Eating for Improved Immunity
The world is currently in unchartered waters, as countries face the Coronavirus pandemic known as Covid-19. Hand shaking is out and hand washing is very much in, as we try to keep ourselves healthy and unaffected by the global spread of this new virus.
It is therefore paramount at this time to ensure that our immune system is as healthy as possible in order to try and avoid becoming infected in the first place or, if we are infected, to ensure that our immune system is strong and can fight this virus effectively. This is especially important if you are considered to be in the high risk group of people that are classified as most vulnerable to Coronavirus including the elderly, those with cardiovascular problems and respiratory disease, diabetics and those who have cancer.
Our immune systems can also be weakened or compromised through things such as stress, tiredness, or poor diet, which can leave us more exposed and vulnerable to picking up illnesses. So what can we do to help strengthen our immune system naturally and how can diet and nutrition help improve our defences against illness to ensure that our immunity is at an optimum to do battle if needed?
Diet and Immunity
What we eat has a huge impact on how well our body functions and the link between immunity and nutrition has long been known. If we don’t provide our body with good nutritious foods, how can we expect it to work at an optimum level, maintain our health and fight off disease and infection? There are certain foods, vitamins and minerals that have been shown to have a positive impact on our immune system and it’s these foods we need to incorporate into our daily diet in order to stay healthy, especially during this unprecedented time. Even slight deficiencies in certain vitamins and minerals such as zinc and Vitamin C have been shown to impair immune function and leave us more susceptible to infection from a wide variety of illnesses. There are also foods which have been shown to reduce immune function and interfere with the body’s immune response, so at this present time when boosting immunity should be a primary focus, it’s these foods which we should be excluding or at least cutting down on.
Healthy Digestive system = A healthier immune system
70-80% of your immune function is found in the digestive system, so keeping your gut healthy is essential if you want a strong immune system. The gut flora (also known as microbiota) is the name for all the microorganisms that live in the digestive tracts of humans and that play a huge role in immune defence. Keeping this gut flora healthy is a strategic way of boosting our immunity. Fruits, vegetables and pulses are some of the best foods you can eat to keep your gut flora healthy. This is because they are all especially high in fibre and fibre is a critical component for gut health because it promotes the growth and flourishment of gut bacteria, in particular Bifidobacteria. Bifidobacteria is a group of bacteria called probiotics which are essential in helping protect the body from harmful bacteria that can cause illness and disease. Reduced amounts of Bifidobacteria in the stomach and intestines has been linked to many diseases and a reduction in immune function, so ensuring high levels of this by eating a range of fruit, vegetables and high fibre foods is vital to help boost immunity.
The word ‘fermented’ does not make this group of foods sound very appetising or appealing. However they are not like they sound and play a key role in helping strengthen immunity by keeping our gut flora healthy. Fermented foods such as yogurt, Sauerkraut, kefir, kimchi, sourdough and tempeh are all examples of fermented foods that have undergone a process of fermentation that results in these foods being a rich source of probiotics, which help to enhance and restore the health of the gut flora. One specific probiotic called Lactobacilli is found in most of these fermented foods and makes up part of your gut flora. Studies have shown that certain Lactobacilli strains help improve the body’s resistance to infection and also exhibit a certain anti-viral effect, so it plays a huge role in improving immunity. Studies have also shown that people that eat yogurt appear to have more Lactobacilli in their intestines than non-yogurt eaters, so if yogurt isn’t currently part of your daily diet it is definitely something to add.
This is a soluble fibre found in a variety of foods, including barley, oats, rye, shitake mushrooms, seaweed and yeasts (oats are the highest source). Some research has shown that Beta-Glucan can help strengthen the immune system, has antimicrobial and antioxidant properties and can enhance the function of some white blood cells needed to fight infections. It therefore goes without saying that foods high in beta glu-can should form part of your daily diet.
