It’s that time of year again — the dreaded cold and flu season.
You could completely remove yourself from society and avoid all human contact, but there are much more reasonable things you can do to look after yourself!
One of the foundations for a healthy immune system is adequate nutrition.
Your immune system needs enough energy, protein, vitamins and minerals to function normally. While good nutrition can’t guarantee that you won’t catch a cold or flu, it can help provide the nutrients your immune system needs to do its job.
Here are five easy additions to consider during the cooler months.
1. Look After Your Gut
Your gut and immune system are closely connected.
The gut contains a large amount of immune tissue, and the microorganisms living in your digestive system interact with your immune system in many ways.
Researchers have also investigated whether specific probiotic strains can reduce the risk or duration of respiratory infections. Some studies suggest they may offer a modest benefit, particularly for upper respiratory tract infections.
What about yoghurt?
Some fermented dairy products have been studied for their potential effect on respiratory infections.
When choosing yoghurt, look for products that indicate they contain live cultures.
Not every yoghurt contains live microorganisms, and there’s no need to search for a particular number of “billion bacteria” unless you’re specifically looking for a clinically studied probiotic product.
You can also include other fermented foods you enjoy, such as:
- Kefir
- Kimchi
- Sauerkraut
- Tempeh
- Natto
Remember that fermented foods are not automatically probiotic foods. The specific microorganisms and their potential health effects vary between products.
The bigger picture is to regularly include a varied, fibre-rich diet to support your gut microbiome.
2. Add Zinc-Rich Foods
Zinc is an essential mineral that your body needs for normal immune function, wound healing and many other processes.
Good food sources include:
- Beef
- Chicken
- Seafood
- Eggs
- Dairy foods
- Chickpeas
- Beans
- Nuts
- Seeds
- Wholegrains
- Fortified breakfast cereals
Getting enough zinc through your diet is important for maintaining normal immune function.
What about zinc when you have a cold?
Zinc has been studied more extensively for what happens after a cold starts than for preventing colds.
Some research suggests that zinc lozenges or syrup taken soon after symptoms begin may shorten the duration of a cold. The results vary depending on the formulation, dose and timing.
For everyday immune nutrition, however, focusing on zinc-rich foods is a sensible place to start.
High-dose zinc supplements aren’t something most people need routinely and can cause side effects when taken in excess.
3. Fill Your Plate With Vitamin A- and Vitamin C-Rich Foods
Vitamin C is well known for its role in immune health, but vitamin A is important too.
Vitamin C contributes to normal immune function and acts as an antioxidant.
Rather than taking large doses of vitamin C, focus on regularly including vitamin C-rich foods such as:
- Capsicum
- Broccoli
- Kiwifruit
- Oranges and other citrus fruit
- Strawberries
- Tomatoes
- Cabbage
Vitamin A helps maintain normal immune function and supports the body’s protective barriers.
Good sources include:
- Eggs
- Dairy foods
- Liver
- Carrots
- Sweet potato
- Spinach
- Other dark green vegetables
- Mango
Plant foods such as carrots and sweet potato provide beta-carotene, which the body can convert to vitamin A.
An easy strategy
Instead of counting individual vitamins, aim to include a variety of colourful fruit and vegetables every day.
4. Add Garlic for Flavour
Garlic contains sulphur-containing compounds that have attracted interest because of their antimicrobial and other biological properties.
But even if garlic can’t guarantee that your cold disappears, it is still a fantastic addition to your diet.
It adds plenty of flavour without needing large amounts of salt and can make nutritious meals more enjoyable.
Try adding garlic to:
- Pasta sauces
- Stir-fries
- Soups
- Roast vegetables
- Homemade dips
- Wholegrain toast
- Salad dressings
And yes, it can still keep the vampires away!
5. Look After Your Vitamin D
Vitamin D plays important roles in your bones, muscles and immune system.
One common misconception is that everyone needs a specific amount of sunshine each day to maintain vitamin D levels.
There is no universal “30 minutes of sun” rule.
Vitamin D production from sunlight varies according to the season, time of day, latitude, skin pigmentation, cloud cover and other factors.
In Australia, it’s also important to balance vitamin D production with protection from excessive UV exposure.
Food can contribute vitamin D too.
