep, rest and holidays.

Now you have a brief understanding of all the different ways the immune system works, let’s discuss how you can support it so it can better support you and leave you feeling fighting fit for the winter months and beyond.

Feeding the immune system for maximum protection

A diet rich in colour will provide lots of essential vitamins, minerals and antioxidants

The immune system loves nutrients; from vitamins and minerals, to probiotics and pre-biotics; never has it been more fitting to stress the importance of a well-balanced diet when it comes to immune support. Natural, non-processed foods such as fruits, vegetables, nuts, seeds, beans, pulses and organic animal produce provide the most nutrient dense foods. Let’s look at the key nutrients, their importance to immune health, and the richest food sources of each of them.

Vitamin A is essential for supporting the health of the gut lining, the first line of defence preventing harmful substances from passing the stomach lining and entering into the body’s circulatory system where problems may start to occur. Foods rich in vitamin A include brightly-coloured fruits and vegetables such as sweet potato, carrots, dark green leafy vegetables, cantaloupe, peppers and tomatoes.

Tip: eat the rainbow – the brighter your plate, the more vitamin A it will contain

Vitamin C has been shown to support a quicker recovery from symptoms of the common cold; however, levels are often depleted by infections, as well as in times of stress. This may explain why you often feel run-down when ‘burning the candle at both ends’.  Vitamin C is only derived from plant foods, with citrus fruits being one of the most popular forms; other sources include brightly-coloured fruits and vegetables, especially papaya, peppers, cruciferous vegetables, berries, pineapple, kiwi and grapefruit.

Pineapple and papaya not only provide the full recommended daily intake of vitamin C per serving, but they are also considered immune saviours for their anti-inflammatory and antioxidant benefits. They also support the breakdown of proteins, required by cells of the immune system when fighting against invaders which need to be broken down. To benefit from the protein breakdown benefits of pineapple, you need to eat the core and stem – perfect for your juicer rather than a fruit salad!

Vitamin D is important for both the innate and the adaptive immune system, with deficiency linked to an increased susceptibility to infection. As skin exposure to the sun is the main source of vitamin D, it is no surprise that immune health is often compromised during the cooler months when there is less sun exposure, and the skin is covered against the cold temperatures. Unlike vitamin C, most food sources are animal based, except for mushrooms, and include salmon, sardines, milk, tuna and eggs. Whilst some processed foods are fortified with vitamin D, it is very difficult to rely on the diet alone to maintain optimal vitamin D levels year-round; a vegan would require 50 cups of mushrooms, a vegetarian 3 glasses of milk or 10 eggs, and an omnivore/pescatarian 1 portion of fish or 2.5 tins of sardines per day.

Supplements: If you suspect your vitamin D levels are sub-optimal, you can top-up your vitamin D intake with Pure Essentials Daily Vitamin D3 (or Pure Essentials Vegan Vitamin D3 for those following a plant-based diet) to efficiently increase blood levels and support immune health year-round.

Just two oysters are needed to provide your full recommended daily intake of zinc

Zinc, like vitamin D, is also important for both the innate and the adaptive immune system, with deficiency negatively affecting the ability of the cells of the immune system to develop and function. Oysters are the richest source of zinc, with just two providing a full daily intake of zinc. Other sources include grass-fed beef, lamb, sesame and pumpkin seeds, chickpeas, lentils, cashews, spinach, asparagus and mushrooms.

Selenium is an important antioxidant in the immune system, supporting the productions of the body’s own inbuilt antioxidants to provide protection from the damaging effects of free radicals which, amongst many other sources, can result from an immune reaction. Food sources include Brazil nuts, fish and shellfish, poultry, tofu, eggs and mushrooms. In fact, Brazil nuts can provide as much as 10x the recommended daily intake of selenium, depending on the source, making a wonderful addition to a trail mix or try a brazil nut and rocket pesto.

Iron is also required to support the body’s production of inbuilt antioxidants. Whilst many believe that red meats are the main source of iron, you can also obtain this essential mineral from lentils, chickpeas, beans, sesame seeds and dark green leafy vegetables.

These black bean brownies are a sure fire way to increase children’s intake of pulses

Tip: You don’t need to be vegan to benefit from nutrient-dense chickpeas, lentils and beans; try hummus and crudités as a healthy snack, add lentils to soups and stews, and if you’re feeling adventurous, how about this black bean brownie recipe?

For everyday immune support, and to top-up food intake, Pure Essentials Advanced Multivitamin & Minerals contains vitamins A, D, C, selenium, zinc and iron in their most active forms to support immune health.

Probiotics enhance the beneficial effect of the microbiota. Whilst most people think of supplements when they think of probiotics, you can also obtain healthy bacteria from foods, with the most common food source being natural Greek yoghurt. If you like pickles, you’re in luck as pickled foods also contain live bacteria. If you’re feeling adventurous, you could also try kefir, kombucha and tempeh, which are great sources of friendly bacteria. If you are interested in making your own cost-effective probiotic, try this sauerkraut recipe which can be added to salads or used as a garnish with a meal when ready.

Prebiotics are the food for your microbiota, required to keep your body’s good bacteria

thriving. Food sources include raw Jerusalem artichoke (quite similar to a radish in flavour), garlic, onion, leek and asparagus. Garlic and onion can easily be added to your daily diet – used in stocks for soups, curries and casseroles.

Astaxanthin is the king of antioxidants

Antioxidants, as previously mentioned, provide a source of protection to cells from the damaging effects of free radical damage occurring as a result of immune activation, environmental exposure to toxins, poor diet, lifestyle factors, stress and so on, with suboptimal levels linked to reduced immunity. Whilst many vitamins and minerals also provide antioxidant protection, the top-scoring antioxidant is astaxanthin which is derived from algae and responsible for the pink-red colouring of seafood such as salmon, crab and lobster. Other high ranking antioxidants include herbs and spices (oregano, rosemary, peppermint, thyme, cinnamon, turmeric and sage). Cooking from scratch, using herbs and spices for flavour, is a simple way to increase your antioxidant intake.

