Eat to Boost Your Immunity

Healthy immunity, nutritionally

Eating a nutritious and balanced diet is essential for maintaining optimal health, and one of its significant advantages lies in bolstering the body's natural immune system. A diet rich in vitamins, minerals, antioxidants, and other essential nutrients provides the necessary building blocks for a robust immune response. Consuming a variety of whole foods, such as fruits, vegetables, lean proteins, and whole grains, helps fortify the immune system by promoting the production and function of immune cells.¹ Moreover, a healthy diet contributes to maintaining a proper balance of gut bacteria, which plays a crucial role in immune function.² By making mindful food choices, individuals can enhance their overall well-being and create a resilient defense against infections and illnesses. The symbiotic relationship between a nutritious diet and immune health underscores the importance of adopting wholesome eating habits to support the body's innate ability to protect itself.

Start shoring up your body by seeking out and planning your menus with the following foods. 

Vitamins and minerals

Optimal levels of these micronutrients are linked to greater immunity, according to scientific studies. Research has also suggested that supplementing with key vitamins and minerals may support our natural immune system.*

Although a variety of foods play a role in boosting our immune system, foods containing vitamins, D, E, and C and the minerals, zinc, copper, and selenium appear to be particularly impactful. Along with taking supplements, you can glean these boons to your immune system from your diet.* Here are a few nutrient-rich foods, with the vitamins and minerals they supply:

• Fortified milk, eggs, mushrooms, tuna, salmon: Vitamin D

• Oranges, kiwi, red bell peppers, broccoli, spinach: Vitamin C

• Sunflower seeds, almonds, spinach: Vitamin E

• Shellfish, meat, poultry: zinc and selenium

• Seeds and nuts, whole grains, shellfish, chocolate: copper

Polyphenols

These compounds abundant in plants help activate our immune system to fight off any biological invaders that may negatively influence our health.* Plus, they encourage the growth of beneficial gut bacteria.* Research suggests that curcumin (in turmeric), allicin (in garlic), and gingerol (in ginger) are especially powerful. Here’s why: these polyphenols are both antioxidants (meaning they fight the free radicals that damage cells) and antimicrobials (meaning they keep opportunistic bacteria in check).* Here are a few polyphenol-rich foods, with an immunity-supporting micronutrient they include:

• Red grapes: resveratrol 

• Blueberries: anthocyanin 

• Dark chocolate: catechins, flavanol glycosides, anthocyanins, and procyanidins

• Green tea: catechin (epigallocatechin-3-gallate)

• Turmeric: curcumin 

• Garlic: allicin 

• Ginger: gingerol 

Probiotics and Prebiotic Foods

A large proportion of the immune system resides in the gastrointestinal tract. Basically, cells in the gut lining secrete antibodies (proteins produced by the immune system to fight foreign bodies, like bacteria). 

Probiotics (live microorganisms that benefit our health) stimulate the production of beneficial bacteria that help ward off harmful bacteria, according to research.*³ Several studies highlight how the lactobacilli and bifidobacteria varieties are particularly beneficial to the immune system.* As with vitamins and mineral-rich foods, research ties these organisms to a greater chance of health and wellness.* So, taking in probiotics can help empower our antibodies to protect ourselves. 

Eating probiotic foods can help you get enough of these live microorganisms. You can also feast on foods rich in prebiotics (indigestible plant fibers that “feed” probiotic bacteria). 

Probiotic foods:

• Yogurt or kefir with live active cultures

• Unpasteurized sauerkraut

• Tempeh

• Kimchi

• Miso

• Kombucha

Prebiotic foods:

• Apples

• Artichokes

• Sunchokes (Jerusalem artichokes)

• Asparagus

• Bananas

• Berries

• Flaxseed

• Garlic

• Green vegetables

• Leeks

• Legumes

• Oats

• Onions

• Tomatoes

Additional habits to adapt (or abandon) to support immunity

Stay hydrated consistently

Drinking an adequate amount of water is essential for overall health, including immune function. Water helps transport nutrients and ensures the proper functioning of various bodily processes. Keep a refillable bottle by your side and sip away.

Limit added sugars and processed foods

Excessive consumption of added sugars and processed foods can have a negative impact on immune health. These foods may contribute to inflammation and impair immune function, so it's essential to consume them in moderation.