Sources include:
- Oily fish such as salmon, sardines and mackerel
- Egg yolks
- Some fortified milks
- Some fortified margarines
- UV-exposed mushrooms
- Other fortified foods
If you’re concerned about your vitamin D levels, speak with your GP about whether testing or supplementation is appropriate.
What About Supplements?
It’s easy to feel like you need a cupboard full of supplements when cold and flu season arrives.
But supplements aren’t automatically better than food.
They can be useful when someone has a nutrient deficiency, increased nutritional requirements or another specific clinical reason. For most people, however, a balanced diet is the best foundation for immune nutrition.
A food-first approach also gives you a combination of nutrients, fibre and other beneficial food compounds rather than one isolated nutrient at a time.
Don’t Forget the Other Defences
Nutrition is only one part of protecting your health during cold and flu season.
Don’t forget to:
- Wash your hands regularly
- Cover coughs and sneezes
- Stay home when you’re unwell
- Avoid sharing cups and utensils
- Keep vaccinations up to date, including influenza vaccination where appropriate
- Get enough sleep
- Stay physically active
These simple habits work alongside good nutrition.
What Could a Cold-Season Day Look Like?
You don’t need to turn your diet upside down.
Breakfast
- Wholegrain oats
- Milk or yoghurt
- Kiwifruit or berries
- Pumpkin seeds
Lunch
- Wholegrain sandwich or wrap
- Chicken, tuna, egg or chickpeas
- Spinach
- Capsicum
- Tomato
Snack
- Yoghurt containing live cultures
- Fruit
- A handful of nuts
Dinner
- Salmon or lean beef
- Brown rice or another wholegrain
- Broccoli
- Carrots
- Garlic
- Extra virgin olive oil
This provides protein, zinc, vitamins A and C, fibre and a range of other nutrients that support a healthy dietary pattern.
Take Home Message
The cooler months don’t have to mean spending the whole season feeling unwell.
You can’t guarantee that you’ll avoid every cold or flu, but you can give your immune system a strong nutritional foundation.
Rather than looking for one miracle “immune-boosting” food, focus on the bigger picture:
Include zinc-rich foods. Eat plenty of colourful fruit and vegetables. Choose fibre-rich plant foods. Enjoy yoghurt with live cultures or other fermented foods you like. Eat vitamin D-containing foods. Use herbs and spices such as garlic to make nutritious meals enjoyable.
And remember that good nutrition supports normal immune function — it doesn’t make you invincible to infections.
Small, consistent habits throughout the year are much more useful than waiting until you feel a cold coming on.
How Feed Your Future Dietetics Can Help
Nutrition advice can become particularly confusing during cold and flu season, with social media promoting everything from “immune-boosting” powders to megadoses of vitamins.
At Feed Your Future Dietetics, I help you separate evidence-based nutrition from the latest health trends and develop practical strategies that fit your lifestyle.
Whether you’re looking to improve your overall nutrition, support your immune health, manage a health condition or simply build a more balanced eating pattern, personalised dietetic support can help.
With over 10 years of experience supporting Australians with their nutrition and health goals, Feed Your Future Dietetics provides individualised dietetic support Australia-wide via Telehealth using Zoom or Microsoft Teams.
To learn more or book an appointment:
ashleigh@feedyourfuturedietetics.com
References
- Zhao Y, Dong BR, Hao Q. Probiotics for preventing acute upper respiratory tract infections. Cochrane Database of Systematic Reviews. 2022.
- Mohseni H, et al. Effect of probiotic fermented dairy products on incidence of respiratory tract infections: a systematic review and meta-analysis of randomized clinical trials. 2021.
- National Institutes of Health, Office of Dietary Supplements. Dietary Supplements for Immune Function and Infectious Diseases.
- National Institutes of Health, Office of Dietary Supplements. Zinc Fact Sheet for Consumers.
- National Institutes of Health, Office of Dietary Supplements. Vitamin C Fact Sheet for Consumers.
- Australian Government. Nutrient Reference Values – Zinc.
- Australian Government. Nutrient Reference Values – Vitamin A.
- Australian Government. Nutrient Reference Values – Vitamin C.
- Australian Government. Nutrient Reference Values – Vitamin D.
- Lissiman E, Bhasale AL, Cohen M. Garlic for the common cold. Cochrane Database of Systematic Reviews. 2014.
- Cancer Council Australia. Information on vitamin D, UV exposure and sun protection.
- healthdirect Australia. Colds.