Want a convenient way to ensure your antioxidant defences are high? Pure Essentials Astaxanthin provides a handy way of topping up your antioxidant intake, with 1 capsule providing 5x as much astaxanthin as 1 portion of farmed salmon. For intensive support, we recommend Longvida Optimised Curcumin. Curcumin is well known for its antiviral, antibacterial, anti-inflammatory and antioxidant properties, perfect for providing intensive immune support.

Omega-3 oils support a healthy inflammatory reaction as a response to immune activation, therefore essential for ensuring proper immune function. Apart from our ultra-pure fish oils, omega-3 can be consumed from eating oily fish (mackerel, anchovies, salmon, herring and sardines), flaxseeds, walnuts and soya beans. Whilst oily fish and fish oils provide higher concentrations of the long-chain omega-3 fatty acids EPA and DHA, plant sources of omega-3 only provide shorter chain fatty acids and must be converted by the body to EPA and DHA, a process the body is not very efficient in dealing with.

For intensive support, we recommend Pharmepa MAINTAIN, a super strength wild fish oil supplement containing higher levels of EPA & DHA per serving, with an optimal ratio of omega-3 to omega-6 to support inflammatory balance.

Listening to your body and supporting it naturally

When optimising immune defences, it is essential to listen to your body. This is not always an easy task but if you find that your energy levels have dipped more than usual, rather than push on regardless, take that as a sign that your body needs to rest; your immune system may have been working hard to protect you from the increased onslaught of viral and bacterial threats and may need the additional time to recuperate. Sleep is essential for recuperation so use your weekend as an opportunity for a Sunday lie-in (child-dependent, of course), and allow yourself to go to bed early mid-week, leaving a few of your tasks for the following day.

When feeling run down, ensure lots of rest so as not to overburden the body

If you’re feeling run down, try a warm and relaxing bath to increase body temperature and to calm the body

Now is not the time to be taking on large projects or hitting the gym every day. Whilst mental and physical exertion is wonderful for your health under normal circumstances, the added stress involved may overburden a system that is already weighed down. Instead, consider a mental vacation with some meditation, a relaxing bath or an early night with a book in bed; instead of hitting the gym, go for a gentle walk outdoors in nature, or consider a calming exercise such as yoga or tai-chi. If your gym has a sauna, make full use of it, as the body becomes more efficient at fighting infection when the body temperature is warmer, one of the reasons many Scandinavian homes come complete with an inbuilt sauna.

Keep hydrated to flush out toxins

Hydration is key for optimal immune function, encouraging the immune cells in the blood to be pumped around the body where they can protect against invasion. Water also helps the kidneys to flush out toxins. Why not add a slice of lemon or lime to your water to provide a double immune-boosting benefit of increasing your vitamin C intake?

Diet is key – here are some immune saving recipes

If you are feeling run-down, take the opportunity to feed your body with more energy-dense foods, as listed above, to ensure you are getting all of the nutrients required to support a healthy immune reaction. Be aware of your sugar intake too, as added sugar impedes the body’s ability to absorb vitamin C and subsequently suppresses immune activity. Preparing a large vat of lentil and vegetable soup, with lots of added herbs and spices, served with side of pickled beetroot or sauerkraut is a great way to consume many essential immune-fighting nutrients. A fruit salad served with natural Greek yoghurt, a few Brazil nuts and a sprinkling of seeds makes for a wonderful immune-boosting breakfast or a healthy alternative to your sweet mid-afternoon snack. Don’t forget a couple of portions of oily fish per week to support vitamin D and omega-3 intake.

Boost immune function – manually

To give your immune system an extra boost, you could also consider dry body-brushing which encourages blood circulation and lymph flow. All you need is a dry body brush which can be purchased from spas or health shops, and ten minutes to brush, before a shower, bath or even before a sauna, to complete the process. Here is your step-by-step guide. Manual lymphatic drainage, a massage which increases lymph flow and supports the drainage of toxins, is another way to boost immune function.

Whilst solid dietary and lifestyle factors can provide a great boost to immune health, the complex nature of this multifaceted system means there can be many other factors negatively impacting on immune health; poor digestion of nutrients, increased exposure to toxins, allergies, food sensitivities, stress, and so on. If you would like more support from our nutritionists, do feel free to contact us via live chat, call us on 01223 421436, or email

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Maxine Sheils

About Maxine Sheils

Maxine is a Nutritional Therapy graduate of the College of Naturopathic Medicine in Manchester who has recently joined Igennus as a customer support nutritionist and is based here in Cambridge. Her interest in nutrition was sparked after working as an au pair in Australia to a family who were living on a raw food diet where coincidentally, she started to endure severe digestive problems. She joined CNM as a student to further her new found passion and was able to support her own body in regaining health. Maxine is passionate about nutrition and her ability to help others achieve their optimal health. She specializes in female hormonal problems such as endometriosis, thyroid problems, stress, autoimmunity and digestive disorders. Her degree in psychology provides her with a strong ability to understand and motivate others to achieve their health goals.

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3 thoughts on “The importance of nutrition and a healthy immune system

  • Laura May Ephraim-Jones

    Amazing educational yet interesting article. Thank you so much for intiroducing this to me! It all makes sense now I have been craving salmon and veg since being ill like my body needs it. Thank you so much.

  • Jhoei

    A healthy immune system will definitely protect our body from being sick and infected with bacteria and viruses. So we must choose the right kinds of food that will boost our immune system.