By Natasha de Almeida
Nutrition and immune health has become a popular topic in 2020. Aside from Tiger King: Murder, Mayhem and Madness, another google search of interest was that of immunity and how one could stop themselves from contracting the virus. Terms such as ‘vitamin C’, ‘immune system boosters’, and ‘dietary supplements’ were searched on google up to 5000% more times in March 2020 than in previous months.1-3While this interest in nutrition and immune health is exciting to us, some information found on the internet may be rather misleading.
So, let’s try and clarify a few things!
Research has shown that a healthy, well-balanced diet can help strengthen the immune system. Does this mean that good nutrition can prevent you from contracting viruses like COVID-19? Not necessarily – viruses like these are incredibly infectious, meaning any one of us, well-nourished or malnourished, can contract it. But what it doesmean is that you can help prepare your immune system by maintaining a good nutritional status, thus potentially improving your outcomes should you contract an infection. And what better way to help strengthen the immune system than through food!
Certain nutrients have come under the limelight because of their abilities to improve immune health. These nutrients include: Vitamin C, Vitamin D, Vitamin A, Vitamin E, Zinc, Selenium, Omega-3 fatty aids and dietary fibre.
Vitamin C has been shown to be protective against infectious diseases, particularly respiratory ones such as pneumonia and tuberculosis. It acts as an antioxidant, which helps protects our cells from oxidative damage, as well as an anti-histamine, which can help improve flu-like symptoms.4,5
The vitamin that has created the most buzz in the scientific realm in recent months has been Vitamin D. It works as an anti-inflammatory and can reduce the severity of viral infections, particularly respiratory infections. Vitamin D is unique in that it can be synthesised by our skin when we are exposed to sunlight. 4,5,6 Fifteen to thirty minutes of sunshine everyday can do you wonders, just remember to protect your skin.
Vitamin A deficiency has been associated with an increased risk of infection. Vitamin A helps with the growth of our immune cells, protecting us from illness and infection.5
Vitamin E, like vitamin C, is an antioxidant and helps improve our bodies antibody response to infection.4,5
Zinc is a mineral that acts as an anti-viral and helps recruit immune cells in the body to help fight infection.4,5 It is important for wound healing and can even improve the symptoms of a common cold.
Selenium, also a mineral, help support the immune system as an antioxidant, which might provide protective effects against some types of cancer.7 Selenium deficiency has been associated with viral infections such as influenza.5
Omega-3 fatty acids
Omega-3 fatty acids are considered ‘healthy fats’ as they improve the healthy cholesterol levels in the blood. Omega-3 has both anti-inflammatory and antioxidant properties. 4,5
Fibre is often overlooked. We always say, ‘less fat’ or ‘less sugar’, but sometimes we forget to say MORE FIBRE. Fibre gets fermented by the good bacteria in our gut, and the products of this fermentation have anti-inflammatory actions that can help improve our immune health.5,8 So not only does fibre help regulate our bowel movements, it also improves our immune health!
|Nutrient||Benefit||Examples of Food Sources|
|Vitamin C||Antioxidant and antihistamine||Fruits and vegetables namely: Red and Green peppers Citrus fruits (oranges, grapefruit) Kiwi Tomato|
|Vitamin D||Anti-inflammatory||Fish Eggs Fortified milk Mushrooms|
|Vitamin A||Growth of immune cells and protection from illness and infection.||Carrots Spinach or kale Liver (beef and chicken) Eggs|
|Vitamin E||Antioxidant and improves immune response to infection||Nuts (almonds, hazelnuts, peanuts), Sunflower seeds Plant oils (sunflower, soya, corn, olive) Wheat germ found in cereal products Broccoli Blueberries|
|Zinc||Anti-viral and helps recruit immune cells to fight infection||Red meat and Poultry Oysters Dairy products Whole grains Beans Nuts|
|Selenium||Antioxidant||Nuts Whole grains Cereals Mushrooms Dairy products Poultry, Red meat and Seafood|
|Omega-3 fatty acids||Anti-inflammatory||Walnuts Flaxseed Canola oil Avocado Eggs Fish (salmon, sardine, tuna, mackerel)|
|Dietary Fibre||Fermentation of fibre in the gut provides products that help strengthen the immune system||Whole grains Fruits Vegetables Legumes|
Supplements: to buy or not to buy?
