While we wait for a coronavirus vaccine to be developed, tested and released, our best protection against COVID-19 is physical distancing, stringent hygiene practices and keeping our immunity in top shape. Healthy Food Guide editor Jenny de Montalk looks at the three main ways you can support your immune system through lifestyle.
1 Eating for a healthy immune system
The immune system is our body’s defence against infection. It fights pathogens that enter our body, learns to recognise bad bacteria and viruses it has encountered before and ‘remembers’ how to best fight them.
That’s why it’s important to keep your immune system in top shape, to give it the best chance of keeping you well.
The immune system consists of multiple barriers to infection including the skin, mucous layers and blood cells and tissues.
Much of the immune system resides in the gut, and the gut microbiome (bacteria, fungi and yeast) is integral to how that functions. So, eating a range of foods that help feed your gut microbiome is at the heart of supporting your immune system.
Fibre-rich foods, such as vegetables, fruit, legumes, nuts and whole grains are the optimal food for your gut bacteria, and making them a main feature of your diet is the best place to start.
Fermented foods, such as yoghurt, cheese, sauerkraut, kimchi and kombucha, contain beneficial bacteria and yeasts, and including them daily can help boost your gut flora.
Limiting alcohol and reducing your intake of saturated fats may also keep your gut bacteria profile in the healthy range.
Limiting additives, such as emulsifiers, and eating omega-3 containing oily fish will provide additional anti-inflammatory and floral diversity benefits.
As well as keeping your gut microbiome in top shape, it’s important to eat a range of foods that are rich in immune-supporting vitamins and minerals.
Vitamin C helps white blood cell and antibody production, so eat plenty of vegetables and fruit well before you get sick, to hit your daily target.
Eggs are a great source of vitamin A which has a crucial role in maintaining immune function.
Iron also helps the immune system work at its best, so making sure you aren’t deficient is key.
Eating iron-rich lean red meat, in small portions, a couple of times a week is the easiest way to keep your levels right. If you don’t eat meat, legumes, tofu, eggs, cereals and green leafy vegetables will be your main sources. Try to eat them with vitamin C-rich foods, to increase absorption.
Oats and other whole grains are a good source of B vitamins which may help the body fight off infection and help with recovery.
Finally, zinc helps your white blood cells work at their best to fight infection. Excellent sources are oysters, mussels, prawns, squid and salmon. If you don’t eat fish, many nuts, such as almonds and walnuts, provide zinc.
2 Exercise and immunity
Regular exercise has many benefits for both our mental and physical health. By improving your circulation, exercise may help infection-fighting cells and molecules move more easily throughout the body.
It also improves cardiovascular health, lowers blood pressure and helps us maintain a healthy weight. And exercise is an effective way to help manage type 2 diabetes.
This is particularly important when it comes to COVID-19 because these are all factors in how severe infection with the disease may be.
Exercise taken outdoors has the added benefit of exposing your skin and eyes to sunlight, which helps your body produce vitamin D, another essential nutrient for immune-system function.
It is recommended we do at least two-and-a-half hours of moderate or one-and-a-quarter hours of vigorous exercise over the week, but for the most benefit we need to aim for at least five hours of moderate or two-and-a-half hours of vigorous exercise per week.
3 Stress and your immune system
Research into the relationship between stress and immune system function is ongoing, but there is evidence chronic stress is associated with decreases in almost all functional immune measures.
Given we are living through an unprecedented pandemic with huge social and economic ramifications, it’s hardly surprising many of us are feeling stressed out.
But managing your stress levels may be the final piece in the puzzle of keeping your immune system fighting fit.
Managing stress effectively isn’t about eliminating it altogether. Stress can be a helpful motivator. It helps us make sure we study for an exam and motivates us to make and achieve our goals.
But being over-stressed can be crippling, making us turn to unhealthy habits such as overeating or drinking too much alcohol which, in turn, may suppress immune function.
The trick is to work out what puts you into an over-stressed state (this is different for different people) then apply actions that help you unwind.
This might be going for a run, listening to your favourite music, chatting with a friend over the phone, yoga, breathing exercises or having a hot bath – whatever works for you.
Treat yourself kindly when you feel under pressure and have a toolkit of actions you know relieve the pressure for you, so you can turn to them, rather than more unhealthy coping mechanisms.
Article sources and references
- Zhiyi Huang,Yu Liu,et al. Role of Vitamin A in the Immune System. Journal of Clinical Medicine 2018 September. doi: 10.3390/jcm7090258https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6162863/
- Cynthia Aranow, MD, Investigator. Vitamin D and the Immune System. J Investig Med. 2011 Aug; 59(6): 881–886. doi: 10.231/JIM.0b013e31821b8755https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3166406/
- Helpful ways to strengthen your immune system and fight off disease. Harvard Healthhttps://www.health.harvard.edu/staying-healthy/how-to-boost-your-immune-system
- How much activity is recommended? Ministry of Healthhttps://www.health.govt.nz/your-health/healthy-living/food-activity-and-sleep/physical-activity/how-much-activity-recommended