Boosting Immunity: Foods to Fight the Common Cold

Written by: Natalie Pirolli, MS, RDN, LDN, RYT | October 22, 2024

As the leaves start to change color and the air becomes more crisp, it is a beautiful time of year to catch a nasty cold. It's like we pull out our comfy sweaters and make plans to enjoy the great outdoors and BAM—those perpetual sniffles have suddenly turned into a head-throbbing cold. With the change of season, back-to-school germs, and increase in social events, this time of year can certainly make us more susceptible to sickness. While there’s no magic potion to completely dodge the common cold, we can give our immune system a serious boost with the right foods.

Nutrition plays a key role in our immune system functioning. From the development of immune cells to reducing inflammation and boosting gut health, the power of food is undeniable. Let’s dive into some powerful nutrients and tasty foods that can help keep us feeling our best.

Key Nutrients for Immune Health

Vitamins and minerals are essential for proper functioning of many body processes. Here we'll focus on a few immune-specific benefits of some key vitamins.

Vitamin A

Vitamin A plays a vital role in the development of immune cells and maintenance of mucosal barriers, which are our first line of defense against pathogens. It also helps reduce inflammation, which can weaken our immune response, by acting as an antioxidant. 

We can find vitamin A in orange produce like sweet potatoes, butternut squash, and carrots, and animal products like beef liver, eggs, and dairy.

Vitamin C 

One of the most well-known vitamins for immune support, vitamin C plays a critical role in the production of white blood cells, which are essential for fighting infections. Studies show that adequate vitamin C intake can reduce both the duration and severity of colds. 

We can find vitamin C in citrus fruits like oranges and grapefruits, strawberries, bell peppers, potatoes, and broccoli.

Vitamin D 

Vitamin D is crucial for immune function. It helps modulate the immune response and has been shown to reduce the risk of respiratory infections. Often referred to as the "sunshine vitamin", we can increase our levels by spending time outdoors, exposing our skin to the sun. When sunlight is harder to come by we can boost our intake of vitamin D through food and supplementation if needed.

We can find vitamin D in foods like fatty fish (such as salmon and mackerel), fortified dairy products, and egg yolks. 

Zinc

This mineral is key for developing and activating immune cells. If you’re not getting enough zinc, you might find yourself catching colds more easily. 

We can find zinc in oysters, red meat, poultry, beans, nuts, pumpkin seeds, and whole grains.

Probiotics

Did you know your gut health plays a big role in your immune health? Probiotics (beneficial bacteria found in fermented foods) can both enhance the gut microbiome and boost the immune response. Prebiotics are fibrous foods that serve as food for probiotics to thrive. Eating a variety of fruits, vegetables, and whole grains is one way we can promote a healthy gut.

We can find probiotics in yogurt, kefir, sauerkraut, kimchi, olives, and fermented pickles. Prebiotics include bananas, onions, leeks, asparagus, artichokes, and ground flaxseeds.

Antioxidants 

These little warriors protect our bodies from oxidative stress, which can weaken the immune system. Vitamins A, C, and E serve as powerful antioxidants that help support immune function. Phytonutrients (what gives plants their color) also have antioxidant properties, which is one of the reasons why it can be beneficial to have a variety of colors in the diet. 

We can find antioxidants in colorful fruits and vegetables, nuts, seeds, and whole grains.

Key Foods for Immunity

Eating enough to meet our nutrient and energy needs is an important first step for our overall well-being. This list highlights some of the more well-known foods linked to immune health and is by no means exhaustive (as many foods benefit our health!).

Berries

Berries, especially blueberries, are rich in antioxidants that support our immune health and a great source of vitamin C. Frozen produce is picked at peak ripeness, making frozen berries a great choice for when you want them to last a while longer, and when they're out of season.

How to enjoy: add them to smoothies, yogurt, or oatmeal for a nutrient-dense snack.
Frozen wild blueberries are tiny, so they thaw quickly in oats and add a nice little crunch to yogurt!

Bone Broth & Chicken Broth

Bone broth is rich in nutrients like amino acids, minerals, and collagen, which can support gut health and immune function. Warm bone broth can be a soothing remedy when you're feeling under the weather and add an extra boost of protein to your meal (about 9g per cup!). Chicken broth is equally as soothing but not as rich in protein. Both bone and chicken broth contain the amino acid cysteine, which can help to loosen and thin mucus secretions.

How to enjoy: add to your homemade soups, use in place of water when making rice or quinoa, or sip on a warm mug with an added pinch of salt.

Citrus Fruits

Citrus fruits are high in vitamin C and a good source of copper, both of which help us absorb iron. Iron also plays a role in immunity and a deficiency can weaken the immune system. Think oranges, lemons, limes, kiwi, grapefruit, and clementines.

