Immunity-Boosting Foods That Help Fight Infections

One of the most important ways to stay healthy is to adopt habits that strengthen immunity. Getting enough sleep, managing stress, being active, washing your hands properly, and eating well all support your immune system.

While no food or supplement can “cure” or even 100% prevent you from catching a virus, like SARS-CoV-2, which causes COVID-19, or the flu, some foods help bolster immunity. 

Here are some immune-strengthening foods and how to incorporate them into your regular meals and snacks.

Citrus Fruits and Red Bell Peppers

Vitamin C, the superstar nutrient in citrus, is famous for supporting the immune system. While vitamin C can't prevent illness, it can shorten the length of a common cold. Vitamin C is necessary for your diet because your body doesn't naturally make the nutrient.

Vitamin C supports your immune system in the following ways:

• Protecting your DNA and your body's proteins, lipids, and carbohydrates from damage
• Making certain enzymes in your body work
• Getting infection-fighting cells to the infection site 
• Getting rid of cells that are done clearing an infection

You need to consume 100–200 milligrams daily to maintain a healthy level of vitamin C and reduce your risk of illnesses. One medium orange provides 70 milligrams, a medium grapefruit contains almost 80 milligrams, and a half cup of raw red bell pepper packs 95 milligrams.

Eat citrus as is, or pair it with nuts. Use sliced red bell pepper to scoop up hummus or guacamole, or make a salad with citrus and red bell peppers.

Sunflower Seeds and Almonds

Vitamin E also plays a key role in immunity by acting as an antioxidant. The fat-soluble vitamin boosts immune cell activity, which supports the body’s ability to fend off invading bacteria and viruses.

Adults should get 15 milligrams of vitamin E daily. One ounce of sunflower seeds, or a quarter cup, supplies nearly half of the daily recommended value. The same size portion of almonds contains 45% of the daily goal.

Pair with fresh fruit, or whip sunflower seeds or almond butter into smoothies.

Sweet Potatoes and Carrots

Sweet potatoes and carrots are top sources of beta-carotene, a precursor to vitamin A. Your body converts beta-carotene to vitamin A, a fat-soluble vitamin.

Beta-carotene aids the immune system in many ways, including:

• Helping produce white blood cells, which fight bacteria and viruses
• Supporting immune system cells, especially in clearing infections
• Regulating bone marrow
• Helping form mucous membranes that line the respiratory tract, the protective barrier that keeps germs out of the body

The amount of vitamin A you need varies, but the average adult needs 700–900 micrograms of retinol activity equivalents (RAE) daily. A baked sweet potato with skin packs over 150% of the daily goal. Also, one cup of raw carrots is over 100% of the daily recommended value.

Top a baked sweet potato with nuts or seeds, munch on carrots with healthy dips, like nut butter or tahini, or try a sweet potato and spinach quesadilla.

Brazil Nuts and Sardines

Selenium is an essential mineral that supports the following body systems:

• Endocrine
• Cardiovascular
• Immune
• Central nervous systems

When it comes to the immune system, selenium is a potent antioxidant. In other words, selenium protects your cells from being attacked in ways that damage DNA. Also, selenium makes activating certain types of cells in your immune system more efficient, especially regarding antiviral activity.

An adult needs 55 micrograms of selenium per day. One ounce of Brazil nuts, about six to eight whole nuts, provides nearly 1,000% of the daily recommended value of selenium. Also, three ounces of sardines provide over 80% of the daily goal.

You can eat Brazil nuts as is. Or chop and add them to oatmeal or cooked vegetables. Or, if you enjoy sardines, toss them with vegetables, tomato sauce, and pasta, or add them to salads.

Oysters and Pumpkin Seeds

Zinc is an essential nutrient that influences almost every system in your body. 

For example, zinc is necessary for the immediate and long-term response of the immune system. Specifically, the nutrient signals the activation of different immune system cells.

