Your immune system is the first line of defense against harmful pathogens that can cause acute and chronic illness. It is an extensive network of organs, cells, and proteins that work together to protect the body from viruses, bacteria, fungi, and other germs. And, if an invader enters the body and causes harm, the immune system is responsible for healing that damage and adapting to future threats.
There are many ways to support a healthy immune system, including regular physical activity and good sleep hygiene. However, diet (with an emphasis on certain nutrients) also plays an important role.
Here are the best foods for immune system health, and the science behind them.
1. Citrus Fruits
Citrus fruits are known for their vitamin C content and are often praised for their role in supporting immune function. Vitamin C, or ascorbic acid, is a water-soluble vitamin that is essential for tissue growth and repair. As an antioxidant, vitamin C fights free radicals and helps prevent certain cancers, heart disease, and other chronic health problems.
Adults need an average of 75 to 90 milligrams (mg) of vitamin C per day. However, the body cannot produce vitamin C, so it must be consumed through the diet.
Examples of citrus fruits and their vitamin C content include:
- Oranges:82.7 mg of vitamin C per fruit
- Tangerines:32 mg of vitamin C per fruit
- Limes:19.5 mg of vitamin C per fruit
- Grapefruit:39.3 mg of vitamin C per 1/2 fruit
Citrus fruits can be enjoyed fresh or as an ingredient in a variety of dishes. Adding juicing can enhance the flavor and vitamin C content of many classic recipes.
2. Red Bell Peppers
Bell peppers, especially red bell peppers, can also support a healthy immune system. Surprisingly, red bell peppers contain more vitamin C than most citrus fruits. One large red bell pepper contains 210 mg of vitamin C, which is more than double the recommended daily intake.
However, the benefits of bell peppers don’t stop there. They contain β-carotene, a powerful antioxidant that gives peppers their rich red color and fights free radicals. β-carotene is also known for its provitamin A activity, which means bell peppers can also support eye and skin health.
Bell peppers add a delicious and enticing texture to many snacks and meals. Enjoy them fresh as a delicious, crunchy snack, or cook them and add them to a variety of meals. Bell peppers are great for stir-fries, wraps, and pasta.
3. Yogurt
Research continues to show a link between gut health and overall health. The gastrointestinal tract is home to a complex microbial community that supports your health through its energy-regulating and immune response effects. However, not all bacteria are beneficial for gut health, so it’s important to prioritize the good bacteria that are present.
Eating probiotic-rich foods like yogurt can increase the number of beneficial bacteria in your gut microbiome. Greek yogurt is especially beneficial for the immune system because it provides high-quality protein and helps diversify intestinal flora.
Yogurt can be enjoyed on its own or as a base for a nutritious parfait. For example, mix a serving of yogurt with a mixture of berries and granola to increase your intake of vitamin C and fiber. Yogurt can also provide a nutritional supplement to many soups, smoothies, and dressing recipes.
4. Fatty Fish
Most cells in the immune system have vitamin D receptors, suggesting that vitamins are directly related to a properly functioning immune system. Fatty fish such as salmon and mackerel are rich in vitamin D. For example,3 ounces (oz) of cooked salmon provides 14.5 micrograms (mcg) of vitamin D, which is 97% of the recommended daily intake.
In addition, fatty fish are an excellent source of omega-3 fatty acids, which have been linked to reduced mortality from major causes such as cardiovascular disease, cancer, and Alzheimer’s disease. Studies have demonstrated a link between omega-3 fatty acids and reduced expression of pro-inflammatory markers. Still, when eating fatty fish, be sure to pay attention to portion sizes, as eating too much of it, even if it’s healthy fat, can have adverse results.
5. Poultry
Poultry cuts such as chicken breast and turkey breast are rich in vitamin B6, which can support a healthy immune system. Vitamin B6 is essential for the production of T lymphocytes and interleukin, which are important for the immune system to function optimally. In addition, studies have shown a link between vitamin B6 deficiency and chronic inflammation, suggesting that vitamins can reduce oxidative stress.
A 4-ounce serving of chicken breast provides 0.916 mg of vitamin B6, which is 54% of the maximum recommended daily intake. You can enjoy grilled, smoked, or grilled poultry meats, and you can also pair them with a variety of fresh, natural foods to maximize the benefits of their immune system. For example, grilled chicken is chopped and mixed with a variety of vegetables to make a delicious protein-rich salad.
6. Green Leafy Vegetables
Leafy greens, such as spinach, kale, and Swiss chard, can affect a healthy immune system. They are packed with nutrients and fiber, support a healthy gut and meet many of the nutritional needs of the day. However, their antioxidant content may have the most effective effect on immunity. Studies have shown that regular consumption of leafy greens can reduce oxidative damage and inflammation in the body.
