It is important to understand how both nutrition and lifestyle habits can impact our immune system as we go into winter season and continue to face the covid-19 pandemic.
So what can we do to stay healthy during the covid-19 outbreak?
A) Lifestyle habits that support immunity
B) Dietary components that support immunity
People often get too carried away focusing on certain food groups and cutting out others due to the vast amount of misinformation found circulating in the weight loss community particularly. Our eating pattern is way more important than just focusing on one food or nutrient.
It’s important to follow a healthy balanced diet that contains a good variety of foods because one food does not contain all the nutrients that we need to stay healthy. To ensure that you are getting a good variety of foods, we use the balanced plate model as seen above. This model demonstrates that half of your plate should be vegetables and fruit, a quarter should be lean protein rich foods and the last quarter should include fibre rich carbohydrates like whole grains or starchy vegetables. By balancing your plate with these different foods, it will ensure that you get all the nutrients that you need to support your immune system.
Our immune cells are made of out protein, therefore sufficient protein is crucial for keeping our immune system strong. A strong focus should be put on pant-based proteins (legumes, beans, soya), as these proteins don’t contain the unhealthy fats that are found in animal proteins, and bring a wide variety of nutrients and fibre to the plate. Too much fat from animal proteins increases inflammation in the body, causing a detrimental effect on our immune system. More of a focus should be put on fats that come from plants (nuts, seeds, oils, avos, olives) and fatty fish (salmon, mackerel, snoek, fresh tuna, pilchards, sardines, herring). The omega 3 fats from fatty fish regulate inflammation in the body and are also important for mental health, which is crucial during a pandemic where it can be easy to feel isolated and alone.
Carbohydrates are an excellent source of energy while also providing a good range of nutrients when in the non-processed state. Following a very restrictive diet and cutting out carbs can result in inadequate energy and nutrient intake (veg are also carbohydrates!), which will have negative effects on the immune system too. So don’t fear carbs! There is no reason to cut them out of your diet!
Added sugars and ultra-processed junk foods should be limited. This doesn’t mean that you should cut it out completely, but rather enjoy these treat type of foods occasionally! Ultra-processed foods are often loaded with excess salt, fat and added sugar, which has detrimental effects on our health and immune system.
We all know that we should be eating vegetables every day but what is very important is that we eat the rainbow. This means incorporating different types and coloured veg into our diet weekly, since the different coloured veg provide different phytonutrients that support our immune system and help reduce inflammation in the body.
About 70-80% of our immune cells live in our gut. Therefore, gut health is also important for keeping our immune system healthy. Getting sufficient fibre from a variety of plant-based foods like fruits, veg, nuts, seeds, wholegrains is best for feeding the good gut bacteria in our gut!
C) Specific vitamins & minerals that are immuno-supportive
During times of stress and infection, blood levels of vitamin C are reduced. Vitamin C is essential in the diet as it has to been sown to reduce symptoms, shorten the duration and severity of respiratory tract infections and the common cold. Vitamin C can be found in citrus fruits, bell peppers, cauliflower, broccoli, berries, dark green leafy veg, mango, pineapple, kiwis.
Vitamin D has multiple functions in the body. It has been shown to reduce the risk for respiratory infections and the severity of covid symptoms! For this reason, it is important to get enough vitamin D from the sun and your diet. The recommendation is to spend 10-15 minutes in the sunlight with your arms, hands, legs and face exposed 2-3x per week and to incorporate foods like fatty fish, tanned mushrooms, egg yolk, dairy products and fortified non-dairy products such as orange juice and breakfast cereals into your diet.
Zinc is essential for immune cells to form and function optimally. A zinc deficiency can impair wound healing and increase the risk of pneumonia and loss of smell and taste. We don’t have good storage of zinc in the body so it is important to eat zinc sources often enough. Zinc rich foods include seafood (lobster, crab, oysters), chickpeas, baked beans, cashews and pumpkin seeds.
Selenium is important for immune cell regulation and a deficiency in selenium has been shown to increase the risk of infection. Again, it's important to ensure that you get enough from your diet by incorporating selenium rich foods like brazil nuts (3-5 nuts per day), seafood, whole grains, meat, chicken and eggs into your diet.
Magnesium helps with the building of immune cells. It also promotes sleep and reduces anxiety and stress, which could all impair the immune system if not optimal. Magnesium is therefore key for a healthy immune system. You can find magnesium in wholegrains (barley, bulgar, oats, quinoa, wheat germ), molasses, dark chocolate, almonds, pumpkin seeds, cashews, walnuts, legumes, green leafy veg and potatoes. Excess alcohol intake increases the kidney’s excretion of magnesium into the urine, which is another reason why alcohol intake should be regulated.
D) Herbal remedies
Ginger might be helpful for immunity since it has potent anti-inflammatory and antioxidant phytochemicals. Consider adding it to tea or juice. Turmeric is a root that looks very similar to ginger. You can buy it fresh or dry and use it during cooking or in juices or smoothies. Curcumin is the active ingredient in turmeric and it has anti-inflammatory and antioxidant properties. The bioavailability is however low (meaning that the body struggles to use it) and it is broken down in the body very quickly. Combining turmeric with black pepper can reduce the rapid degradation of turmeric and boost its bioavailability. Probiotics and prebiotics are also now widely available. They can be taken as supplements or in the form of fermented foods and drinks. The two together promote a healthy gut by promoting the growth of the beneficial bacteria in the gut. A healthy gut means a healthy immune system and so both can play a role in supporting the immune system.
To conclude: Eating a well-balanced diet and including immune supportive foods is essential for keeping our immune system strong and maintaining optimal overall health and wellbeing. Try incorporating the immune supportive foods into your favourite recipes to help increase your intake of them. Supplements can be part of a healthy diet for supporting immunity but it is always important to use a food first approach where you aim to get a sufficient amount of vitamins and minerals from food first and then only supplement if you still struggle to meet your requirements. If you feel like you are not meeting your requirements for any of these nutrients, it is important to consult with a dietitian and your GP before supplementing on your own, since exceeding the recommended intake amount can be harmful and drug interactions or contraindications have to be investigated first.