We are not all equally susceptible to these viruses or to bacterial infections. Our inbuild immune system is designed to help protect us and we have various mechanisms the immune system can activate to fight the incoming pathogens. But to work effectively it needs the right food and nutrients.
The key nutrients your immune system needs are:
Studies have shown that those with vit D deficiency have an increased risk of catching the flu. You make vitamin D in your skin on exposure to sunlight, so you’d think we have no problem in a sunny country like Australia. However, sunscreen use, time spent indoors, covering up to protect your skin from sun damage or in line with your religion, all mean that many of us are in fact vitamin D deficient.
Foods to boost vitamin D
Eggs – make sure you eat the whole egg as the yolk is where you’ll find the vitamin D.
Oily fish – such as salmon, mackerel, trout, sardines and herring.
Wild mushrooms or commercial varieties exposed to sunlight – you can do this yourself or look for specially produced mushrooms.
Fortified foods – some milks, yoghurt & cheese have vitamin D added. This will be on the label.
Good old vitamin C is such a common little nutrient I feel we take it for granted. The trouble is that we cannot store it so you actually need to consume it every day to keep your levels optimal. It plays a key role in immune function, enhancing the production and efficacy of our infection-fighting white blood cells.
Although research has been mixed, there is no doubt of the role of vitamin C and most studies conclude that taking in sufficient helps to reduce the severity and length of a respiratory infection. There may be some benefit to taking high levels once you are sick – 1000mg three times a day – but meantime it’s worthwhile ensuring you include vitamin C rich foods every day.
Foods to boost vitamin C
Fruit – pretty much all fruits contain vitamin C. Those that rank especially high include guava, kiwi fruit, berries, citrus (oranges, grapefruit, lemons and lime).
Capsicums & chilli
Leafy greens – especially when you eat them raw as cooking results in some loss of vitamin C. You can limit this by avoiding boiling in water and not overcooking. Just wilt your leafy greens.
Broccoli & Brussels sprouts
You might have noticed that lozenges to treat coughs and colds often contain zinc. That is indeed based on the science. Studies have shown that zinc lozenges can reduce the duration of an upper respiratory tract infection by 20-42%.
That’s because zinc is a key mineral required for many metabolic processes including those of the immune system. If you are low on zinc, you are more likely to pick up an infection and you will take longer to get rid of it and to heal.
While a zinc lozenge is a good idea once you are sick, you are best not to take supplements regularly as minerals compete for uptake and you can upset your body’s balance. Instead ensure you are eating plenty zinc-rich foods.
Foods to boost zinc
Oysters – the standout food for zinc, head and shoulders above all the rest! If you don’t like oysters, mussels and other shellfish are next in line.
Fortified breakfast cereals – most are fortified with zinc but check the label to be sure. Opt for wholegrain cereals to boost your fibre and keep refined starch and added sugars to a minimum.
Red meat – we are in an era where the push is to eat less meat and more plants. However, there is no getting away from the fact that red meat is a terrific source of both iron and zinc… and both are essential for immune function.
Nuts – All nuts provide some zinc, with Cashew nuts boasting the highest levels, followed by pine nuts, Brazil nuts, pecans and almonds.
Wholegrains – zinc is found in the outer layers of the grain and so refined grains like white rice have very little zinc. Opt for wholegrains and products made from them to get your zinc along with the complement of antioxidants, other nutrients and fibre these foods provide. For example, look for black or wild rice, rye bread or crackers and wholegrain pasta made from durum wheat.
Legumes – good sources of zinc include peanut butter (yep peanut is a legume) and peanuts, baked beans, lentils, dried beans, soybeans, tofu & lupin.
This is our key antioxidant mineral and it also plays a role in immunity. Animal studies have shown that where selenium levels are low, the severity of a flu virus is much worse. In humans ensuring a sufficient intake of selenium has been shown to strengthen immune function.
Foods to boost selenium
Brazil nuts – the clear-cut winner when it comes to selenium. Just 3 Brazil nuts a day gives you the boost you need. Other nuts give you much, much smaller, but still significant levels with cashews scoring considerably higher than other tree nuts.
Eggs – an excellent source of selenium with a serving of 2 eggs providing about 41% of your daily requirement.
Kidneys – OK not everyone’s cup of tea, kidneys have lost their appeal to many in our culture. Nevertheless, they are, like liver, highly nutritious and they do give you a pretty fabulous selenium boost. I leave that one with you.
Mollusks – that means mussels, octopus, cuttlefish and the like. Develop a diverse appetite for seafood as they have much to offer nutritionally as well as from culinary prespective.
Our major fat-soluble antioxidant vitamin that works in concert with vitamin C. In short you need adequate levels to fight infections (and to age well and look after your heart I might add).
Foods to boost vitamin E
Almonds – all nuts contain significant levels of vitamin E, but almonds win this one by a long shot. Hazelnuts and pine nuts are the next in the running.
Extra virgin olive oil – because it is mostly monounsaturated fat, the vitamin E in olive oil is highly available – it is not used up protecting fragile polyunsaturated fats as it is in seed oils. You get the added benefit of the antioxidants in the oil.
Seeds – sunflower seeds are awesome for vitamin E. You can also include sesame seeds and tahini.
Eggs – wining again due to their vitamin E content. You’ll find it in the yolk so be sure to egg the whole egg.
Avocado - olives and avocado are the two fruits that provide helthy fats and they both provide vitamin E. Ensure some avo most days.
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