The air is turning crisp, the days are growing shorter, and suddenly you feel that all-too-familiar tickle in your throat. Before long, a cough creeps in — and just like that, the flu strikes. Not again, you sigh.
Seasonal changes often put our immune systems to the test, leaving us more vulnerable to colds and flu. But don’t worry — whether you’re already feeling symptoms or simply looking to strengthen your defences, the right foods can make a real difference. And the good news? You don’t have to eat chicken soup for the next 10 days! There are plenty of other foods that can give your immune system a lift and get you back on track.
In this article, we’ll explore some of the most effective flu-fighting foods, clear up a few common health myths, and share practical tips to help you stay strong and healthy throughout the autumn months.
Can food really fight the flu?
You might wonder why we should pay attention to what we eat when there are plenty of medicines and other remedies available. The answer is simple: our diet is one of the richest sources of natural support for the body, helping increase the amount of goodness we take in and keeping us strong.
There is a clear link between the food we consume and the health of our body’s defence system. Vitamins and minerals from our diet provide the essential building blocks our body needs to fight off infections. A well-nourished immune system means a lower risk of falling ill.
This becomes especially important during the colder months, when viruses spread more easily and our body’s defences are naturally weakened. That’s why it’s vital to look after your diet throughout autumn and winter, especially if you’re already battling with the flu.
What the science says
1. Food can fight off disease
Your immune system needs good nutrition to work well. The food you eat provides different nutrients (macronutrients and micronutrients) that help your body fight off infections in different ways.
Macronutrients
Macronutrients are nutrients your body needs in larger amounts, like proteins, carbs, and fats.
- Proteins have building blocks called amino acids that help your immune cells grow, multiply, and fight off germs.
- Healthy fats, like omega-3s, help immune cells send defence messages and reduce harmful inflammation. You can find omega-3s in oily fish like salmon and tuna, or in seeds like flaxseeds and chia seeds.
Micronutrients
Micronutrients are nutrients your body needs in smaller amounts, like vitamins and minerals.
- Examples include vitamin A and zinc. These nutrients help immune cells grow, reduce inflammation, and support balanced immune activity, which can influence symptoms such as swelling and fever.
Eating a balanced diet with the right mix of macronutrients and micronutrients, especially those that support your immune system and reduce inflammation, helps keep you strong and healthy during the colder months. (1)
2. A poor diet can increase the risk of flu
Diets low in essential nutrients and high in ultra-processed foods can weaken your body’s defences, making it harder to fight infections like the flu. Without enough vitamins, minerals, and protein, immune cells cannot function properly, and important organs involved in immunity may shrink.
Overeating and obesity can also harm immunity by promoting chronic inflammation, increasing the risk of infections, and can even reduce how well vaccines work.1
Want to learn more about the link between diet and disease?
Our everyday food choices are linked to our long-term health, including the risk of chronic conditions like heart disease, type 2 diabetes, and some cancers.
Read our article Food for health: how diet can prevent disease to find out more.
Ultra-processed foods— like ready meals and packaged snacks — are often low in fibre because processing removes the healthy parts of grains.
Eating too little fibre can upset the good bacteria in your gut, meaning there are fewer of them. And an unhappy gut means an unhappy defence system, increasing your risk of getting ill.2
3. Gut health is important for immunity
Your gut is really important for keeping your immune system strong. It contains a large part of your immune system, and the bacteria in your gut help modulate how your body reacts to infections.
These bacteria also help break down nutrients that your body can’t digest on its own.3 Signals from the microbes are needed for the immune system to develop properly, and the immune system helps keep the gut bacteria healthy.
Get all the facts on gut health and how it can improve your health here: Gut health 101: Why it matters and how to improve it.
Flu-fighting foods
Eating a variety of nutrient-rich foods is one of the best ways to keep your immune system strong through the colder months. Instead of looking for a single “miracle” ingredient, focus on whole, seasonal foods like citrus, root vegetables, leafy greens, and fermented foods. These provide a steady mix of vitamins, minerals, protein, and healthy fats — all of which help your body fight infections, calm inflammation, and recover faster.
Here are some top flu-fighting foods to include in your diet:
Citrus fruits
Oranges, lemons, red bell peppers and grapefruits are well-known for their vitamin C content. Vitamin C protects immune cells from damage and helps them destroy germs. Without enough of it, you’re more likely to pick up colds and respiratory infections.1
But, how much is enough? Do not fear! You don’t need to be eating 10 oranges a day.
The recommendation is 75 mg of vitamin C per day for women, and 90 mg for men. 1 orange a day or half a bell pepper is plenty to help you meet your daily needs for vitamin C!