All vitamins and minerals play a part in a healthy immune system, however Vitamin D is particularly important as we can’t get what we need from food alone. In fact only a small proportion of our Vitamin D requirements come from food and approximately 90% of our requirements come from sunlight, something which we severely lack in this country. This is one reason why so many UK people are low or deficient in this crucial vitamin. Studies show Vitamin D has a big role to play in the activity and healthy functioning of white blood cells, with low Vitamin D levels shown to increase the risk of colds and flu. A large study in 2017 showed that taking Vitamin D supplements reduces the odds of developing a respiratory infection, and as Coronavirus specifically affects the respiratory system, anything you can do to strengthen and support this area is key.
In 2016, Public Health England (PHE) published new guidelines on Vitamin D, which came as a direct result of the increased incidence of low Vitamin D levels in the English population. The guidelines now state that adults and children over the age of one should have 10 micrograms (mcg) of Vitamin D EVERY day. This means that some people may want, or indeed need, to consider taking a daily supplement. The foods that you can obtain Vitamin D from include eggs, fortified foods and some mushrooms.
Selenium is a mineral essential for improving immunity and its deficiency, amongst other things, can cause immune impairment. Dietary intake of Selenium in many countries (including the UK) has been found to be lower than government recommendations, so it’s important that foods naturally high in selenium are eaten regularly. Good food sources of Selenium include Brazil nuts, sunflower seeds, brown rice and eggs.
Foods which negatively affect immunity
Some foods are known to have a negative impact on immune function and if consumed regularly or in large amounts, can leave you more susceptible to illness. Alcohol is one such item that not only reduces the body’s ability to absorb vital nutrients required for strong immunity, but it also interferes with the function and production of white blood cells which are vital to fight infection. Research has shown that alcohol can impair the function of macrophages (a type of white blood cell that acts as a first line of de-fence against invasion), as well as causing a reduction in lymphoctyes (another type of white blood cell vital for healthy immune function).
Consuming too much sugar and sugary foods may also weaken immunity by inhibiting a process called phagocytosis. This is the process by which some white blood cells engulf bacteria and viruses and thus keep us healthy, so if this process is inhibited our immune defences are weakened. Despite many people relying on foods and drinks containing caffeine to get them through the working day, its effects on the immune system are not that positive if consumed in large amounts. Excess caffeine raises cortisol levels in the body. This is the body’s stress hormone and raised cortisol levels may reduce immune function and leave you more susceptible to disease.
Other Immune Boosting Tips
There are different types of white blood cells in our body, all of which work slightly differently in helping to protect the body against infection and illness. These white blood cells circulate the body in our circulatory system, seeking out pathogens and fighting to protect you against disease and infection. However white blood cells are generally very sedentary creatures and if they are slow moving and don’t circulate effectively, their ability to protect us can be limited. It is therefore important to exercise and keep mobile to ensure constant and increased blood flow, which keeps those white blood cells circulating and active throughout our entire bodies in a timely manner, in order to be in the right place at the right time should a pathogen invade. So even if your mobility is restricted or you are self-isolating at home, make sure you keep moving. Even gentle movement and walking up the stairs or changing rooms keeps our blood flowing and our white blood cells more active.
If you are currently sleep starved, try your best to get more sleep and better quality sleep if at all possible, as we know lack of sleep negatively impacts immunity. If you are one of the thousands of people suffering from insomnia, then this can be a difficult task, but finding and trying different methods which may help induce sleep can be beneficial, of which there are reams of information on the internet and plenty of meditation and relaxation techniques to choose from and try.
If your stress levels are high and/or you suffer with anxiety, try and actively find ways to manage this and reduce it. This is key because prolonged and chronic stress and constant anxiety causes the stress hormones, mainly cortisol and adrenaline, to be constantly raised and circulating throughout the body. This physically affects your long term health and puts you constantly in a ‘fight or flight’ state, which amongst other things will leave you feeling constantly fatigued and ‘on edge’ and impairs immune function. Using even basic stress management techniques or meditative /mindfulness practices have been shown to help reduce stress and anxiety levels, so definitely worth a go to ensure your immune system is firing on all cylinders.
Strengthening immunity requires a multifaceted approach and in this time of uncertainty when we are trying to keep ourselves and loved ones healthy, making even small changes to diet and lifestyle can still have a big impact on boosting immune function.
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