Wearing masks on public transport is compulsory from today, which is no doubt a good precaution against the spread of COVID as people return to work. But apart from the practical measures of washing hands and social distancing, we can fortify ourselves from within, by nourishing our precious immune system so it can keep us safe and healthy.
How does our immune system work?
Our immune system is hugely complex but it basically comprises two parts: the general innate system and the adaptive, specialised one. The former is our first line of defence, acting quickly when it detects a pathogen (germ) – e.g. bacteria entering the skin through a wound – and destroying it. However, because the innate system is not specialised at targeting specific pathogens, it may not be able to stop the spread of germs and you may become ill for a few days. During this time the adaptive system kicks in, taking note of the invaders and building antibodies so that next time the pathogen strikes, it will remember it and you will either experience very mild symptoms, or you will be immune.
In order for this process to work effectively, we need to give the immune system all the support it needs, starting with fruit & veg. Here are a few tips to help you take care of your ‘inner security guard’.
1. Double your 5-a-day!
Fruit and veg contain powerful nutrients, known as phytochemicals, that protect the plant while it’s growing and confer this protection to us when we eat them. They are a rich source of antioxidants that help neutralise the harmful molecules (known as free radicals) that are released by the pathogen. The more of these we eat, the better our immune system will function so go for it, eat the rainbow, in the knowledge that every colour gives you a different powerful benefit. And why stop at 5? If you have some berries for breakfast, a big salad at lunch time and a few leafy greens and broccoli for dinner – you’ll easily reach a much more beneficial 10-a-day!
Here's the lowdown on how nutrients from your fruit and veg can support your immune system:
Vitamin A - helps maintain integrity of digestive tract, lungs & cell membranes so helps prevent foreign agents entering.
Found in liver, spinach, watercress, carrots, butternut squash, red peppers, mango, melon and apricots.
Vitamin C – the ‘master’ immune supporting vitamin. Helps immune cells to mature and improves the performance of antibodies. It is anti-bacterial and anti-viral and destroys toxins produced by bacteria. It is also a natural anti-histamine, calming down inflammation.
Found in: red & green peppers, kiwifruit, strawberries, oranges, papayas, broccoli, tomatoes, kale, sugar snap peas, parsley, red chilli, rosehips.
As it's difficult to get adequate vitamin-C from these foods, supplementation is recommended. It's important to get the right dose: only studies that used over 1 gram daily were effective.
Vitamin E - improves immune cell function
Found in sunflower seeds, sesame, wheatgerm, salmon, sardines, sweet potatoes, almonds, beans, avocados, olives
Zinc - Critical for immune cell production and has antiviral properties
Found in meat (offal), shellfish, eggs, pumpkin seeds
Vitamin D – helps to activate the immune system to defend us against invading microorganisms
Main source: the sun. Also found in oily fish like salmon, mushrooms, egg yolks and some fortified breakfast cereals.
2. Look after your gut
Did you know that 70% of your immune cells reside in your gut? So it goes without saying that a healthy gut means a healthy immune system. Here’s what you can do to nourish your gut, aka the microbiome.
Ensure your diet is rich in fibre, especially soluble fibre found in vegetables, as this provides good fuel for the beneficial bacteria, helping to preserve the health of the gut lining.
To encourage a better balance of bacteria in the gut, eat fermented foods such as miso, sauerkraut, kombucha, kefir, yoghurt and sourdough.
Eat prebiotics – foods that nourish the bacteria – eg. leeks, garlic, onions and Jerusalem artichoke.
3. Spice up your life!
Season your food with turmeric, ginger, cinnamon and cayenne pepper. These have antioxidant, anti-inflammatory and antimicrobial properties and can help calm any inflammation in the body.
4. Water, Water, Water!
Staying hydrated helps your body naturally eliminate toxins as well as other bacteria that might cause illness. Aim for at least eight glasses of water a day, especially during these warmer months.
5. Get a good night’s sleep
7-8 hours of sleep can help bolster the T cells which fight infection in the body. One study showed that just one night of 4 hours’ sleep depleted the body’s natural killer cells by 70%.
6. Reduce stress
The brain and the immune system are in constant communication. When we are stressed, the brain produces more of the stress hormone, cortisol to deal with the perceived ‘emergency’, all the while reducing the effectiveness of our immune system. Try relaxation exercises like yoga or meditation and simple breathing exercises such as the 3-4-5 technique (breathe in for 3, hold for 4 and exhale for 5) can really help lower stress levels. Positive thinking can also help.
7. Eliminate or limit the bad stuff
Stress, processed foods, sugar, chemicals, pollution, smoking, lack of sleep, starvation diets can all take their toll on your immune system so do your best to create a more favourable environment for your immune system to thrive.
8. Eat a well balanced diet
To sum up, if you follow a low GL diet with lean protein, complex unrefined carbohydrates, healthy fats & plenty of multi-coloured fresh fruit and veg you could you be doing yourself a great favour.