Our first choice of obtaining vitamins and minerals should be through food. A healthy and well-balanced diet will help you get the right nutrients that you need to help improve the functioning of your immune system. So no, you don’t have to sip on dissolved vitamin C effervescent tablets like they’re wine on a Friday night.
Vitamins and supplements are there for those who are deficient or are not meeting their nutritional demands. This could be for various reasons, such as disease, allergies, intolerances, or dietary preferences that cause you to avoid certain foods. Pregnant or lactating women, young children or the elderly may also need to use them. In these instances, the use of vitamins or supplements could be useful. If you are worried that you may need a nutritional supplement, you should discuss this with your doctor and dietitian first.9
The reasons for consulting your healthcare professional before choosing and purchasing supplements are five-fold9:
- Vitamins may not be necessary as you may be able to meet your needs through food alone. Food has benefits that supplements do not have and should always be the first option.
- Vitamins and supplements can be very expensive. Why put a dent in your budget if it is not necessary?
- Some supplements on the market are advertised as doing magical things to boost your immune system, without scientific evidence to back their claims. A dietitian will be able to do the necessary research to help you identify which supplements to get – that is, if you even need them.
- Taking vitamins in excess of what you need may be doing more harm than good.
- Some vitamins or supplements may interfere with certain medications and may be unsafe for you if you suffer from a medical condition.
In a nutshell, to help strengthen your immune system enjoy a variety of whole foods (those that are not processed, high in fat or sugar), drink clean and safe water, practice healthy eating habits and get some well-deserved SLEEP.
The theme for this year’s National Nutrition and Obesity week was Good Nutrition for Good Immunity. For more information about nutrition and immune health, please visit https://www.nutritionweek.co.za
Fighting a virus is your bodies equivalent of going to war. So, make sure it has the right weapons to use, like a well-functioning immune system.
- Google Trends. 2020. Google Trends. [online] Available at: <https://trends.google.com/trends/explore?date=2020-03-01%202020-03-31&geo=ZA&q=vitamin%20c> [Accessed 27 September 2020].
- Google Trends. 2020. Google Trends. [online] Available at: <https://trends.google.com/trends/explore?q=%2Fm%2F025sjz4&date=2020-03-01%202020-03-31&geo=ZA> [Accessed 27 September 2020].
- Google Trends. 2020. Google Trends. [online] Available at: <https://trends.google.com/trends/explore?q=%2Fm%2F0q593&date=2020-03-01%202020-03-31&geo=ZA> [Accessed 27 September 2020].
- Shakoor, H., Feehan, J., Al Dhaheri, A., Ali, H., Platat, C., Ismail, L., Apostolopoulos, V. and Stojanovska, L., 2020. Immune-boosting role of vitamins D, C, E, zinc, selenium and omega-3 fatty acids: Could they help against COVID-19?. Maturitas, 143, pp.1-9.
- Iddir, M., Brito, A., Dingeo, G., Fernandez Del Campo, S., Samouda, H., La Frano, M. and Bohn, T., 2020. Strengthening the Immune System and Reducing Inflammation and Oxidative Stress through Diet and Nutrition: Considerations during the COVID-19 Crisis. Nutrients, 12(6), p.1562.
- Wu, D., Lewis, E., Pae, M. and Meydani, S., 2019. Nutritional Modulation of Immune Function: Analysis of Evidence, Mechanisms, and Clinical Relevance. Frontiers in Immunology, 9.
- Mahan LK, Raymond JL. Food & the nutrition care process. 14th ed. Seattle, WA: Elsevier; 2017
- Valdes, A., Walter, J., Segal, E. and Spector, T., 2018. Role of the gut microbiota in nutrition and health. BMJ, p.k2179.
- Bda.uk.com. 2020. Supplements. [online] Available at: <https://www.bda.uk.com/resource/supplements.html> [Accessed 13 October 2020].