The Best Foods to Bolster Your Immune System

We’ll cut to the chase: No food, drink or supplement can prevent an infection. What you feed your body does have a huge impact on your overall disease-fighting ability, however.

“Our immune system is complex and involves many different organs and cells throughout our body, which act like an army ready to defend any pathogenic organisms or foreign invaders. Nutrient-dense foods that are high in antioxidants, phytochemicals, vitamins and minerals all help the body to regulate and optimize its immune system,” explains Mary Stewart, RD, LD, the founder of Cultivate Nutrition in Dallas.

She compares nutrient-dense foods to wearing a seat belt in a car. While the seat belt will not prevent you from getting into an accident, it can reduce the chances of being injured as the result of that accident. Similarly, consuming an immune-supporting diet will not prevent foreign invaders from entering your body, but it can give your body the strength and tools it needs to fight them off. 

It’s not just about diet, though, adds Rania Batayneh, MPH, the owner of Essential Nutrition For You and author of The One One One Diet: The Simple 1:1:1 Formula for Fast and Sustained Weight Loss. Exercise, age, stress and genetics also play a big role in the efficiency of your immune system. 

“Maintaining a healthy weight supported by a diet filled with nutritious whole foods, fruits and vegetables, limiting alcohol consumption and avoiding smoking will positively influence your overall health, allowing your body’s systems to function well,” Batayneh says.

Vitamin C, vitamin E, vitamin A, vitamin D, omega-3 fatty acids, selenium and zinc are all immunity superstars, according to the International Food Information Council (IFIC). But there’s no one magical nutrient to seek out in the foods and drinks that you include in your immunity-bolstering meal plan. The beneficial micronutrients in whole foods work together to optimize immune function, Stewart says, so the simplest approach is to eat a variety of foods found in nature. 

7 of the Best Foods to Support Your Immune System

As a general rule, aim to limit processed foods, added sugars, alcohol, refined carbs and soda, as these may all contribute to chronic inflammation, harm immune-supporting healthy gut bacteria or speed up the aging process—all of which can weaken immune defenses. 

For the best diet for your immune system, seek out unprocessed or minimally-processed foods and drinks, eat a wide variety of colors and load up on herbs and spices. Stewart and Batayneh are particularly fond of these seven staples.

Yogurt

About 70 percent of the body’s immune cells reside in the gut, according to research published in the journal Clinical & Experimental Immunology.

“Foods with probiotic and prebiotic properties are key to creating a healthy gut. Greek yogurt with live and active cultures is a great way to get your daily dose of probiotics,” Stewart says.

Oats 

So what about prebiotics? Oats offer them, along with a type of fiber called beta-glucan, which has been shown to have antimicrobial and antioxidant properties. Several studies have proven that this fiber may increase the body's immune response—especially in relation to upper respiratory infections, Batayneh explains.

Blueberries 

Bonus points if you go for wild blueberries, which are one of the most antioxidant-rich foods on the planet. (Wild berries deliver twice as many antioxidants as cultivated blueberries.) They also contain plant compounds like anthocyanins to help reduce inflammation and enhance immunity, plus blueberries offer 24 percent of the recommended daily intake of vitamin C, an important nutrient in immune support, Stewart says.

Mushrooms 

Fungi in any form have been shown to increase the production and activity of white blood cells, making for a healthier immune system, according to Batayneh. Maitake, reishi, shiitake and lion’s mane mushrooms in particular seem to be beneficial to help the body fight off certain diseases such as influenza and certain cancers.

Kale 

These dark green leaves—or any other cruciferous vegetable like cauliflower, cabbage, collard greens, or Brussels sprouts—offer vitamin A, vitamin C and vitamin E, all of which are micronutrients that support proper immune function. These veggies also support your liver in the processes of producing glutathione, which acts as a master antioxidant that helps to regulate immune function, Stewart says. 

Sweet Potatoes

The connective tissue that constructs the skin is the first line of defense against invading pathogens. Sweet potatoes are extremely rich in vitamin A (only second to beef liver as a dietary source, per the National Institutes of Health (NIH) Office of Dietary Supplements), a nutrient that plays a role in the development of these vital connective tissues, Batayneh says.

Nuts and Seeds

The healthy fats in nuts and seeds assist your body in absorbing the fat soluble and immune-regulating vitamins in other foods, such as vitamin A, vitamin D and vitamin E. 

“Brazil nuts, specifically, are a good source of selenium, zinc and vitamin E, key nutrients for immune health,” Stewart says.