The recommended daily value of zinc is eight to 12 milligrams, varying by the person. Oysters have one of the highest amounts of zinc, giving you about 30 milligrams in three ounces. One ounce, or one-quarter of a cup, of pumpkin seeds contains 20% of the daily goal.

Combine the two: Broil or bake oysters as your protein source, paired with cooked vegetables sprinkled with pumpkin seeds.

Turmeric

People often use turmeric, a plant related to the ginger family, in curries for its vibrant color. Curcumin, the natural compound in turmeric, supports your immune system in several ways, like:

• Being a potent anti-inflammatory
• Interfering with enzymes and cells that cause inflammation in your body
• Boosting immune cell activity and enhancing antibody responses

However, eating turmeric on its own doesn't have any dramatic effect on your body. Your body poorly absorbs and rapidly clears up turmeric. In contrast, combining turmeric with black pepper significantly ups the benefits of curcumin. Black pepper's main ingredient, piperine, increases curcumin's bioavailability.

Sprinkle turmeric and black pepper into a smoothie, soup, broth, or cooked vegetables.

Dried Tart Cherries

The high antioxidant content in dried tart cherries helps bolster the immune system. Most commonly, people consume Montmorency cherries. The immune-system-related benefits of cherries include:

• Reducing the risk of upper respiratory tract symptoms
• Supporting healthy sleep, which is important for preventing illness, due to their natural melatonin content 
• Having high levels of vitamin C, carotenoids, and polyphenols, antioxidants that reduce or prevent inflammation.

Eat cherries as is. Or stir them into nut butter and eat off a spoon.

Walnuts

Walnuts are one of the top anti-inflammatory foods. Also, walnuts contain several nutrients that play a role in supporting the immune system, including:

• Vitamins E and B6
• Copper
• Folate
• Phytochemicals

What's more, research has found that walnuts reduce psychological stress, which weakens immunity.

Pair walnuts with dried tart cherries as a snack. Or chop them as a garnish for fresh fruit or cooked vegetables.

Garlic

Garlic is another food with anti-inflammatory properties. Garlic enhances the activities of enzymes that protect your cells and DNA.

According to one study published in 2016 in the Journal of Nutrition, healthy adults who consumed aged garlic extract for 90 days had enhanced immune cell function. 

People who consumed the garlic didn't experience fewer illnesses than the control group. Still, they had reduced severity, fewer symptoms, and a smaller number of missed days of school or work than the control group.

Reach for fresh garlic cloves rather than a supplement. Add garlic to cooked vegetables, soup, or broth.

Pomegranate Juice

Pure pomegranate juice supports immunity via its antimicrobial activity. Research has found that pomegranate juice's flavonoids, a compound with antioxidant properties, combat viruses. Specifically, those antioxidants decrease upper respiratory tract infections by 33% and the length of a cold by as much as 40%.

A study published in 2018 in the Alexandria Journal of Medicine found that polyphenols in pomegranate juice are also an effective anti-inflammatory in healthy older men. Polyphenols are compounds that include flavonoids.

Sip on pomegranate juice, or add splashes to water or chamomile tea. Or, blend into smoothies, or freeze in BPA-free molds, along with pureed banana and ginger root, to make popsicles.

Green Vegetables

Research has shown that green vegetables like kale, spinach, and broccoli strengthen the immune system.

Dark green vegetables are high in nutrients that have anti-inflammatory properties and help the immune system function, including:

• Vitamins A, C, E, and K
• Folate
• Carotenoids

Cruciferous vegetables, such as broccoli and Brussels sprouts, also provide bioactive compounds. Those compounds release a chemical signal that optimizes immunity in the gut, the location of 70% to 80% of your immune cells.

Sauté vegetables in extra-virgin olive oil along with garlic, turmeric, and black pepper, or add them to a soup. You can also blend leafy greens, like kale or spinach, into a smoothie.

A Quick Review

No food can 100% prevent you from catching a virus, but some can strengthen your immune system. Certain foods contain different vitamins and nutrients that support your immune system, helping you fight infections efficiently and quickly. Incorporate some of these foods into your regular meals or snacks.