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Your Ultimate Guide to Foods That Boost the Immune System

An image of immune boosting foods arranged on a wood tableIt’s important that you give your body everything it needs to be strong and healthy. This is the best way to protect yourself against COVID-19 and the threat it poses. One of the easiest ways to do this is by eating foods that boost the immune system. Ensuring that your immune system is strong is vital for your body’s defenses against this virus and everything else the world can throw at it.

What is the Immune System?

Your immune system helps to keep your body safe from infections, viruses, bacteria, and other intruders. It’s a complicated system that’s made up of cells, tissues, organs, and proteins throughout your body. Together, the different parts of the system work to fight off pathogens. When your immune system senses a threat, it triggers an immune response. Antibodies are then released to destroy the invader.

Unfortunately, not everyone’s immune system is the same. Some people have weaker immune systems. If you have a weak immune system, you’re more likely to get sick when exposed to a pathogen or virus. And when you get sick, you probably get sicker than other people.

Eating a healthy diet will help as it ensures that your body gets all the nutrients it needs to function at its best. But there are also specific foods that boost the immune system that will help directly to boost your immune function.

Lifestyle Changes to Support the Immune System

There are steps you can take to boost your health and your immune system while you’re still relatively healthy. This includes making some important lifestyle changes such as:

  • Quit smoking
  • Limit your alcohol intake
  • Sleep more
  • Exercise regularly
  • Reduce stress
  • Maintain a healthy weight

Common Foods that Boost the Immune System

There are also specific foods that boost the immune system you should be eating regularly. These include:

Nuts and Seeds

Nuts and seeds contain zinc, vitamin E, and plant-based proteins. The zinc and protein help keep your immune system functioning and vitamin E is a natural antioxidant, which neutralizes free radicals. Some of the best nuts and seeds to eat include:

  • Almonds
  • Hazelnuts
  • Walnuts
  • Sunflower seeds
  • Peanut butter

Green Tea

Green tea contains flavonoids, which may reduce the risk of catching a cold.

Probiotics and Prebiotics

The health of your gut is closely linked to the health and functioning of your immune system. That’s why some of the best foods that boost the immune system contain probiotics or prebiotics.

Prebiotics nourish good gut bacteria and are found in onions, chicory, and Jerusalem artichokes. Probiotics are live microorganisms that also help with the bacterial balance of your gut. You can get probiotics from foods like kimchi, kefir, bio yogurt, miso, fermented milk, and kombucha.


An image of someone handpicking blueberries into a basketBerries are one of the best foods that boost the immune system. They have a high polyphenol content, an antioxidant that gives them their bright colors and can help counter cell damage. They can also interact with your gut to reduce inflammation and improve immune response.

Blueberries are particularly good for improving your immune response as they also contain a flavonoid called anthocyanin. This has antioxidant properties that can boost the immune system. And flavonoids are especially good for the immune system of your respiratory tract, which may help with your body’s defenses against viruses.


Vegetables contain lots of nutrients that your body needs to function properly. However, green and orange vegetables are particularly important when you’re looking for foods that boost the immune system. Vegetables contain beta-carotene, which is converted to vitamin A and plays a vital role in immune system development and regulation.

Vitamin A also helps protect the skin. It protects the integrity of tissues that cover the body’s organs and the membranes that lines the nose, mouth, bladder, and lungs as well. This is important because of the skin, tissue, and mucus act as a barrier against external invaders like viruses.

Some particularly good vegetables for your immune system are:

  • Sweet potatoes
  • Broccoli, which is also a good source of vitamin C and contains powerful antioxidants.
  • Carrots
  • Peppers, especially red peppers which also contain lots of vitamin C.
  • Spinach, which contains lots of immune-boosting substances like flavonoids, vitamins C and E, and carotenoids.

Oily Fish

Oily fish like tuna, salmon, and pilchards contain omega-3 fatty acids, which may help calm the immune system. It’s often used to reduce the risk of rheumatoid arthritis (RA), which occurs when your immune system attacks your joint tissues.


Certain fruits, like kiwi and oranges, contain a lot of vitamin C, which is often used to prevent colds or lessen their duration and may improve immune system function.

