Maintaining a healthy immune system is key to fighting off germs. The best way to do that is by consuming immune-boosting foods.
Leafy greens like spinach, kale and collard greens provide vitamin C, folate and antioxidants. They also contain compounds called glucosinolates and quercetin, which protect against cancer.
Other immune-boosting nutrients include zinc, vitamin E and selenium. Try to get these nutrients from whole foods instead of supplements.
Green Tea
Green tea is rich in catechins, a type of polyphenol that offers multiple health benefits. One test-tube study found that EGCG can inhibit the process of hemagglutination, which is how viruses enter cells and are then transported throughout the body.
The delicate drink also increases the frequency of “regulatory T” cells, which are responsible for controlling immune responses and suppressing autoimmune diseases. More research is needed in people with weakened immune systems and larger sample sizes, however.
While green, black, white and oolong teas come from the same evergreen plant (Camellia sinensis), differences in processing, geographic locations and plant varieties influence their nutritional makeup and flavor. Some herbal teas, such as our calming Chamomile and turmeric-rich Anti-Inflammatory, may be better for immune support than others.
Vitamin D
Many people seek out special foods or vitamin supplements that are believed to boost immunity. While there are some foods that do enhance immune function, it is important to remember that a well-functioning immune system requires a balance of nutrients and lifestyle factors.
The vitamin C found in citrus fruits like oranges, kiwis and grapefruit, as well as leafy green vegetables and dark berries, is a great immune booster. Likewise, tomatoes are rich in the antioxidant lycopene.
Oily fish is also a great source of omega-3 fatty acids, which are known to support the function of T cells, which help to fight off disease-causing pathogens such as viruses and bacteria. They are also good for lowering the risk of autoimmune diseases, where the body’s immune system mistakenly attacks healthy tissue.
Mushrooms
Mushrooms are a healthy addition to any meal because they contain many essential nutrients. They also help balance the microbiome in your digestive tract and fuel the growth of good bacteria. They have anti-inflammatory properties and provide a natural source of vitamin D. They also contain polysaccharides, which activate parts of the immune system and increase ‘natural killer’ cells. Mushrooms are rich in antioxidants and contain a variety of B vitamins and selenium, which fight free radicals in the body that can damage cells and tissues.
Mushrooms are low in calories and provide the body with protein, potassium, zinc, phosphorous, iron and calcium. However, some mushrooms do contain purines, which break down to form uric acid that can cause health problems in certain people.
Cruciferous Vegetables
This group of vegetables, which includes cauliflower, Brussels sprouts, broccoli, cabbage, kale, collard greens, bok choy and arugula, provides a powerhouse of nutrients. They are high in vitamin C, folic acid and potassium. They contain the plant compounds glucosinolates (sulfur-containing chemicals) and indoles, which have been shown to fight cancer.
While their taste can sometimes be off-putting, they are versatile and can be roasted, sauteed or grilled. They are often eaten raw in salads or slaws and are also delicious mashed into a pizza crust or pureed into a smoothie. They are low in calories, provide a healthy dose of fiber and fight inflammation. Berteroin, which is found in cabbage, rucola salad leaves and mustard oil, reduces LPS-induced proinflammatory responses in macrophages. (PLoS One, 2013). The anti-inflammatory effects of cruciferous vegetables are also beneficial for autoimmune diseases and inflammatory conditions like rheumatoid arthritis.
Yogurt
Yogurt is a fermented dairy product made by mixing milk or cream with characterizing bacteria (Lactobacillus bulgaricus and Streptococcus thermophilus). The bacteria produce lactic acid, which thickens the milk proteins and gives yogurt its distinct tart taste. The bacterial cultures in yogurt can also boost gut health by increasing the production of appetite-reducing hormones peptide YY and GLP-1.
For best results, choose plain low-fat or whole milk yogurt without added sugar. Look for a variety with a minimum of 1 million CFUs or colony-forming units per serving, which is the standard required by the FDA for yogurt to be labeled as “live and active.” Sprinkle on granola for an immune system-boosting breakfast or use as a base for creamy sauces. Try adding a handful of nuts or seeds for a nutrient boost— Brazil nuts are rich in selenium, which improves immune function.