Red or purple fruit and veg
Berries, red cabbage, and other brightly coloured produce are packed with antioxidants, which help reduce inflammation and keep your body’s defences strong.4
Leafy greens
Spinach, kale, and other leafy greens are great sources of vitamin A and fibre. Vitamin A keeps the linings of your skin, gut, and lungs healthy — your first barrier against germs — while also supporting antibody production.1
Starchy fruit and veg
Apples, bananas, artichokes, and asparagus are high in fibre and prebiotics. These feed the “good” bacteria in your gut, which in turn support a strong immune system.5
Yoghurt and fermented food
Foods and drinks like yoghurt, kombucha, sauerkraut, kefir, and kimchi contain probiotics — live bacteria that help balance your gut and support immunity. They may even reduce the length of colds or respiratory infections.6
Oily fish, seeds and quinoa
Salmon, sardines, tuna, mackerel, as well as chia seeds, and flaxseeds, provide omega-3 fatty acids.7 These healthy fats help regulate inflammation and support immune balance.6
Fish like tuna provide both iron and omega-3 fatty acids, which support oxygen transport and reduce inflammation. Plant-based options like quinoa and pumpkin seeds are also rich in iron, making them great choices for boosting energy and supporting a healthy immune system.1
Salmon is also rich in selenium and vitamin D.8 9 Selenium helps the immune system fight infections, reduces inflammation, and supports antioxidants , while vitamin D strengthens immune cells, controls inflammation, and may lower the risk of infections like flu and COVID-19.10 1
Looking for vegan or vegetarian alternatives? Brazil nuts, whole-grain or fortified bread, and mushrooms are all great sources of selenium.
The sun is your best friend when it comes to vitamin D
Even though vitamin D can be found in foods like salmon and some mushrooms, sunlight is the best way to get vitamin D.
So, make sure to soak up what you can during the colder months when the sun isn’t around as much, always while being responsible and using sunscreen.
Chicken soup
More than comfort food, chicken soup provides hydration, iron and protein. Protein, made up of important amino acids, is essential for building immune cells, powering antibodies, and reducing inflammation.10
Nuts
Almonds and other nuts are rich in zinc and vitamin E. Zinc is essential for developing healthy immune cells and fighting infections, while vitamin E helps protect cells from damage and keeps your immune system running smoothly.6
Plus, walnuts are a great source of omega-3 fatty acids, supporting immune balance.7
Herbs and spices
Garlic, ginger, and turmeric don’t just add flavour — they contain natural plant compounds, called phytochemicals, that reduce inflammation and give your immune system an extra boost.11
Phytochemicals are natural compounds that plants use to protect themselves from germs like viruses, bacteria, and fungi. When we eat foods rich in these compounds, we can benefit too — they help reduce inflammation and support our own immune defences.12
Water & Green Tea
Staying hydrated is key for overall wellness. Water is always best, but green tea also provides antioxidants that support your immune system.6
Honey
Honey has natural antibacterial properties thanks to its sugars, plant compounds, and enzymes. It can soothe a sore throat while also helping your body fight off germs.13 That’s why you’ll often find medicines containing honey!
Six myths about food and immunity
Everywhere you look, there’s advice on “immune-boosting” foods, supplements, and quick fixes — but not all of it is true. Let’s bust some of the most common myths about immunity.
Myth 1: eating “superfoods” will magically boost your immune system
Not quite! While nutrient-packed foods are definitely important, there’s no quick fix. The real secret? A consistent, balanced diet full of fruits, vegetables, and wholesome foods. That’s what keeps your immune system running at its best.
Myth 2: cutting out all sugar makes your immune system super strong
Too much added sugar isn’t great, but completely cutting it out isn’t realistic — or necessary — for most of us. The better move? Focus on whole foods, limit sugary drinks and processed snacks, and give your body the carbs and energy it needs to thrive.
Myth 3: supplements are the only way to support your immune system
Not true! A well-rounded diet is your best friend when it comes to immunity. Supplements like vitamin C, D, or zinc can help if you have a specific deficiency — but they shouldn’t replace a healthy, nutrient-rich diet. You can find these nutrients naturally in food!
Do you need supplements to boost your immune system? Find out here: The vitamin myth: do we really need vitamin supplements?
Myth 4: “detox” diets will supercharge your immune system fast
Restrictive detox or cleanse diets often leave you missing key nutrients and can even do more harm than good. Instead, let your body do its thing naturally with a balanced diet, plenty of fruits and veggies, and good hydration. Try intuitive eating for a less restrictive, more positive way of eating.
Myth 5: loading up on vitamin C is the key to staying healthy
Your immune system is complex and needs a variety of nutrients. Focusing on just one, like vitamin C, won’t give you full support. A balanced diet with vitamins and minerals like zinc, vitamin D, and vitamin C is the real way to keep your immunity strong.
Myth 6: if you eat perfectly, you’ll never get sick
Even the healthiest eaters catch colds sometimes — that’s just life. A good diet helps your body fight off germs and recover faster, but sleep, stress, exercise, and other lifestyle factors all play a role too.
How to beat the flu this season
Nutrition supports your immune system but doesn’t replace vaccines, rest or good hygiene. If you’re already feeling under the weather, eating the right foods might not prevent a cold, but they can help you recover faster. If flu symptoms are severe or persistent, seek professional guidance.
Think of food as support, not a silver bullet: small changes, like eating more whole foods and reducing ultra-processed products, can make a significant difference. There’s no single food, supplement, or “quick fix” that can magically stop the flu. Eating a variety of nutrient-rich, whole foods — like fruits, vegetables, nuts, oily fish, and fermented goodies — gives your immune system the steady support it needs to fight off infections and bounce back. Pair that with good sleep, regular movement, hydration, and hygiene, and you’re setting yourself up for a stronger, healthier season. Think of food as your body’s everyday armour: consistent, balanced choices will always beat last-minute “immune hacks.”