You should also be eating lots of citrus fruits, which contain polyphenols. These substances can prevent cell damage and boost the immune system. Citrus fruits are also a good source of vitamin C, which may boost your immune system. Some of the best citrus fruits to eat include oranges, lemons, and limes.


Turmeric contains curcumin, which has antioxidant and anti-inflammatory effects.


Studies have shown that ginger may have anti-inflammatory and anti-oxidative properties, which can help with good immune system function.


Garlic is one of the most popular foods that boost the immune system and is often used to prevent colds and illnesses. More research is needed, but there is some evidence that this may help boost immune function.

The Immune System and Adrenal Fatigue

An image of a doctor putting a white card with cortisol written on it into his pocketStress can be incredibly damaging to your body. Everyone has a different tolerance level for stress, usually dictated by the NeuroEndoMetabolic (NEM) stress response, which makes changes throughout your body’s circuits in response to stress. Unfortunately, chronic stress means that this stress response is often overactive in the modern world. And this can cause imbalances in the circuits, which can't return to their pre-stress functioning level and can start to degrade in health.

Often, the first sign of adrenal fatigue is found in the adrenal glands. These are the primary driver of the NEM stress response as they release cortisol, the hormone that prepares you to fight or flee during times of stress. Cortisol ‘wakes up’ your body, preparing it to face a threat. But if the cause of the stress isn’t alleviated, your body will continue to demand high levels of cortisol over a long period. This can cause imbalances and malfunctions throughout your body, including in the adrenal glands. The adrenals can start to struggle with their functions, resulting in Adrenal Fatigue Syndrome (AFS) and a host of stressful, damaging symptoms and problems.

When your body is flooded with cortisol like this your immune system will activate. This prepares your body to respond to a threat quickly and decisively. But if cortisol levels don’t ease, then the constant overactivity can start to unbalance the immune system and the Inflammation Circuit. And this can be catastrophic for your overall health and your immune response.

Inflammation Circuit Imbalances and Foods that Boost the Immune System

Inflammation Circuit Imbalances are very common in AFS. This circuit includes the immune system, the gut, and the microbiome or bacterial balance. These three components work together to produce inflammation in response to a threat to the body. This inflammation is designed to expel the threat and is a natural, essential part of the healing process.

But when you have AFS, too much inflammation can become quite damaging. People with AFS often experience chronic inflammation because of imbalances in the Inflammation Circuit and additional problems and symptoms caused by AFS.

Chronic inflammation can cause your immune system to start attacking your cells or tissues, resulting in new allergies or sensitivities. It can also unbalance the microbiome, causing ongoing infections that further tax your health. This negatively affects the health of your gut, causing food sensitivities, and also the digestive and excretory problems. This, in turn, will cause more inflammation and worsen the underlying imbalance.

If you have AFS and are in a state of Inflammation Circuit dysfunction, then you may be at a higher risk of catching viruses. And because of your poor health, you may experience a worse than usual infection. That’s why it’s important to make changes now, while you’re still relatively healthy. Lifestyle changes are essential for AFS recovery, and an important part of that is a healthy diet. If you have AFS, then foods that boost the immune system may help to increase your immune response. It will also improve your overall health safely and naturally, alleviating some of the stress that caused the underlying disorder.


Eating foods that boost the immune system is an easy and effective way to strengthen your body against outside threats. This is incredibly important at the moment, particularly if your body is already weakened because of AFS. If you’re looking to strengthen your immune system, here’s how to do it:

  1. Reduce your stress levels with yoga, meditation, or breathing exercises to alleviate AFS and help rebalance your Inflammation Circuit.
  2. Make sure that you’re eating plenty of immune-boosting foods like berries, oily fish, nuts and seeds, and dark chocolate.
  3. Talk to your doctor about safe and natural ways to boost your immune system.

If you’re concerned about the strength of your immune system, then talk to our team on +1 (626) 571-1234 for more advice on how to boost it naturally or click here to use the Ask The Doctor System.

© Copyright 2020 Michael Lam, M.D. All Rights Reserved.

Dr. Lam’s Key Question

There are certain foods that boost the immune system, and most of them you’re probably already eating. It’s never been more important to be more deliberate about your choices in every part of your life. So, start making better choices with your diet by eating more of these foods.

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