In the midst of the COVID-19 pandemic, we know that there are certain things we can do to prevent contracting the virus, for example social distancing, wearing our mask and washing our hands frequently. But keeping our immune system strong and robust is also a crucial element to ensuring that we stay healthy during this time.
The role of the immune system is to protect us against pathogenic organisms such as bacteria, viruses, fungi and parasites. Defence against these pathogens requires a well-functioning immune system. As you can see in Figure 1 below, there are many factors that can influence the health of our immune system, including unmodifiable factors (e.g. genetics and age) and modifiable factors (e.g. nutrition, gut health, stress).
Nutrition is one factor that helps to determine the immune response. Poor nutrition may not provide the immune system with the adequate nutrients it needs to function properly, leading to poor defence against pathogens and increased susceptibility to infection. That’s why a balanced, healthy diet is an important aspect of a strong immune system, which helps to reduce the risk of contracting viruses (including COVID-19) and helps to protect us if we do contract them with usually milder symptoms and a faster recovery time.
We’ve listed below some important nutrients and vitamins that play key roles in supporting the immune system:
VITAMIN D: important for moderating the immune system and the best part is, you can get this vitamin for free from daily sunshine! Cod liver oil is another great source of vitamin D, and also contains vitamin A, which is an excellent antioxidant immune-boosting vitamin. Recent studies have reported an association between low vitamin D levels and increased risk and severity of COVID-19. See our previous interesting post: Can Mushrooms Create Vitamin D from Sunlight?
VITAMIN A: great sources of vitamin A come from apricots, carrots, green leafy vegetables and egg yolks.
VITAMIN C: a good water soluble vitamin that helps the immune system function effectively and protects against oxidative and inflammatory stress. Citrus fruits are famous for their high vitamin C content, but there are actually lots more foods that are bursting with this vitamin, including broccoli, raw cabbage, pineapple, strawberries and even parsley.
PROBIOTICS: our gut is our first line of defence with our immune system. It is lined with different types of immune and defence cells that will pick up different viruses and bacteria that come through the gut. Having a healthy gut requires having healthy microbiome (read our previous post on tips for restoring & strengthening your gut microbiome). Probiotics support both the immune system and the gut so that they can both do their job effectively.
ZINC: zinc is a powerful worker bee in the body. It’s important for so many different functions in the immune system, activates over 200 different enzymes in the body and helps to control oxidative stress and inflammation. Food sources of zinc include beef, beans, cashews, egg yolks, sunflower seeds, pumpkin seeds, oysters and nutritional yeast. Recent studies have reported an association between low zinc status and increased risk and severity of COVID-19.
IRON: iron transports oxygen around the body to all of our cells. Without oxygen our cells cannot function effectively, so making sure that we have proper iron stores is important.
HERBS: for example, anti-viral herbs (which help to stop viruses in their track and improve response to infection – elderberry is a good example - helps to mitigate inflammation, swelling, soreness and mucus production). Anti-bacterial herbs (e.g. garlic, oregano, thyme, green tea). Adaptogens (herbs that help our body adapt to stress) and immune stimulants (e.g. Echinacea).
Other lifestyle factors to consider:
STRESS: Stress dampens and weakens our immune system, affects our mood and our mental health. Find ways that work for you to alleviate stress. Get good sleep to allow your body to heal and regenerate (7-9 hours per night), laughter, connection, do things that you love (this helps our adrenals which strengthens our immune system).
EXERCISE: Daily exercise helps our cardiovascular system and our lymphatic system (which is also part of our immune system). When we move our body our skeletal muscles help to pump lymphatic fluid, which helps to flush out viruses and bacteria from our system. Exercise is also amazing for our mood, endorphins and our mental health!
Some of our previous posts on the immune system that you may find interesting:
European Journal of Clinical Nutrition, 2021