At all times of the day, your body is exposed to bacteria, germs and viruses that are trying to invade and attack your body.
Your intricate immune system works like a personal military system, armed and ready to defend you from these foreing invaders that cause harm.
With a healthy immune system, even if an infection invades your bodies, it’s usually a matter of time before it can fight it off.
To support your troops and get your immune system “serving” you with strength, it’s fundamental to focus on the right fuel.
Here are the top 21 superfoods for boosting your immune system:
Citrus Fruits (limes, lemons, oranges, clementines)
Berries (Strawberries, blueberries, raspberries)
Tea (green and black)
Red Bell Pepper
Cruciferous Vegetables (Broccoli, Brussels sprouts, Cabbage)
Leafy Greens (Spinach, arugula, microgreens)
Nuts (almonds, walnuts, cashews)
Fatty Fish (salmon, tuna, herring)
Shellfish (oysters, clams, mussels, lobster, crab)
Poultry (chicken, turkey)
Seeds (chia, pumpkin, sunflower)
Beans (red, pinto, navy, black)
We’re going to explore these immune-boosting superfoods in more detail below, but keep in mind that not all of these foods may be good for your body. If you have an allergy or sensitivity, skip them!
Additionally, at the end of this article, we’re going to discuss nutrition and immunity more generally, and provide a list of what you should and shouldn’t include in your diet.
21 Superfoods for Boosting Your Immune System
Incorporating these foods in your daily routine will help keep your body energized and healthy. These leading superfoods are packed with vitamins and minerals that will help your body fend off germs and help you perform at your best. Aim to sneak them into your diet whenever possible.
1) Citrus Fruits (limes, lemons, oranges, clementines)
Citrus fruits are packed with vitamin C which can help create white blood cells. Since vitamin C is water soluble, your body can’t store it. So it’s important to eat vitamin c containing foods on a regular basis.
One cup of orange juice contains about three oranges! Since too much sugar can decrease immunity, it’s best to go for the whole fruit whenever possible.
Add a squeeze of lemon or lime juice to your water or tea for a vitamin C boost.
2) Berries (strawberries, blueberries, raspberries)
These beautiful berries are rich in vitamin C as well as flavonoids and antioxidants. Flavonoids are meant to defend the plants. When humans eat them, they help protect cells. They also have strong antiinflammatory properties.
Add them to your morning cereal or yogurt for some natural sweetness. If you have excess on hand, freeze them and use them for smoothies.
Cherries have strong antioxidant benefits and can help protect against viruses. They contain anthocyanins and cyanidin which are helpful in reducing inflammation. Cherries also have lots of potassium which helps improve blood pressure and hydration — great for post workout.
If you’re going for cherry juice, aim for the 100% cherry juice types with no added sweeteners or sugar. Cherry juice labeled as “cocktail” typically has a lot of sugar and preservatives added.
4) Tea (green and black)
Green and black tea are packed with flavonoids, a type of antioxidant. Green tea in particular contains epigallocatechin, an antioxidant which has been shown to enhance immunity. Green tea is also rich in L-theanine. This is an amino acid (protein building block) that can improve the germ fighting action of your T-cells.
Try substituting a cup of coffee for a cup of tea every day. If you’re in a hot climate, make some home brewed iced green tea and add a bit of honey for sweetness.
Ginger is a strong anti-inflammatory which can help prevent some chronic diseases. It also has been suggested to have antibacterial benefits such as fighting against some bacteria.
This sweet tasting root makes an excellent fresh tea. Simply peel and slice it and add hot water. It’s also a perfect addition to simple dishes such as a stir-fry.
Whole garlic cloves contain allicin. This is a compound that gives garlic it’s pungent taste. It also converts to sulphur compounds which can boost white blood cell function. This makes your body better equipped to fight viruses.
It’s healthier to have the whole garlic version instead of powdered. In order to activate allicin, crush, chew, or slice the garlic cloves.
Turmeric gives curries their bright yellow color. It’s a root that’s been used for medicinal use, dating back nearly 4000 years. The active compound is called curcumin which is a very powerful antioxidant.
Curcumin content is not super high in turmeric and it’s not easily absorbed. But consuming it with black pepper and a healthy fat can help hike up the bioavailability, or how well it’s digested and absorbed by your body.
Simmering vegetables or bones in water releases immune benefiting vitamins and minerals. Bone broth can be made from cow, chicken, and even fish bones. In bone broths you also get collagen which is a protein used for your bones, muscles, and skin.
To make broth, simply boil water and add vegetables such as carrots, onions, celery, mushrooms. If you’re making bone broth, add a bit of vinegar. Boil water then let simmer for a minimum of 2 hours, then strain.
9) Red Bell Pepper
Red bell peppers have the most vitamin C of any fruit or vegetable. Due to their bright red color, they’re also a rich source of beta carotene.
