Five ways to help your immune system fight off the coronavirus

The best weapon we have against the coronavirus is inside us.

older couple in the kitchen

Clare Collins, University of Newcastle

The coronavirus presents many uncertainties, and none of us can completely eliminate our risk of getting COVID-19. But one thing we can do is eat as healthily as possible.

If we do catch COVID-19, our immune system is responsible for fighting it. Research shows improving nutrition helps support optimal immune function.

Micronutrients essential to fight infection include vitamins A, B, C, D, and E, and the minerals iron, selenium, and zinc.

Here’s what we know about how these nutrients support our immune system and the foods we can eat to get them.

Read more: What is a balanced diet anyway?

1. Vitamin A
Vitamin A maintains the structure of the cells in the skin, respiratory tract and gut. This forms a barrier and is your body’s first line of defence. If fighting infection was like a football game, vitamin A would be your forward line.

We also need vitamin A to help make antibodies which neutralise the pathogens that cause infection. This is like assigning more of your team to target an opposition player who has the ball, to prevent them scoring.

Vitamin A is found in oily fish, egg yolks, cheese, tofu, nuts, seeds, whole grains and legumes.

Further, vegetables contain beta-carotene, which your body can convert into vitamin A. Beta-carotene is found in leafy green vegetables and yellow and orange vegetables such as pumpkin and carrots.

2. B vitamins
B vitamins, particularly B6, B9 and B12, contribute to your body’s first response once it has recognised a pathogen.

They do this by influencing the production and activity of “natural killer” cells. Natural killer cells work by causing infected cells to ‘implode’, a process called apoptosis.

At a football match, this role would be like security guards intercepting wayward spectators trying to run on to the field and disrupt play.

Fish is a good source of vitamin B6. Shutterstock

B6 is found in cereals, legumes, green leafy vegetables, fruit, nuts, fish, chicken and meat.

B9 (folate) is abundant in green leafy vegetables, legumes, nuts and seeds and is added to commercial bread-making flour.

B12 (cyanocobalamin) is found in animal products, including eggs, meat and dairy, and also in fortified soy milk (check the nutrition information panel).

3. Vitamins C and E
When your body is fighting an infection, it experiences what’s called oxidative stress. Oxidative stress leads to the production of free radicals which can pierce cell walls, causing the contents to leak into tissues and exacerbating inflammation.

Vitamin C and vitamin E help protect cells from oxidative stress.

Read more: Coronavirus: it's time to debunk claims that vitamin C could cure it

Vitamin C also helps clean up this cellular mess by producing specialised cells to mount an immune response, including neutrophils, lymphocytes and phagocytes.

So the role of vitamin C here is a bit like cleaning up the football ground after the game.

Good sources of vitamin C include oranges, lemons, limes, berries, kiwifruit, broccoli, tomatoes and capsicum.

Vitamin E is found in nuts, green leafy vegetables and vegetables oils.

4. Vitamin D
Some immune cells need vitamin D to help destroy pathogens that cause infection.

Although sun exposure allows the body to produce vitamin D, food sources including eggs, fish and some milks and margarine brands may be fortified with vitamin D (meaning extra has been added).

Most people need just a few minutes outdoors most days.

People with vitamin D deficiency may need supplements. A review of 25 studies found vitamin D supplements can help protect against acute respiratory infections, particularly among people who are deficient.

5. Iron, zinc, selenium
We need iron, zinc and selenium for immune cell growth, among other functions.

Iron helps kill pathogens by increasing the number of free radicals that can destroy them. It also regulates enzyme reactions essential for immune cells to recognise and target pathogens.

Whole grain foods contain a variety of important nutrients. Shutterstock

Zinc helps maintain the integrity of the skin and mucous membranes. Zinc and selenium also act as an antioxidant, helping mop up some of the damage caused by oxidative stress.

Iron is found in meat, chicken and fish. Vegetarian sources include legumes, whole grains and iron-fortified breakfast cereals.

Zinc is found in oysters and other seafood, meat, chicken, dried beans and nuts.

Nuts (especially Brazil nuts), meat, cereals and mushrooms are good food sources of selenium.

Read more: Health Check: should I take vitamin C or other supplements for my cold?

Putting it all together
It’s true some supermarkets are out of certain products at the moment. But as much as possible, focus on eating a variety of foods within each of the basic food groups to boost your intake of vitamins and minerals.

While vitamin and mineral supplements are not recommended for the general population, there are some exceptions.

Pregnant women, some people with chronic health conditions, and people with conditions that mean they can’t eat properly or are on very restrictive diets, may need specific supplements. Talk to your doctor, accredited practising dietitian or pharmacist.

Read more: Social distancing: What it is and why it's the best tool we have to fight the coronavirus

And beyond diet, there are other measures you can take to stay as healthy as possible in the face of coronavirus.

