Foods that Support Immune Health

How to Boost Your Immune System through Diet

Research shows that several foods support the immune system and battle against the inflammation triggered by stress or common illnesses. Chances are you’re already eating many of the following foods. If not, now is a good time to try something new.

1. Antivirals 

  • Garlic. Garlic is an effective antiviral, antifungal, and antibacterial,1 making it a go-to ingredient for a healthy immune system. Research shows that garlic helps reduce the severity of cold and flu symptoms.2 Chop or crush the cloves – which helps convert alliin to allicin, the protective element in garlic ­– and add to sauces, soups, appetizers, or whatever you’re cooking.
  • Red peppers. High in vitamin C, red bell peppers and hot chili peppers have antimicrobial properties that protect against viruses and other microorganisms.3 
  • Shiitake mushrooms. Eating shiitake mushrooms increases the levels of natural killer cells and immunoglobulin A, two important immune system components for fighting off viral attacks.4 

2. Anti-inflammatories

Viruses, like the common cold and influenza, cause inflammation in the body. That inflammatory response is sometimes a double-edged sword: While it helps the body fight off infection, it can also cause serious problems that can contribute to lung damage and even death. Many research studies suggest that modulating the inflammatory response could be key to improving health outcomes.5 

In addition, experiencing stress can cause an inflammatory response in the brain, which triggers the release of glucocorticoids, a class of steroid hormones.6 If you remain in a state of chronic stress, your body can suffer from long-term inflammation – which can increase the risk of heart disease7 and is associated with a higher risk of cancer, diabetes, and other chronic conditions.8-10 Foods that show anti-inflammatory properties include:

  • Turmeric. A spice widely used in cooking in India and derived from a ginger-family perennial plant, turmeric packs a double punch as both an anti-inflammatory and an antioxidant.11 Turmeric provides a polyphenol known as curcumin. Polyphenols are a group of compounds high in antioxidants that are found in plant foods like fruits, vegetables, whole-grains, and nuts. Curcumin has been well studied for the health benefits it provides, including the ability to suppress inflammation and help manage conditions such as arthritis, anxiety, and exercise-induced muscle soreness.11 It has also been shown to help memory and mood.11  
  • Ginger. Available in powdered form or fresh in the produce section of grocery stores, ginger root contains a substance called gingerol, which has been shown to help inhibit inflammation.12 Some studies have found that gingerol improves cardiovascular disorders and gastrointestinal health and helps reduce exercise-induced muscle pain.12 
  • Fish and nuts. Omega-3 fatty acids – mostly found in fatty fish and some nuts – play an important role in regulating the body’s inflammatory process.13 Research has shown that including omega-3s as part of your diet helps improve outcomes for a range of conditions like heart disease, kidney problems, and autoimmune disorders.13 Add these omega-3-rich foods to your shopping list:14
    1. Salmon, tuna, trout, and mackerel
    2. Walnuts, pecans, flaxseed, and chia seeds
    3. Plant oils, including soybean oil, flaxseed oil, and canola oil
    4. Foods fortified with omega-3s, including some eggs, juice, milk, and soy beverages

3. Gut microbiome boosters

Many research studies have explored the impact that diet can have on a healthy gut microbiome – the complex gastrointestinal ecosystem made up of trillions of viruses, fungi, bacteria, and other bugs. A healthy gut ecosystem supports the body’s immune function.15 Because food directly affects these microorganisms, either encouraging or suppressing their growth, researchers have explored which foods support a healthy microbiome.16 Some of these foods include17:

  • Fermented foods, including yogurt, sauerkraut, kombucha, and kefir 
  • Whole-grain, high-fiber foods
  • Monounsaturated fats, such as olive oil
  • Polyphenol-rich foods, including fruit, vegetables, seeds, tea, cocoa products, and wine

Generally,  the Mediterranean diet, which includes healthy fatty acids, fruits, vegetables, fiber, and smaller amounts of protein, is associated with a healthier gut microbiome.17 

4. Foods high in antioxidants

Antioxidants are necessary to decrease inflammation and fight off disease.10 They can be consumed in the foods you typically eat or from supplements.

Three key antioxidants – zinc and vitamins C and D – play crucial roles in helping protect the body’s cells from damage.18 Learn more about which supplements can help support optimal immune function.* (insert link to first article in series)  

Antioxidants are commonly found in just about all types of fruit and dark, leafy greens. Most salad greens, kale, and spinach include vitamins A, C, E, K, and folate, as well as high levels of fiber and immune-supportive minerals.19 These foods are also low in carbs, sodium, and cholesterol, making them a quadruple win.19

Protect yourself with healthy food 

When you’re feeling stressed or sick, it’s common to forgo eating a healthy diet. But eating the right foods can have a sizeable impact on boosting immunity and decreasing inflammation in your body.10 

And the reverse is true, too: unhealthy foods – especially processed sugars – have been shown to increase levels of C-reactive protein, a biomarker of inflammation in the blood.20 There’s no magic solution that will cure every virus – but a healthy diet is your best first line of defense.

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Doctor of Clinical Nutrition | Certified Nutrition Specialist