Red bell peppers are fully ripe and require more time to grow. This makes them a bit more expensive but also more rich in nutrients than red and yellow ones. Red bell peppers have almost ten times more beta-carotene and vitamin A than the other colors.
Medicinal mushrooms have been a common element of Eastern medicine for ages. They recently gained popularity in Western culture. Although they aren’t necessarily a cure all, research is suggesting they can help with heart health, cancer and age related disease.
They’re also an excellent source of vitamin D which is essential for the immune system, a healthy metabolism, and mental health.
Experiment with different types of mushrooms. Some of the healthiest are reishi, lion’s mane, turkey tail, and chaga.
11) Cruciferous Vegetables (broccoli, Brussels sprouts, cabbage)
These powerful vegetables all come from the cruciferous family which are known for their cancer fighting abilities. They include broccoli, Brussels sprouts, cauliflower, cabbage, bok choy, and kale.
These amazing vegetables are packed with immune boosting vitamins such as vitamins A, C, and E. In addition they can potentially prevent DNA damage and therefore protect against certain types of cancer.
If eating these vegetables raw causes you to have gas and bloating, try steaming, sautéing or roasting them. Vinegar or lemon juice can also help break down the tough fiber of kale and cabbage for a healthy salad.
12) Leafy Greens (spinach, arugula, microgreens)
Leafy green vegetables are full of medicinal-like nutrients such as flavonoids and carotenoids. They’re also rich in vitamin C and E.
Keep them on hand whenever possible and make a quick salad or add them to your morning eggs. They’re easy to “sneak” into meals by just adding a handful here and there. Eat them with some healthy fat such as oil in order to increase absorption of the nutrients.
13) Sweet Potatoes
These are rich in beta carotene which gives them their rich orange color. Beta carotene is also a powerful antioxidant and helps produce vitamin A.
They’re very easy to roast. Or if you don’t have an oven or prefer a faster prep time, simply cut them into small chunks and boil them until soft.
These are excellent to keep on hand for extended periods of time since they’re not very perishable.
Tomatoes are an excellent source of lycopene, a type of carotene. Lycopene can help immune function and has been shown to prevent some types of cancer.
Tomatoes are also rich in vitamin C, one of the top immune boosting nutrients.
When lycopene is paired with a fat source, it boosts the absorption by almost 5 times! Drizzle oil on your salad with tomato or make your own homemade salsa and guac.
Yogurt and other fermented dairy products such as kefir are rich in probiotics. These are healthy bacteria which keep your gut healthy and stimulate your immune system. They also have a benefit on health conditions, from heart disease to arthritis to cancer. Yogurt is also rich in vitamin D.
Aim for the types without added flavor or fruit since these are most always sweetened. The sweetened versions are packed with sugar. If you don’t like the taste of plain yogurt, try adding natural sweetness by adding fruit. You can also add a bit of honey or maple syrup.
16) Nuts (almonds, walnuts, cashews)
Nuts are rich in vitamin E which acts as a powerful antioxidant. It also helps the formation of white blood cells. Nuts are also rich in heart healthy fats, which can help boost “good” cholesterol (HDL) while decreasing the “bad” cholesterol (LDL).
Nuts make excellent snacks to keep on hand to prevent yourself from getting too hungry. Aim for a small handful of nuts every day and go for the unsalted ones without added oil. Even better, roast your own. When vitamin E is heated at high temperatures in factories, it can become damaged.
17) Fatty Fish (salmon, tuna, herring)
Oily fish such as salmon, tuna, and herring are rich in omega-3 fatty acids. Omega-3 decreases inflammation and has been suggested to boost white blood cell activity.
The Dietary Guidelines of Americans recommends consuming about two to three servings of fish per week.
Want to eat your fish sustainably? Check out the Monterey Aquarium’s guide Seafood Watch.
18) Shellfish (oysters, clams, mussels, lobster, crab)
Shellfish includes oysters, clams, mussels, lobster, and crab. These are packed with zinc, protein, and healthy fats that help improve the immune system. They are also rich in selenium and B vitamins which help support brain health and immunity.
Eating just two oysters can provide the daily recommended amount of zinc. Be careful not to overdo the amount of oysters or shellfish you have because having too much zinc can cause toxicity.
19) Poultry (chicken, turkey)
Poultry such as chicken and turkey are high in B vitamins which help support a healthy metabolism, energy systems, and immunity. These are also rich in protein, which supports immunity and helps build muscle.
To save on cost and get a wide variety of nutrients, buy a whole chicken or turkey to roast. Then use the bones to make a healthy broth.
20) Seeds (chia, pumpkin, sunflower)
Seeds are rich in protein, healthy fats, and minerals such as phosphorus, magnesium, and B vitamins. They also contain vitamin E which is a powerful antioxidant.
