How to Boost Your Immune System with Food

A diet rich in various fruits, vegetables, herbs and teas consists of a strong amount of antioxidants, substances that reduce oxidative stress by combating free radicals in the body and helping to fight inflammation. The three major antioxidant vitamins are beta-carotene, vitamin C, and vitamin E. These vitamins are found in colorful fruits and vegetables, especially in those with purple, blue, red, orange, and yellow hues. Other fat-soluble vitamins such as Vitamin D and A help to support immune function in the body. There are also minerals such as zinc and selenium that play a significant role in boosting immunity as well as the often termed “master antioxidant,” glutathione, which is composed of three amino acids. Lastly, probiotics are important to maintain healthy gut function which houses a significant amount of our immune system.

Vitamin C

Due to its antioxidant qualities, it may help to prevent bacterial and viral infections as well as shorten duration of colds. Some wonderful food sources of Vitamin C include: berries, leafy greens, cruciferous vegetables (broccoli, Brussels sprouts, cauliflower), citrus fruits, sweet potato, bell pepper and tomatoes.

Vitamin E

Avocado, leafy greens (chard, mustard and turnip greens, spinach), mangoes, nuts, papaya, pumpkin, red peppers, and sunflower seeds.
Beta-carotene and other carotenoids
Sweet potatoes, leafy greens, carrots, apricots, asparagus, cruciferous vegetables, beets, broccoli, etc.

Zinc

Zinc plays a significant role in boosting immunity. You can find significant amounts of zinc in oysters, red meat, poultry, beans, nuts, seafood, whole grains, some fortified cereals as well as dairy products. Zinc helps to create and activate white blood cells which are important for the immune response.

Selenium

Selenium is an important nutrient in immune function, serving as an antioxidant. It can be found in several foods including Brazil nuts (you only need two to achieve the recommended daily dose!), tuna, beef/poultry, fortified breads, mushrooms, and other grains.

Glutathione

Glutathione is one of the most important antioxidants that can be decreased due to poor diet, chronic disease, infection, stress as well as age. Some food sources to boost your glutathione levels include sulfur-rich foods including beef, fish and protein as well as vegetarian sources such as cruciferous vegetables like broccoli, Brussels sprouts, cauliflower, kale, watercress and mustard greens. You may also consider cooking with allium vegetables (garlic, shallots and onion) which all increase glutathione levels as well as prevent infection. Sip on some green tea or honeybush/rooibos tea throughout the day for an added glutathione boost in production and activity.

Probiotic Food Sources

You can find sources of probiotics in yogurt (dairy and dairy-free) as well as other fermented products. Probiotics help support a healthy gastrointestinal tract which houses the gut-associated lymphoid tissue (GALT) which is about 70% of your immune system. The health of the gut influences our immune system functioning. Find products that note “live and active cultures” as well as added vitamin D which is an immune system modulator.

Vitamin D

Vitamin D helps to support the immune system. While it’s important to get adequate amounts of sunshine to contribute to your Vitamin D levels, many people are deficient and may require D3 supplementation along with incorporating vitamin D rich foods such as liver, eggs, cheese, fatty fish and shitake mushrooms.

“Eat the Rainbow”

Brightly colored vegetables and fruits are shown to increase immunity due to their high phytonutrient content. Phytonutrients help to improve the stress response and lower systemic inflammation.
While we addressed a number of delicious and immune-boosting foods in the previous post, I want to emphasize the importance of consuming a wide-variety of colorful fruits and vegetables in order to fuel your body with a number of different vitamins, minerals and phytochemicals.

If you look down at your plate, the average standard meal consists of a lot of brown, yellow and white colors; in fact, it’s very common to be missing out on a phytonutrient color in one’s diet entirely. Aim for at least 9-13 servings of plant foods each day with a diversity in color. (One serving may be ½ cup cooked or 1 cup raw.)

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