Immune-Boosting Foods for Preventing Cold and Flu

Flu season is upon us, and our immune systems need to be working at full capacity to keep infections and viruses at bay. The most effective way to give your body the edge it needs to ward off infections is including immune-boosting foods in your diet.

Our immune system fighters require consistent nourishment to thrive. Vitamins, minerals and antioxidants are the building blocks of a healthy immune system and are essentially what make the body resilient.

Immune-boosting foods

Researchers have long recognized that micronutrient deficiencies — for instance, deficiencies of vitamin C and D, zinc, selenium, iron, and folic acid — compromise immune responses in people. Evidence points out that malnourished people are more susceptible to infectious diseases than people without serious nutrient deficiencies.

Immune-Boosting Foods to Fight Colds and Flu

Most colds are caused by viruses, but fever, shaking, and chills could mean you have a bacterial infection. Foods with antibacterial and antiviral properties can help protect you against pathogens lurking out there.

Chicken Soup

You may think of it as an old wives’ tale, but there’s actually some science to using chicken soup to prevent and treat colds. A study that used blood samples from participants showed that chicken soup inhibits the migration of infection-fighting white blood cells known as neutrophils, and that by doing so it basically helped alleviate upper respiratory cold symptoms.

According to another study, chicken soup also stimulates the function of the cilia (nasal hair) which prevents pathogens from entering the body.

Vitamin D

A vitamin D deficiency puts you at risk for many health conditions, and a compromised immune system is one of them.

A study published in the American Journal of Clinical Nutrition shows kids who took vitamin D supplements every day were 40 percent less vulnerable to the common flu virus than children who were given a placebo. Research shows vitamin D can assist immune cells to identify and kill pathogens that make us ill.

Vitamin D deficiencies are pretty common, and it’s difficult to get adequate amount of vitamin D from diet alone, so supplements are recommended. You can also get minor doses of vitamin D from fatty fish, such as mackerel and salmon.


There’s no denying the medicinal benefits of garlic. The vegetable bulb has been used for thousands of years by cultures across the world for its antibacterial and antiviral properties.

Garlic’s owes its immune-boosting abilities to allicin – the compound that gives it its characteristic smell. Allicin is the key antibacterial constituent of garlic. Garlic is also a great source of nutrients, such as vitamins B1, B6 and C, iron and magnesium.

Best eaten raw or in a capsule, garlic can be effective as a preventative medicine against colds and other respiratory infections, especially during the flu season. A study published in Advances in Therapy found that participants who took garlic supplements for 12 weeks got fewer colds than those who were given a placebo. There isn’t a recommended daily intake for garlic, but experts advise eating 1-4 cloves, which equals to 4,000 mcg of allicin, to reap its medicinal benefits.


It’s no wonder turmeric has a long history of use for medicinal purposes – the spice has the highest antioxidants and anti-inflammatory properties. Curcumin, the active ingredient in turmeric, is anti-viral and anti-bacterial, making it an excellent defence against colds.

As a powerful antioxidant with anti-inflammatory properties, turmeric can help treat chronic illnesses and ward off common infections like the flu. Turmeric is most effective it its raw form, and if consumed with black pepper, the chances of your body absorbing it increase significantly.

Immune-boosting Foods

Green Tea

Green tea boasts many benefits, and polyphenols are believed to be what give green tea its health-boosting properties. Studies show polyphenols (potent plant oxidants) help restore immune system function.

A specific type of polyphenols known as catechins are also credited with destroying flu viruses. To make the most of its protective effects, green tea should be steeped in hot water for no more than two minutes. You can add honey and lemon to counter its bitterness.


Shellfish such as oysters, lobsters, mussels and crabs are a rich source of selenium. Selenium helps white blood cells create cytokines — proteins that play an important role in immune response using mechanisms against the invading pathogens.

The immune-boosting benefits of selenium are supported by studies concerning ageing immunity. Your ideal dose of shellfish should be two servings a week.


Ginger is known to activate T-cells, a type of white blood cells that play a major role in immune system function. T-cells can destroy cells infected with a virus. Like garlic, ginger also has antibacterial and anti-inflammatory properties, and encourages the body’s natural defence against pathogens.


According to a University of Florida study, shiitake mushrooms have potent immune-boosting properties. Study participants who ate cooked shiitake mushrooms every day for four weeks had better functioning T-cells and declines in inflammatory proteins. Mushrooms are known to raise the production and activity of white blood cells.

Shiitake, maitake, and reishi mushrooms are most effective at boosting immunity.


Yogurt, sauerkraut, and pickles have one thing in common – they’re packed with immune-boosting probiotics.

Probiotics contain live bacteria cultures that keep the gut and intestinal tract healthy. Live bacteria cultures in probiotic and fermented foods move to your gut and maintain the balance between healthy and harmful bacteria.

Healthy bacteria present in the body can help fend off infections. According to a study, children who consumed probiotics, suffered fewer colds, were treated with fewer antibiotics, and missed fewer days of school than children who were not given probiotics.

Probiotic supplements are useful, but research shows a daily serving of yogurt is just as effective in improving immunity as popping probiotic pills.


Before the discovery of penicillin, honey was a standard defence against infections. With its antibacterial and antiviral properties, there is sizeable evidence to back the claim that honey is a potent immunity booster.

It has a variety of medicinal properties, and is a common remedy for coughs and sore throats.


Small as they may be, blueberries are antioxidant powerhouses that confer a host of health benefits – including improved immunity.

A study by researchers from Oregon State University showed pterostilbene, a compound found in blueberries promotes the body’s ability to fend off infections, when combined with vitamin D. Studies also show blueberries have the most potent antioxidant content than any other fruit.

Citrus Fruits

Research shows the benefits of using vitamin C as a remedy to prevent colds are a bit exaggerated, but studies do show that taking a vitamin C dose when an infection is still in its infancy can help reduce the duration of a cold.

The human body doesn’t produce or store vitamin C — foods and supplements are the only way to introduce this powerhouse nutrient into your body. Citrus fruits are packed with vitamin C, so reach for an orange or grapefruit when you need a strong dose.

Multivitamin Supplements

If you have a micronutrient deficiency or you just can’t get behind eating these healthy foods, you may need to compensate with multivitamin supplements. There’s no substitute for a balanced diet, but multivitamins can satisfy your micronutrient needs and offer nutritional insurance. Consult your doctor to find out if you have any deficiencies and what supplements you need to make up for them.

Rumana Dsouza

Rumana D’Souza is the social media and content coordinator for Prizm Media and Kudolife. She has found her life’s calling in writing about health and wellness, and believes she can make the world a touch healthier – one blog post at a time.

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