Stop smoking to improve your lung’s ability to fight infection, perform moderate intensity exercise like brisk walking, get enough sleep, practise social distancing and wash your hands with soap regularly.The Conversation

Clare Collins, Professor in Nutrition and Dietetics, University of Newcastle

This article is republished from The Conversation under a Creative Commons license. Read the original article.

What are you doing to bolster your health against COVID-19?

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    To make a comment, please register or login
    23rd Mar 2020
    Some supermarkets have taken advantage and put their fresh veg prices right up. At ours yesterday $15 a kilo for broccoli, $11 each for a cauliflower, $9 for a lettuce. That doesn't make it easy does it?
    23rd Mar 2020
    I think there will be a lot who take advantage of this crisis. That is why the government is helping people on low incomes. People panicking also puts up the cost as they push the demand and make it a seller’s market.
    23rd Mar 2020
    Also, when I made an online order for Woolworths it was far more expensive than I have ever paid before. The specials are disappearing. They know we are frantic and desperate and many are rubbing their hands. I could get none of some items that we really need as well.
    Retiring Well
    23rd Mar 2020
    Coles don't even have a catalogue for next week. How are we supposed to work out what to eat?
    23rd Mar 2020
    That’s disgraceful price gouging.
    Name and shame on social media.
    The Thinker
    23rd Mar 2020
    That is disgraceful. The idea is to eat less healthy but no junk. Fill up on the fruits that grow wild there. I love mango.
    23rd Mar 2020
    A lot of the price rises are due to the drought and the bushfires which ruined or destroyed many of the crops.

    It is only now starting to wash through and that's why there are shortages and price rises. Veges usually take around 12-14 weeks to reach picking stage, so we're at that point now. Growers can only send to market what is available to pick and is of an acceptable quality for the consumer.

    I seriously doubt Coles and Woolies are going to destroy their reputations by profiteering. But corner shops and and others may not have scruples in that area. Like our best mate Gerry Harvey, the perennial retail whinger, he see's it as an "oppurtnity". His profits are way up - more fool the stupid people who buy his overpriced stuff.
    24th Mar 2020
    Grocery prices going up was in the plan and it is going to get worse.
    Start considering growing your own food .... just to survive ...
    23rd Mar 2020
    That is blatant profiteering - increasing grocery prices. First the drought, then bushfires and now the virus. I feel extremely sorry for those who were affected by the bushfires as well. This year has been hell for them.

    I hope sincerely that everything improves for them quickly. Stay well, everyone.
    Retiring Well
    23rd Mar 2020
    I don't want to fight it I want it now if I am to get it so that I'm over when the masses are supposed to get it.
    23rd Mar 2020
    Morrison telling us,we in it all together.
    Yes right tell Coles and woollies with jacking up their prices. SHARKS they are.
    The Thinker
    23rd Mar 2020
    I can't understand why the supermarkets aren't stocking up again. Hoarders aren't buying all the time and there are restrictions now. So why aren't they stocking up? Delivery trucks are everywhere on the roads.
    23rd Mar 2020
    Herr Docktor Professor Grabner says use warm salty water, rings throat thoroughly (gargle a little i you must), and syphon out sinuses... keeps the bugs down to a minimum and allows your bodily defences to work on any that get in rather than being overwhelmed.

    I've been mistaken for the professor of medicine at that young lass's university.
    29th Mar 2020
    My mum has been sniffing eucalyptus to clear your sinuses and feels it could prevent a bug settling in and setting up camp.

    24th Mar 2020
    Very good article.
    Walking in the fresh air and in the sun is good.
    Sweat it out and drink lots of liquid, especially hot liquid.

    The Wuhan virus is not heat resistant and will be killed at 26-27 degrees Celsius. Therefore, drink more hot water to prevent this disease. Walk more in the sun. Drinking hot water is a MUST. Although this is not a medicine, it will be beneficial to your body. Drinking hot water is effective against all viruses. Try not to drink icy-cold smoothies or eat ice-cream at all.
    In addition to frequent hand washing, it is highly advisable and beneficial to gargle with Betadine to eliminate or minimize germs that are still in the throat (before they begin to drip into the lungs), and to rinse the nose in the nostrils. Be very careful and drink as much water as possible.
    Take supplements: increased dose of vitamin C, vit. D together with K2, medicinal coal, zinc, selenium and magnesium. Eat garlic and onion. Lots of warm water with good squeeze of lemon.
    Turmeric and ginger.
    25th Mar 2020
    Hot water does nothing. By the time is reaches your stomach it is body temperature as is in fact iced water!

    Drink water yes. But don't think the temperature of it makes any difference.
    29th Mar 2020
    Yes been posting a lot of the same on many virus topics, Vitamin C, D and Zinc are the main ones. You may not be absorbing them enough through diet if you gut bacteria is not functioning correctly so it is a good idea to supplement now and through winter.
    For optimal immunity stay away from alcohol which lowers immunity, and only eat wholefoods with majority fresh fruit and veggies. Try shopping at farmers markets and small fruit and veggies groceries instead of the supermarkets.

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