Health Lifestyle Wellness

Immune Boosting Foods to Add to Your Diet

By Marianne Hudson, Dietitian at MACROS

With the cold and flu season upon us, and COVID cases back on the rise, now is an especially important time to prioritise your immune health. For those of us in the Southern Hemisphere shorter and cooler days can mean that we’re spending more time indoors, and less time being active and getting in that much needed vitamin D! In the northern hemisphere, the transition into spring can bring seasonal colds.

When its cold diets can also naturally start to shift towards warmer, heavier, and more comforting foods. The lack of essential nutrients can increase our susceptibility to infection, and our ability to fight it off. So what can you do to optimise your immune health? And can you actually ‘boost’ your immune system?

You can’t boost your immunity, you can support it

Despite popular belief, you can’t literally ‘boost’ your immune system beyond its capability, but you can definitely support it to ensure it is working at its optimum! Building a healthy immune system isn’t just about fighting infection when it hits, it’s about building the foundations over time to support your body’s ‘immune fitness’ so that it’s ready for battle if and when infection strikes.

How to build a strong immune system

So, how do we build a strong immune system? Sure, getting a good night’s sleep and regular exercise is important, but it’s also crucial to ensure you’re consuming key dietary components for immune function, and there’s evidence to suggest that vitamins C, D, E, zinc, iron, selenium, and omega 3 play an important role. Interestingly, up to 80% of your immune system is actually located in your digestive system – so your gut health is the powerhouse for an optimally functioning immune system.

Whilst it’s unlikely that individual foods offer special protection, consuming a well-balanced diet can prime your immune system with the right mix of tools (immunonutrients) to ensure it is working at its best! With that in mind, here are my top eight immune supporting food groups to keep you fighting fit this winter.

1. Probiotic Foods

Probiotic rich foods are great for gut health, and the research shows that healthy gut bacteria actually support our bodies to build and maintain a strong immune system. Think fermented foods like Greek yoghurt (which provides Lactobacillus and Bifidobacterium), sauerkraut, kimchi, pickles, kefir, miso and tempeh.

2. Prebiotic Foods

Think of prebiotics as the food for your probiotics (good gut bacteria). Prebiotics are found in fibre and resistant starch rich foods like wholegrains, fruits, vegetables and legumes. Think rolled oats for breakfast, beans in salads, soups and curries, and vegetables such as broccoli, cauliflower, garlic and leeks.

3. Vitamin C Rich Foods

A single kiwifruit provides you with your daily requirement for vitamin C, and citrus fruits are also an abundant source, and in peak season! Other high vitamin C foods include: broccoli, capsicum, berries and chilli peppers.

4. Omega 3 Rich Foods

Research has shown that omega 3 can help to support optimal immune health. Fish and seafood are best sources of omega 3, with oily fish such as salmon, sardines, and mackerel being some of the highest in omega 3 content. If you follow a plant-based diet, I’d recommend regularly including walnuts, chia seeds, flaxseeds, spinach and edamame.

5. Nuts

Nuts provide a rich source of minerals, and they make for some great snacking. I recommend cashew nuts for a rich source of zinc, Brazil nuts for selenium, and almonds for a hit of vitamin E.

6. Iron Rich Foods

Whilst we know red meat is rich in iron, there are plenty of great veg alternatives, including green leafy vegetables, kidney beans, lentils, chickpeas, and nuts like pistachios and cashews. Including a source of vitamin C with these foods will also boost your iron absorption!

7. Vitamin D Rich Foods

We now know that vitamin D has an important role in immune function, and around 30% of adults have inadequate levels of vitamin D. Top up your stores with vitamin D mushrooms – leave some mushrooms in the sun for an hour and they will produce the vitamin D for you to eat! Other dietary sources of vitamin D include fortified dairy products, eggs and fish like salmon and tuna.

8. Protein

Proteins are the building blocks for just about everything in our bodies – including the immune system. Think lean meats, eggs and fish, or legumes, lentils and nuts for plant-based options. These foods are also generally rich in zinc and iron. If you struggle with getting enough protein in or are unsure of how much to consume, leave it to the experts. Meal delivery services like MACROS offer specifically formulated meals which are high in protein, to ensure you are meeting individual requirements. If you’re unsure how well you’re meeting your daily macros (pun intended) try a home-delivered meal plan and see how you feel physically and mentally following the healthy change in diet.

Happy eating, and remember, a strong and healthy immune system will be better equipped to defend you compared to one that is tired, depleted or deficient in nutrients.

About Marianne Hudson

Marianne Hudson is an Accredited Practising Dietitian & Exercise Physiologist with over 10 years of experience in the health and food industries. Marianne is passionate about evidence-based nutrition, food innovation and individualised health advice, all of which is a valuable part of her current role as MACROS Lead Nutritionist. Follow Marianne on Instagram @foodforfight.


MACROS ready-made meals make healthy eating easy and delicious for every Aussie. Nutritionally-balanced and portion-controlled, MACROS meals are dairy-free and cater to a range of dietary requirements, also offering pre-planned guides to help you achieve your wellness goals.

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