5 foods to help support a healthy immune system

Trying to avoid a cold, the flu, or a virus? Here’s the real science behind some popular immune boosting foods.
Published 11 March 2020 | Updated 1 July 2024

Discover the power of food in bolstering your immune system against colds, flu, and other viruses. While hygiene is crucial for preventing illness, certain foods can also play a significant role in supporting immune health. Explore the scientific evidence behind immune-boosting foods and learn how to incorporate them into your diet for optimal wellness.

1. Chicken soup

Tend to reach for a bowl of chicken soup whenever you feel run down? It’s no wonder: Chicken soup may provide a mild anti-inflammatory effect that appears to lessen the severity of cold symptoms, according to a study published in the peer-reviewed journal Chest. Researchers credit ingredients like veg, which are rich in vitamins, minerals, and antioxidants, for helping to reduce inflammation. Although the jury is out on the ideal soup recipe and exactly how much soup to consume, researchers believe that simply sipping the warm liquid can help improve upper respiratory tract symptoms. So while you shouldn’t necessarily forgo cold medicine in favour of chicken soup, it can contribute to your get-well plan. Bonus: It serves up a dose of fluids and satisfying protein to both help you meet your nutrient needs and stay on track when you’re under the weather, says registered dietitian Jackie London.

2. Citrus fruits

Oranges, grapefruits, lemons, and limes are a great source of vitamin C, a potent antioxidant that plays a role in immune cell functioning (i.e., helps keep your immune system in good shape), according to a 2015 review article in Chemistry Central Journal. That said, peeling a single orange won’t do much to prevent you from getting sick or shorten the length of a cold. Developing a habit of eating a range of foods that contain vitamin C as well as a variety of antioxidants—like citrus fruits— can support overall health, according to a 2017 study review published in the journal Nutrients. Researchers also found that vitamin C deficiency is associated with impaired immunity and higher susceptibility to infections.

Another caveat: Eating an orange beats drinking a glass of orange juice, since fruit is higher than juice in fibre, antioxidants, phytonutrients, and prebiotics, all of which support health, London says.

Citrus recipes

Incorporate more citrus into your meals with these recipes:

3. Yoghurt and other probiotics

The gastrointestinal tract and the trillions of bacteria that live there account for up to 60 per cent of the entire immune system, says board-certified gastroenterologist Brittany Seminara, MD.

Generally, the gut’s naturally-occuring bacteria aid in digestion and keep the lining of your gut healthy. However, medications, infections, illness, and other environmental factors (like what you eat) can disturb the balance of gut bacteria—one reason why it may be smart to consume beneficial bacteria known as probiotics, which are available as supplements or in foods like yoghurt and fermented items like kefir, kimchi, miso, and sauerkraut.

On probiotic-containing dairy products in particular: While a common myth suggests that dairy increases mucus production and can do more harm than good when you’re already feeling under the weather, rest easy: Research suggests this isn’t true, London says.

Probiotic recipes

Amp up your probiotic intake with these dishes:

4. Legumes and foods with prebiotic fibre

Fibre, or carbohydrates that pass through the digestive tract to promote healthy digestion and elimination, is an essential part of a nutritious diet. Eating prebiotic fibre, a type that helps to feed the healthy bacteria found in your gut may play a role in supporting immune system functioning. Foods containing prebiotic fibre include legumes, onions, leeks, garlic, wholegrains (including oats), cashews, soy, and fruits such as bananas.

Prebiotic fibre-rich recipes

Enjoy more gut-friendly prebiotic fibre with these recipes:

5. Seafood and foods high in zinc

A nutrient that is essential for proper immune system functioning, zinc is found in a whole bunch of tasty foods including oysters (the best source of zinc per serving), mussels and other seafood, yoghurt, milk, poultry, red meat, legumes, nuts, and wholegrains. And while most people get enough zinc through their diet, when you’re trying to out run a virus, supplementing with zinc (at least 75 mg per day) from the onset of a cold until it’s gone could help you feel better faster, according to a meta analysis of seven randomised controlled trials featuring 575 participants who’d been diagnosed with colds.

Zinc-rich recipes

Amp up your zinc intake with these zinc-infused meals:

The bottom line

If you really want to help the body maintain a healthy immune system, maintaining a diet rich in wholegrains, fresh fruits and vegetables, lean meats, fish, eggs, and dairy year-round —particularly during cold and flu season—is vital Dr. Seminara says. It’s also worth repeating: Make sure to wash your hands properly (i.e., with soap for at least 20 seconds) and keep them away from your face; avoid others who are sick; and disinfect places or objects touched by many people (like door handles, phones, and keyboards) before using them. Paired with a balanced diet rich in essential nutrients, these habits can help you stay well.