Stay well all winter: Your ultimate immunity guide
Ah-choo! As cold and flu season approaches and winter bugs run rampant, we show you the best foods to boost your immunity.
They say you don’t catch a cold, a cold catches you. And it’s true. When your immune system isn’t functioning at its best, viruses, bacteria and their friends take over, and that tickle in your throat sets in.
The best way to prevent a cold is to arm your immune system with peak fire-power. A strong immune system is an asset you build up over time, but there are a few quick fixes that can help you stay well this winter. Here’s what you need to know!
Your immune system at work
Your immune system is a big network of cells, tissues and organs that work together to keep out harmful pathogens.
In winter these harmful substances can often be the viruses that end up causing chest infections, coughs, sneezes, colds and flus.
Your immune system starts with your skin, a physical barrier protecting your insides. Mucous membranes in your mouth and nose are another very important part of the system. Cells in your blood stream — plus tissues and organs including your lymph glands, your tonsils, adenoids and bone marrow — are all part of the immune system your body has set up to protect you.
Your immune system works tirelessly to defend you against bugs and sickness, but if you’re a little run-down, your body’s natural defence system can take a beating. Signs your immune system is rundown include:
Low energy levels
Cuts and wounds that are slow to heal
Recurring urinary tract infections
Difficulty shaking a cold
Why do we get sick more in winter?
Both in Australia and overseas, hospital admissions rise during the colder winter months.
Adults, on average, usually catch 2–4 colds every year. Children can get as many as 5–10, because they are not immune to many cold viruses.
Worryingly, Australia is also on track for a dangerous flu season, with doctors already reporting three times as many flu cases this year over last year.
We might expect the flu to be more pronounced in our colder regions — but that’s not the case.
It’s thought that when the colder nights hit, poor house insulation and heating offsets the potential benefit of living in a warmer area.
However colder weather does seem to increase the number of respiratory illnesses. And cold winter air is also a known trigger for asthma attacks. Some viruses thrive more in cooler winter temperatures — which means more flu, coughs and colds.
Vitamin D plays an important role in keeping your immune system healthy. Lower levels of vitamin D have been found in people with severe colds. The key to getting enough vitamin D is getting enough sun exposure — which can be harder in winter.
Keeping your windows shut and the heaters on in winter may also be making you sicker. A US study has found that increased air flow and a more humid environment was linked to lower virus levels.
Another study from China found that less fresh air coming into buildings could contribute to higher incidence of respiratory disease.
Should you feed a cold and starve a fever?
Feeling unwell often means you can lose your appetite, which is thought to be a way that the body protects itself. Studies suggest that fasting when the cause of your infection is bacterial could be beneficial, but not if your infection is viral. Many coughs and colds are viral — so feeding a cold seems to be the best approach.
Studies have shown fasting can help reduce inflammation, which often accompanies colds and fevers. But an increase in body temperature with a fever means you sweat more, losing fluid.
Dehydration can stop the immune system from working properly, so it’s important to take at least fluids when you have a fever. Dehydration also means the mucous membranes in your nose and throat dry more easily. It’s important to keep these membranes moist so your body can more easily remove the virus from your system.
So, unless you know what s causing your cold or fever, the answer seems to be: feed both.
Does vitamin C stop a cold sooner?
Taking an orange to work each day, or chewing vitamin C supplements, may seem like a great idea to keep winter colds away. Making this part of your daily routine may cut the duration and severity of your cold. But taking a vitamin C supplement when you’re already sick is likely to make no difference.
If you’re physically very active or at risk of having low vitamin C stores (for example, if you’re a smoker, have limited fruit and vegetable intake, or have a malabsorption condition), then you may benefit most from a regular vitamin C supplement, or foods that contain extra vitamin C, over winter.
Does a lemon, honey and ginger concoction work?
Nothing says ‘winter warmer’ more than the flavour combo of lemon, honey and ginger. But does this delicious drink keep sickness at bay?
Lemon adds a hit of vitamin C to the drink. Juicing one lemon yields about 27mg of vitamin C. On its own that’s not enough to reach your daily target, but combine it with an orange and a kiwifruit and you’re more than meeting the recommendations.
A systematic review has found honey to be just as effective as over-the-counter cough remedies for kids and adults — but don t give honey to children below the age of one, as it may have bacteria that can cause small infants to get very sick. Honey is high in antioxidants and has anti-inflammatory properties.
Ginger, like turmeric, has both anti-inflammatory and anti-microbial properties that may help stop a cough or cold.
However, it’s not clear yet just how much ginger you should put in your drink. Nevertheless, it looks like there's something in a lemon, honey and ginger drink that may help your cough or cold.
10 immune-boosting foods
Close to 70 per cent of your immune system is housed in your gastrointestinal tract, so looking after your gut health is key to winter wellbeing. Add these flu-fighting foods to your diet.
Regular omega-3 fats from oily fish such as salmon, tuna and sardines improve gut bacteria and have an anti-inflammatory effect. They are also a good source of vitamin D, which is essential for strong immunity.
Citrus fruits in general are bursting with vitamin C to support a healthy immune system. One orange provides your whole day’s vitamin C requirements.
A staple for winter cooking, crushed garlic releases a powerful compound, allicin, which has proven anti-bacterial properties. Garlic seems to be most effective when used as a preventative measure.
This furry fruit has just as much vitamin C as an orange, and is also packed with vitamin K, folate and potassium, to keep you fighting fit and healthy.
They’re packed with a mix of health-boosting antioxidants— so you really can’t afford to skip vegies when you’re sick. Chicken and veg soup, anyone?
Nuts & seeds
Filled with healthy fats — plus immunity-boosting zinc and vitamin E — nuts and seeds are an easy on-the-go-snack that really satisfies.
Winter vegies, like carrots, sweet potato and pumpkin, are rich in vitamin A, which keeps your digestive lining healthy to stave off infection.
Eggs are one of the highest natural dietary sources of vitamin D, with two eggs giving 82 per cent of your recommended daily intake. Plus, they’re an inexpensive, protein-rich brekkie!
Green and black tea varieties are high in disease-fighting antioxidants — and a cuppa of either will keep you warm and top up your fluid intake.
This sparkling fermented tea is high in gut-friendly probiotics. Choose a kombucha that is chilled and has a probiotics train backed by science.
How to keep the winter blues at bay
What can you do right now to keep coughs and sneezes from ruining your winter plans?
Eat plenty of fruit and veg
Fresh (or frozen) veg and fruit provide you with key vitamins, minerals and phytonutrients to keep your immunity strong.
Don’t miss out on fibre
Prebiotic fibres can benefit immune cells that live in your gut. Make sure you get plenty of vegetables, legumes and grain fibres in order keep your gut in its optimum condition during winter.
Drink plenty of fluids
Staying hydrated helps your immune system by boosting your skin health, mucous membranes and lymph fluid.
Get a daily probiotic hit
Probiotics, from food or via supplements, improve gut health, reducing the number and also the severity of respiratory infections.
Keep active outside
Being active is important for your mental health, with serotonin (the body’s own happy drug) increasing with regular activity. Outside activity also tops up your vitamin D.
Wash your hands
Following basic hygiene when those around you are coughing and sneezing can help minimise transmission of bad bugs.
Let the fresh air in
Open your windows and doors, when you can, to reduce germ transmission in your home
Stay at home if you’re sick
No one is indispensable, so if you’re sick, stay home, especially if your workplace is open plan.
Did you know?
Three in four Aussies eat less nutritious foods during the winter months