How to enjoy: clementines make an easy on-the-go snack and lemon juice can be added to water for taste and digestion support. Limes are also great in adrenal cocktails mixed with coconut water!

Cruciferous Veggies

Veggies like broccoli, Brussels sprouts, cauliflower, arugula, and curly kale are rich in nutrients like vitamin C and contain glucosinolates, a sulfur-rich compound that aids liver detoxification. In addition to helping our body rid toxins, these foods also possess antioxidants and anti-inflammatory effects.

How to enjoy: roast a batch of broccoli and enjoy chopped with cheddar in an omelet, in a pasta dish with parmesan and protein, as a dinner side, or a salad topper.

Garlic

Not only does garlic add a delicious taste to meals, it has antimicrobial properties and is known to boost immune function. In fact, garlic is one of the oldest medicinal foods and often referred to as a "natural penicillin". Garlic contains allicin, a compound that gives garlic its unique scent and helps fight off infections. To activate allicin, garlic must be smashed before consumption.

How to enjoy: roast garlic and enjoy on toasted bread with olive oil for an app or as part of meal. Sauté garlic with your veggies or you could try a raw (smashed) small clove to open your sinuses (a drizzle of honey on top can help with this!)

Ginger

Ginger is considered the "universal remedy" in Ayurvedic medicine as it is known for improving nausea, digestion, cholesterol levels, and circulation, among other things. It also has anti-inflammatory and antimicrobial properties, which can help alleviate symptoms of colds and flu. Ginger may also boost the immune system by enhancing the activity of immune cells.

How to enjoy: this spicy root adds a nice warming effect and can be grated and used fresh in teas, soups, or stir-fries.


Green Tea

Green tea is packed with antioxidants, particularly catechins, which have been shown to enhance immune function. Matcha is a form of green tea where the whole tea leaves are consumed; the tea leaves are ground to a fine powder and blended into hot water or milk. This differs from traditional or dried-leaf green tea where the leaves are steeped in water and then discarded.

How to enjoy: try dried leaf tea as is or with the addition of lemon (vitamin C!) and honey. Enjoy matcha as a latte with milk and dash of maple syrup for flavor.

Honey

Honey has been shown to have antimicrobial, antiviral, and anti-inflammatory effects. It's thought to help the immune system by stimulating antibody production. Honey can also provide relief for a sore throat and when bought locally, may help reduce allergy symptoms over time through pollen exposure.

How to enjoy: add to hot tea or hot water with lemon, use in your homemade marinades or salad dressings, drizzle on top of oatmeal or nut butter toasts.

Root Veggies

Sweet potatoes, carrots, parsnips, and beets provide beta carotene, a compound that gets converted to vitamin A (retinol) in the body. Both beta carotene and vitamin A are antioxidants. White potatoes are also a great source of vitamin C and potassium, which has antimicrobial and immune-boosting effects.

How to enjoy: roast a batch of sweet potatoes and enjoy on the side of breakfast eggs or dinner, toss in your grain bowls or onto a salad, or toast and top with nut butter and cinnamon.

Spinach

Leafy greens like spinach are loaded with vitamins A, C, and E, along with antioxidants. Kale, Swiss chard, and collard greens are some other nutritious leafy options.

How to enjoy: fresh or frozen, you can add spinach to smoothies without adding a strong taste. Frozen spinach can quickly be defrosted and added to pasta and grain dishes too.

Thyme

This herb has been used as a respiratory remedy since the Middle Ages. Thyme has antioxidant, anti-inflammatory, and antimicrobial effects.

How to enjoy: sprinkle fresh or dried onto your roasted veggies and poultry dishes, or enjoy as a cup of tea.

Turmeric

Turmeric contains curcumin, which has potent anti-inflammatory and antioxidant properties. Adding turmeric to your cooking can provide immune support, along with a warming taste and deep yellow hue. (This yellow hue can stain your wooden cooking utensils and fingernails so wash quickly--just FYI!).

How to enjoy: try a golden milk latte, use to season roasted veggies, grain bowls, tofu or egg scrambles, and soups and stews.
Tip: be sure to add a dash of black pepper as this helps us absorb curcumin!

Maintaining a strong immune system is essential, especially during cold and flu season. By incorporating nutrient-rich foods and supplements into our diet, we can bolster our defenses against illness. While nutrition plays a pivotal role in immune health, it is not the only contender. Stress management, quality sleep, and adequate physical activity are invaluable for our physical and mental well-being as well!

Consult with a healthcare professional or a registered dietitian before making significant dietary changes, especially if you have underlying health conditions.

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References:

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