10 July 2018 By Lana Burgess Reviewed by Katherine Marengo LDN, RD
Medical News Today

A strong immune system helps to keep a person healthy. Can specific foods boost the immune system?

The immune system consists of organs, cells, tissues, and proteins. Together, these carry out bodily processes that fight off pathogens, which are the viruses, bacteria, and foreign bodies that cause infection or disease.

When the immune system comes into contact with a pathogen, it triggers an immune response. The immune system releases antibodies, which attach to antigens on the pathogens and kill them.

Incorporating specific foods into the diet may strengthen a person's immune response. Read on to discover 15 foods that boost the immune system.

Which foods boost the immune system?
A healthful, balanced diet plays a vital role in staying well. The following foods may help to boost the immune system:

1. Blueberries
Blueberries have antioxidant properties that may boost the immune system.
Blueberries contain a type of flavonoid called anthocyanin, which has antioxidant properties that can help boost a person's immune system. A 2016 study noted that flavonoids play an essential role in the respiratory tract's immune defense system.

Researchers found that people who ate foods rich in flavonoids were less likely to get an upper respiratory tract infection, or common cold, than those who did not.

2. Dark chocolate
Dark chocolate contains an antioxidant called theobromine, which may help to boost the immune system by protecting the body's cells from free radicals.

Free radicals are molecules that the body produces when it breaks down food or comes into contact with pollutants. Free radicals can damage the body's cells and may contribute to disease.

Despite its potential benefits, dark chocolate is high in calories and saturated fat, so it is important to eat it in moderation.


3. Turmeric
Turmeric is a yellow spice that many people use in cooking. It is also present in some alternative medicines. Consuming turmeric may improve a person's immune response. This is due to the qualities of curcumin, a compound in turmeric.

According to a 2017 review, curcumin has antioxidant and anti-inflammatory effects.

4. Oily fish
Salmon, tuna, pilchards, and other oily fish are a rich source of omega-3 fatty acids.

According to a 2014 report, long-term intake of omega-3 fatty acids may reduce the risk of rheumatoid arthritis (RA).

RA is a chronic autoimmune condition that occurs when the immune system mistakenly attacks a healthy part of the body.

5. Broccoli
Broccoli is another source of vitamin C. It also contains potent antioxidants, such as sulforaphane. For these reasons, it is a good choice of vegetable to eat regularly to support immune system health.

6. Sweet potatoes
Sweet potatoes are rich in beta carotene, a type of antioxidant that gives the skin of the potatoes its orange color.

Beta carotene is a source of vitamin A. It helps to make skin healthy and may even provide some protection against skin damage from ultraviolet (UV) rays.

7. Spinach
Spinach may boost the immune system, as it contains many essential nutrients and antioxidants, including:

flavonoids
carotenoids
vitamin C
vitamin E
Vitamins C and E can help support the immune system.

Research also indicates that flavonoids may help to prevent the common cold in otherwise healthy people.


8. Ginger
People use ginger in a variety of dishes and desserts, as well as in teas.

According to a review, ginger has anti-inflammatory and antioxidative properties and is likely to offer health benefits. However, more research is necessary to confirm whether or not it can effectively prevent illness.

9. Garlic

Garlic may help to prevent colds.
Garlic is a common home remedy for the prevention of colds and other illness.

One review looked at whether taking garlic supplements containing allicin reduced the risk of getting a cold.

The group of participants taking a placebo had more than double the number of colds between them than those taking the garlic supplements. However, the researchers concluded that more research is necessary to determine whether or not garlic can help to prevent colds.

10. Green tea
Green tea contains only a small amount of caffeine, so people can enjoy it as an alternative to black tea or coffee. Drinking it may also strengthen the immune system.

As with blueberries, green tea contains flavonoids, which may reduce the risk of a cold.

11. Kefir
Kefir is a fermented drink that contains live cultures of bacteria that are beneficial for health.

Initial research suggests that drinking kefir may boost the immune system. According to a 2017 review, various studies have shown that regular consumption of kefir can help with:

fighting bacteria
reducing inflammation
increasing antioxidant activity
The majority of the research that supports this was carried out on animals or in a laboratory. Researchers need to perform additional studies to understand how kefir may prevent disease in humans.

12. Sunflower seeds
Sunflower seeds can make a tasty addition to salads or breakfast bowls. They are a rich source of vitamin E, an antioxidant.

In the same way as other antioxidants, vitamin E improves immune function. It does this by fighting off free radicals, which can damage cells.


13. Almonds
Almonds are another excellent source of vitamin E. They also contain manganese, magnesium, and fiber.

A small handful or a quarter of a cup of almonds is a healthful snack that may benefit the immune system.

14. Oranges or kiwifruit (kiwis)
Oranges and kiwis are an excellent source of vitamin C, which is the vitamin that many people turn to when they feel a cold developing.

While scientists are still not sure exactly how it helps, vitamin C may reduce the duration of common cold symptoms and improve the function of the human immune system.

15. Red bell pepper
For people trying to avoid the sugar in fruit, red bell peppers are an excellent alternative source of vitamin C.

Stir-frying and roasting both preserve the nutrient content of red bell peppers better than steaming or boiling, according to a study on cooking methods.

Other ways to boost the immune system
Washing hands properly may help make the immune system stronger.
Washing hands properly may help make the immune system stronger.
The following lifestyle strategies may make a person's immune system stronger:

avoiding smoking
exercising regularly
maintaining a healthy weight
avoiding alcohol or drinking in moderation
getting enough sleep
minimizing stress
practicing correct hand-washing and oral hygiene


Enjoying the 15 immune-boosting foods covered in this article may strengthen people's immune system and improve their ability to fight off infections.

That said, it is important to remember that the immune system is complex. Eating a healthful, balanced diet is just one way to support immune health.

It is also essential to be mindful of the other lifestyle factors that may affect immune system health, such as exercising and not smoking.

Anyone who gets frequent colds or other illnesses and is concerned about their immune system should speak to a doctor.