Flax and chia seeds are rich in heart healthy omega 3. Pumpkin seeds and sunflower seeds are rich in zinc.
Add seeds to your morning cereal, yogurt, or as a topping for salads or stir-frys.
21) Beans (red, pinto, navy, black)
Beans are rich in a variety of nutrients such as B vitamins, potassium, magnesium, and fiber. Fiber is the food for healthy gut bacteria. So when you eat fibrous foods like beans, it helps build the community of healthy bacteria in your gut. A healthy gut equals a healthy body and immunity.
Aim for a variety of different colors and types. Red, pinto, navy and black beans all help boost immunity and decrease inflammation.
Immune System 101
Dr Murray is a leading naturopath doctor. In his book, Total Body Tune-Up, he explains how the immune system works, what lifestyle factors compromise it, and what nutrients boost it. Here’s a summary:
Your body is built to protect you from disease. Your skin is one of the first lines of defense which is one reason why adequate hydration is important. Your mouth, nose, and eyes are openings where invaders can attack. This is why your body produces mucus and why you sneeze and cough when you get sick — to reinforce the barrier and get the germs out.
Your bones contain marrow which produce red blood cells and most of the white blood cells. The red ones are involved with oxygen transport, necessary for breathing and energy. The white blood cells are known as immunity cells. They fight viruses, bacteria and other foreign invaders.
The thymus, which is a butterfly-shaped gland located at the base of your neck, will help those white blood cells mature.
People with low thymus function are prone to infection. The thymus gland matures white blood cells as well as produces hormones that regulate many immune functions.
The thymus naturally gets smaller with age. But certain external factors including free radicals (unstable molecules that can damage the cells in your body) from poor diet, disease, stress, or exposure to environmental toxins, can cause thymus tissue to shrink faster and lower immunity.
To support your thymus, it’s important to eat a diet rich in antioxidants such as beta-carotene, vitamins C, E, selenium, and zinc. More on these powerful nutrients in a bit!
Your lymphatic system is a network of vessels that collect fluid found between your cells. It passes through the lymph nodes, which filter impurities such as bacteria.
Inside your lymph nodes are white blood cells which engulf and destroy the impurities. This is why your lymph nodes get swollen when you’re fighting a disease.
In order to keep your lymph healthy, it’s crucial to keep it circulating. This is dependent on your breathing and movement — contracting muscles and inhaling.
Muscular contractions pump lymph out of the arms and legs into the larger lymph vessels. Inhaling expands the diaphragm which puts pressure on the lymphatic vessels in the abdomen and chest.
In other words, exercise and deep breathing help immunity.
Just keep in mind that doing excessive intense exercise (like HIIT), too often, can stress your body and weaken your immunity. Learn more here:
In addition to breath and movement, key players in immunity are stress management and nutritional support.
Nutrition and Immunity
“A deficiency of virtually any single nutrient can significantly impair immunity.” – Dr. Murray.
In order to boost your immunity, you need to cut out or limit the stuff that depletes it (alcohol, sugar, and processed foods) while increasing nutrients that support the immune system (vitamin C, vitamin D, vitamin A, B vitamins, vitamin E, carotenes, selenium, zinc, protein).
REDUCE OR AVOID:
Alcohol can negatively disrupt your immune pathways, impairing your body’s ability to defend against infection, contributing to organ damage, and blocking recovery from tissue injury.
Moderation counts as up to one drink a day for women and up to two drinks a day for men.
One drink equals:
Beer: 12 fluid ounces (355 millimeters)
Wine: 5 fluid ounces (148 millimeters)
Spirits: (80 proof): 1.5 fluid ounces (44 millimeters)
Eating too much sugar overtime can lead to inflammation, increasing the chance of getting sick from colds or viral infections. Excessive sugar has also been suggested to increase the risk of obesity, type 2 diabetes, and heart disease (which all can depress your immune system).
Studies presented in Total Body Tune-Up, found that eating 100g of sugar reduces the effectiveness of a white blood cell called a neutrophil by 40% within two hours. Neutrophils engulf and destroy bacteria.
According to the American Heart Association, try not to eat more than:
Men: 150 calories per day (37.5 grams or 9 teaspoons)
Women: 100 calories per day (25 grams or 6 teaspoons)
According to Today’s Dietitian, the typical American diet has been associated with a number of health risks including heart disease, type 2 diabetes, and obesity — all of which can lead to decreased immune function.
This diet focuses on highly processed foods which are high in saturated and trans fat, sodium, and refined sugar while having less nutrients such as omega-3, fiber, and phytochemicals.
This way of eating can reduce white blood cell phagocytosis (a cell engulfing an invader). Saturated fat is also noted to be inflammatory. Processed foods can also compromise the microbiome (healthy bacterial balance).
