9 foods to boost your immune system

Updated June 2024 | 5 min read 
Expert contributor Natasha Schilling, accredited practising dietitian, Dietitians Association of Australia  
Words by Charmaine Yabsley 

Give your body the best chance of keepings colds and flus away with these nine immune-boosting foods. 

It tends to be more common to catch a cold or flu during the colder months, so it’s important to eat a wide range of foods to help boost your immune system and give it the best chance to fight off any nasty bugs.

While it’s tempting to reach for comfort food when it’s cold outside, try to include some of the suggestions below to boost your immunity and help you to stay cold-free this winter.

1. Eat seasonally

Natasha Schilling, an accredited practising dietitian and spokesperson for Dietitians Australia, recommends eating seasonal fruit and vegetables, as they’re more likely to be full of the nutrients you need.

“Seasonal fruit and vegetables pack a punch nutrient-wise,” she says. “If you eat seasonally, you’re going to give your body a fantastic set-up to get through winter because seasonal fruits like apples, pears and citrus, including grapefruit, mandarins and oranges are at their peak of nutrition.”

Winter vegetable options include broccoli, cauliflower, carrots, mushrooms and spinach.

2. Meat

“Lean poultry, like chicken, turkey breast with skin removed and lean red meat, are proteins that have a good amount of iron and zinc in them, which is important for the immune system,” she says. “We find that when people have low zinc levels, their immune system suffers.”

If you eat red meat, don’t go for the supersized ribs. Keep your serving size in mind – ideally a 90 to 100g raw/65g cooked serving size, which is about the size of the palm of your hand. For white meat, like chicken and turkey, one serving is a little more – around 100g raw/80g cooked.

3. Oily fish

“Oily fish like salmon, tuna and sardines have omega-3 fatty acids in them, which are essential for a healthy immune system, as well as vitamins A, D, B6 and B12,” says Natasha. “And sardines have little bones which contain calcium.”

If you’re a fish eater, aim to have it two to three times a week. “Fresh, frozen or tinned are good,” says Natasha. “If you buy tinned fish then choose those in spring water as this will reduce your sodium [salt] intake.”

4. Nuts

“A fantastic snack or an addition to a meal, nuts contain protein and healthy fats and are a really good source of vitamin E, which is needed for a strong immune system,” says Natasha.

It’s best to choose raw and unsalted nuts, she says, otherwise you may unknowingly be doubling your sodium intake.

“Roast nuts in the oven and add extra flavour with spices like cumin, garlic or chilli.”

Be careful not to overdo serving sizes, though. “You should aim to eat around 30g of nuts a day. A serve is a small handful, which is about 30 almonds, or four chestnuts, or 15 cashews.”

5. Rolled oats

Oats contain beta-glucan, a type of soluble fibre, which has immune-boosting properties and can help your body to fight infection. 

Add oats to a morning smoothie or soak them in water or apple juice overnight and heat them in the morning. “Add some Greek yoghurt, berries for sweetness and cinnamon. Or make an oat crumble for a winter dessert with stewed fruit,” she says.

6. Greek yoghurt

“Full of B vitamins and folate and calcium, there’s also a lot of good bacteria in yoghurt,” says Natasha.

The good bacteria, found in good-quality yoghurts, may support immune function, digestion and the absorption of nutrients, and help fight against unfriendly bacteria.

Although plain yoghurt is also good for you, Greek yoghurt is likely to have less sugar and more protein.

Add to breakfasts or have as a dessert, with a teaspoon of honey and winter berries added for extra sweetness. “Or use as a replacement for sour cream, which has a lot of saturated fat,” says Natasha.

7. Garlic                                          

“Garlic is a little powerhouse,” says Natasha. “It contains the antioxidant allicin, which has antibacterial properties and may help immunity and reduce your risk of catching colds.”

“Garlic has a beautiful flavour and is quite warming, so you can add it to most [savoury] meals,” she says. “Add a couple of cloves as a base to sauces, dishes, or roast a whole garlic and squeeze it out on sourdough bread.”

8. Green tea

“We often forget that what we drink can help boost our immune system,” says Natasha. “Green tea contains a whole lot of polyphenols – antioxidants – which [can help] protect the body’s cells against damage.”

Remember that green tea still contains caffeine, although it’s much lower than coffee. Decaf green tea is thought to have similar potential health benefits.

9. Chicken soup

It may be good for the soul, but it might also help if you have a cold. A study published in the journal Chest reported that chicken soup may have anti-inflammatory properties that can help to stave off upper-respiratory tract infections.

“[Almost] any type of homemade soup is a fantastic way to get a lot of vegetables into your diet, and keep your hydration levels up, since the fluid adds to your water intake.”

Natasha recommends adding a rainbow of vegetables into your soup to keep your immune system strong. “We get different nutrients and vitamins from each colour,” she says.

“Try Thai pumpkin soup, minestrone with pasta and lentils, beans or pulses, chicken and corn soup, or potato and leek,” she says. “Use winter veg you may not eat otherwise, such as turnips, swede and parsnips.”