Leafy greens can be enjoyed fresh and paired with fruits, vegetables, and lean proteins to make a nutritious salad. Alternatively, they can be cooked and added to many different warm recipes. However, studies have shown that leafy greens retain their most potent antioxidants when steamed.
7. Nuts
Zinc is essential for a healthy immune system because it plays a role in regulating the system’s intracellular signaling pathways. Many foods are rich in zinc, but few are as convenient as nuts. Nuts such as cashews, almonds, and pine nuts are excellent sources of zinc. For example,1 ounce of cashews provides 1.64 mg of zinc, which is 15% of the maximum recommended daily intake. Similarly,1 ounce of almonds provides 0.885 mg of zinc or 8% of the upper limit of the recommended range.
Nuts are a convenient on-the-go snack that can also be added to a variety of dishes. Add them to hot or cold cereal foods for added nutrition and extra crunchiness, or mix them into grain-based side dishes with dinner.
8. Ginger
Ginger is a flowering root plant from Southeast Asia that has a positive effect on the immune system. It has antioxidant and anti-inflammatory properties, suggesting that it can help reduce the risk of chronic health problems such as cardiovascular disease. Studies have shown that ginger can block pro-inflammatory cytokines and inhibit oxidative molecules that cause inflammation in the body.
It’s easy to add ginger to a balanced diet. Peeled fresh ginger can be shredded, diced, or sliced and used in a variety of recipes. It is also available in the form of dried ginger, powder, or oil, but processed ginger may not provide the same powerful benefits as fresh ginger.
9. Turmeric
Turmeric is a bright yellow bitter spice that contains a bioactive compound called curcumin. Curcumin works synergistically with cells in the immune system, such as macrophages and natural killer cells, to boost the body’s defenses. Its gastric protective, anti-inflammatory, and antioxidant properties inhibit metabolic pathways that trigger inflammation and oxidative stress in the body.
Turmeric has an earthy flavor with a hint of sweetness that adds a very unique flavor to the recipe. It is often used in curry dishes, but the benefits of turmeric are endless. For example, it can be added to soups, stews, smoothies, oatmeal, marinades, and teas.
10. Garlic
Garlic has long been used for medicinal purposes because it contains a variety of compounds that have been implicated in immune function. These bioactive compounds contribute to various biological processes in the body through their antibacterial, anti-inflammatory, antioxidant, and neuroprotective properties. For example, garlic can support brain, gut, and heart health. Additionally, studies have shown that garlic can boost the immune response and reduce inflammation.
Garlic can add flavor to many delicious recipes. Consider adding it to pasta sauces, mashed potatoes, stir-fries, dressings, and dips.
Other Ways to Boost Immunity
Nutrition plays a vital role in maintaining a healthy immune system. However, maximizing immune function requires a holistic approach that includes:
Sleep: Sleep is essential for immunity as it is an opportunity for the body to recharge and replace important infection-fighting cells. Sleep deprivation is associated with an increased risk of chronic inflammation and infection. Adults should get at least 7 hours of sleep each night to optimize immune health.
Regular physical activity: Physical activity supports a healthy immune system in a variety of ways. Regular physical activity can help reduce anxiety, support weight management, and improve sleep patterns. The latest physical activity guidelines for Americans recommend 150 minutes of moderate-intensity exercise per week.
Stress management: While research needs to continue, current research suggests that elevated stress levels may be related to immune system dysregulation. Stress is a broad concept that can vary from person to person. However, management techniques such as yoga, meditation, and healing can help alleviate symptoms of stress.
Summary
The immune system is a complex network of organs, cells, and proteins that work together to keep you healthy. But in order for it to reach its maximum potential, it’s important to nourish your immune system through a balanced diet rich in zinc, omega-3 fatty acids, and vitamins A, B6, C, and D.
Foods like citrus fruits and red bell peppers are rich in vitamin C, while fatty fish are excellent sources of omega-3 fatty acids. Poultry is a good source of vitamin B6, and many nut varieties are rich in zinc.
Additionally, yogurt and other fermented foods that contain probiotics can help support a healthy gut. A balanced gut microbiome is essential for overall health, as it plays a vital role in many immune pathways.
In addition to eating a balanced diet, getting enough sleep, managing stress levels, and incorporating regular physical activity into your lifestyle are important. Aim for at least 7 hours of sleep per night and at least 150 minutes of moderate-intensity exercise per week.