Focus on a diverse diet with lots of fresh vegetables and fruits, whole grains, beans, nuts and seeds. Plant foods are loaded with nutrients. If you’re not able to access fresh produce, try some non-perishable alternatives.
Keep in mind that when it comes to nutrients in the form of supplements, more isn’t necessarily better. When nutrients are extracted from their original sources, such as in the case of creatine supplements, they are often not as beneficial as the original source and can make it too easy to overdo it.
Rightfully one of the most popular nutrients related to immune function. Vitamin C “turns on” white blood cells in order to get them ready to attack foreign intruders. It also boosts interferon levels (substance that interferes with the ability of viruses to reproduce), antibody levels, and hormones from the thymus.
Vitamin C acts against viruses. When you have an infection, are under stress, or if you’re a smoker, your vitamin C needs increase.
Vitamin D is manufactured by our bodies with access to sunshine. Immune cells, including B cells, T cells, and antigen are capable of synthesizing and responding to vitamin D.
Studies have even suggested that vitamin D deficiency is associated with increased autoimmunity (immune system mistakenly attacks the body’s own tissues or organs) as well as increased risk of getting an infection.
Vitamin A helps maintain healthy cells of the skin and mucous membranes which are the first lines of defense against infection. It’s also essential for white blood cell function. It can boost thymus function and antibody response.
It’s an anti-inflammatory vitamin. Research suggests that vitamin A has therapeutic effects in the treatment of various infectious diseases.
B vitamins, especially B1, B6, and B12, are required to make antibodies that fight disease. When levels are low, it prevents your body from making white blood cells. Lymphoid tissue also decreases when there’s not enough B vitamins.
Studies show that B vitamins have significant participation in the production of circulating antibodies and antigens which help stop intruders from harming the body.
Vitamin E supports immunity by encouraging the formation of white blood cells and antibodies. It’s a fat soluble (absorbed with fat) antioxidant which fights damage from environmental wear and tear.
Research shows that vitamin E can help decrease the incidence of tumors. Vitamin E plays an important role in the T cells in the thymus, helping them mature.
Carotenes are the orange, yellow, and red pigments found in fruits and vegetables. They are effective antioxidants which protect against damage thought to lead to cancer.
They help protect your thymus gland because of their antioxidant benefits. Beta carotene is a precursor of vitamin A, meaning your body needs it in order to make vitamin A.
Selenium is involved in important antioxidant mechanisms in your body. People who are low in selenium have lower antibody levels.
The Journal of Nutrition explains that selenium has a very strong impact on the immune system. It acts as an antioxidant and helps protect white blood cells from free radical damage.
One study found that people who took supplements with 200 mcg of selenium per day showed almost a doubling in the activity of white blood cells.
The typical American diet doesn’t contain enough selenium. And research is showing that the amount of selenium is low in plants due to decreasing soil quality.
When zinc is low, the number or T cells decrease, thymus hormone levels decrease, and certain white cell functions don’t work. Zinc also helps other nutrients be absorbed in your digestive system.
Studies have shown that zinc has antioxidant and antiinflammatory benefits. In a double-blind clinical trial, participants who took lozenges containing zinc significantly reduced their common cold duration.
After seven days of taking the lozenges, 86% of the patients were symptom-free compared to only 46% who took a placebo.
In order to be effective, the lozenges have to be free of sorbitol, mannitol and citric acid. This is because these compounds bind with zinc and reduce their effectiveness. So check your labels before buying!
Protein often gets overlooked when it comes to focusing on the immune system. It’s one of the most important factors when it comes to making white blood cells, antibodies, and chemical messengers.
Protein is also needed in order to make enzymes such as glutathione. Glutathione is one of the body’s strongest antioxidants. Elevated glutathione levels are associated with better immune function.
The Academy of Nutrition and Dietetics states that protein is a key immune nutrient due to its role in the immune system and ability to help heal and recover.
Following two simple lifestyle shifts can go a long way in keeping your immune system strong for the long haul.
The first goal is to consistently incorporate the above superfoods while minimizing alcohol, sugar, and processed food intake.
Next is to follow a healthy lifestyle which includes deep breathing, adequate sleep and rest, and moderate exercise.
By advocating for your health, you’ll not only up your resistance to colds, flus, and other infections, you’ll also protect yourself against potentially deadly disease.
Wishing you health and happiness.
About The Author
Lisa is a registered dietitian nutritionist (RDN) with over 15 years of experience in nutrition, fitness, and mental health coaching and education. She studied Foods and Nutrition at San Diego State University and earned a Master of Science in Holistic Nutrition at Hawthorn University.
Having certifications and experience in group exercise, intuitive eating, coaching and psychotherapy, and digestive wellness, she’s enthusiastic about the relationship between the body and mind.
She’s dedicated to helping people understand how to implement healthy habit change, while gaining a deeper understanding of what makes them feel their personal best.