Watch your alcohol consumption

If you drink, keep tabs on how much and how often. Excessive alcohol intake is considered four to five per day or 8-15 per week. This can weaken the immune system. If you consume alcohol, do so in moderation to support overall health.

Get sufficient vitamin D

Vitamin D plays a role in immune function, and sunlight is a natural source. It’s especially important during dark months to get outside whenever you can for some sun. Additionally, you can include foods like fatty fish, fortified dairy products, and vitamin D supplements if necessary.

Cooking to boost immunity

Most important, start with wholesome foods. Then prepare them in ways that retain or even amp up their nutrient content. Here are a few tips:

Source the freshest produce

Generally, the longer fruits and vegetables sit out after harvesting, the more nutrients they lose. To seek out goods picked as recently as possible, shop at a farmer’s market.

Consider combos

Certain nutrient-rich foods are more potent when paired. Here are some examples:

• Turmeric and black pepper (if buying a curcumin supplement, make sure it also includes black pepper) 

• Plant-based iron (in spinach and lentils) with Vitamin C (in citrus)

• Vitamin D (in salmon, tuna, egg yolks, and fortified milks) with calcium (in broccoli, collard greens, dried figs, and oranges)

• Incomplete proteins (proteins that do not include the full nine types of amino acids you need, like rice with black beans, hummus or peanut butter with whole-wheat pita, or quinoa and corn) 

Cook to keep nutrients

Try to avoid boiling veggies in water, since their nutrients can leach into the cooking water. Instead, steam or roast. Or simmer vegetables in liquid that you will incorporate into a dish, as with soups or stews. 

Cook fat-soluble vitamins in fat

Vitamins D, E, A, and K are fat-soluble, meaning they dissolve in fats. So, cook veggies with those micronutrients in oil or butter and include the fat as part of the finished dish. Think spinach sauteed in olive oil or mushroom soup, built on a base of onions, garlic, and mushrooms cooked in avocado oil.   

Triple your nutrition in one meal

Make triple (or even quadruple) threats or dishes that combine vitamins, minerals, polyphenols, probiotics, and prebiotics. Here are a few ideas:

• Indian dal (lentils): Saute onion, carrot, garlic, and ginger in avocado oil. Add lentils, tomato paste, broth, and curry powder (which includes turmeric), and bring to a boil. Cover and simmer until the lentils are cooked through. Serve topped with yogurt.

• Spinach salad: Toss fresh spinach with bell peppers, chopped eggs, and tomatoes. Toss with garlicky lemon vinaigrette, then top with toasted walnuts.

• Fruity oatmeal: Simmer oats with chopped bananas, flaxseed, and Vitamin D-fortified milk. Top with fresh berries, a dollop of yogurt with live active cultures, and toasted pecans.

• Muesli: Stir together rolled oats, yogurt, milk, flaxseed, golden raisins, diced apple, and chopped grapes; top with toasted nuts 

• Shrimp and broccoli stir-fry with garlic, ginger, and cashews, served with kimchi

• Quinoa, corn, spinach, tomato, and avocado salad 

• Hot ginger-turmeric tea with lemon, black pepper, and honey

• Bowl with black beans, brown rice, fajita vegetables (bell peppers, onions, and garlic sauteed in olive oil), topped with yogurt and guacamole

• Fruit salad with kiwi, orange, grapes, and berries sprinkled with toasted nuts and seeds

Originally published: July 25, 2022

Updated: Jan. 8, 2024

References:

¹ Childs CE, Calder PC, Miles EA. (2019). Nutrients. 2019 Aug 16;11(8):1933. doi: 10.3390/nu11081933. PMID: 31426423; PMCID: PMC6723551.

² Wu HJ, Wu E. (2012). Gut Microbes. 2012 Jan-Feb;3(1):4-14. doi: 10.4161/gmic.19320. Epub 2012 Jan 1. PMID: 22356853; PMCID: PMC3337124.

³ Haghighi HR, Gong J, Gyles CL, Hayes MA, Zhou H, Sanei B, Chambers JR, Sharif S. (2006). Clin Vaccine Immunol. 2006 Sep;13(9):975-80. doi: 10.1128/CVI.00161-06. PMID: 16960107; PMCID: PMC1563569.

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