9 Nutrients to support your immune system, and where to find them.

Food is Medicine

Food really is medicine, and there are specific nutrients that are particularly valuable in supporting our immune systems. The following are what I believe to be the top immune supporting nutrients based on current research.

Zinc
Quercetin
Vitamin C
Glutathione
Vitamin D
Vitamin A
Probiotics
Prebiotics
Omega-3 Fatty Acids

Which foods are good sources of these nutrients?

Zinc

Zinc is a type of metal and an essential trace element. It’s called “essential” since your body can’t make its own and you must obtain it from your diet.

Zinc benefits the body in many ways — it helps with hormone production, proper growth and repair, promotes optimal digestion, skin health and vision and supports the immune system.

With regards to immune support – Research shows that this essential mineral can help with development of immune cells and interfere with the molecular process that causes mucus and bacteria to build within the nasal passages.⁽¹⁾

It also helps control inflammation and prevents elevated inflammatory responses (including the release of cytokines).

One study found that when zinc supplements were administered within 24 hours of onset of cold symptoms, the duration of symptoms was significantly reduced compared to the control group that didn’t supplement with it. Fewer patients in the zinc group had cold-related symptoms five and seven days after experiencing the first symptoms compared to those who did not take it.

Zinc deficiency is known to be a common nutrient deficiency in children and adults ⁽²⁾, so ensuring optimal zinc levels is an important part of any immune support protocol.

For most nutrients, there are a few food sources that will provide most of a day’s supply on their own. Other than oysters, this is not true for zinc. Because of this, you’ll need to have multiple contributors most days to reach your recommended intake level. (Source: www.WHfoods.org)

*Soaking beans, seeds, and grains for several hours, even allowing sprouts to form, may significantly improve zinc bioavailability from these foods due to the reduction of phytic acid which covers them.

Quercetin

Quercetin is a plant pigment and flavonoid.

Flavonoids are natural compounds (phytonutrients) found in fruits and vegetables. Along with carotenoids, they are responsible for the vivid colours in fruits and vegetables (now you know why it is important to Eat The Rainbow!).

There are six different groups of flavonoids – each playing a vital role in maintaining good health and protecting your body from everyday toxins and stressors. Flavonoids are also powerful antioxidants and anti-inflammatories.

Inflammation is one of your body’s immune responses. Allergens, germs, toxins, and other irritants can trigger inflammation (now considered one of the root cause of disease ⁽⁴⁾). Flavonoids may help your body modulate that inflammatory reaction.

One of the best-known flavonoids is quercetin.

PS: Cooking and long-storage can change the flavonoid make up in fresh fruits and vegetables. According to World’s Healthiest Foods, up to 80 percent of some flavonoids can be lost in the cooking process.

"Quercetin is known for its antioxidant activity in radical scavenging and anti-allergic properties characterized by stimulation of immune system, antiviral activity, inhibition of histamine release, decrease in pro-inflammatory cytokines…”

healthline.com

Vitamin C

This is one immune supporting nutrient we are all familiar with! But there are some potent sources of Vitamin C that may be new to you.

Vitamin C is a water-soluble vitamin found in many types of fruits and vegetables. It is one of our most important antioxidants to neutralize and mop-up free radicals and modulate inflammation. By doing so, it reduces the risk, severity and length of disease.

Your body also uses vitamin C for both the production and uptake of other compounds (such as collagen, neurotransmitters, amino acids and iron.)

There are plenty of foods (fruits AND vegetables) high in vitamin C, making it super easy (and delicious) to get in your daily dose.

Glutathione

Glutathione is often called the “master antioxidant,” as it assists in boosting other antioxidants like vitamin C and vitamin E.

Glutathione plays an important role in helping your immune system stay strong and ready to fight infections in two important ways:

The proper function of the T-cell lymphocytes. This enables the frontline soldiers of your immune system to increase in numbers.
Stimulating the production and activation of your natural killer (NK) cells (our first line of defence against viral or bacterial infections) and as well as supporting your immune response to viruses, bacteria and parasites. ^{(9) (10) (11)}

The human body produces glutathione naturally and we can support this process by consuming foods high in sulphur and sulforaphane. (Sulphur and sulforaphane are required for the production and synthesis of glutathione.)

Sulphur-rich foods:

Garlic
Shallots
Onion

Sulforaphane-rich foods:

Broccoli
Brussels Sprouts
Cauliflower
Kale
Watercress
Mustard Green

Foods naturally high in glutathione include:

Mushrooms (porcini, oyster, shiitake, and maitake especially)
Spinach
Avocados
Asparagus
Okra

Turmeric and Milk Thistle also boost glutathione levels naturally.

Increased intake of vitamin C also increases glutathione levels. ⁽¹²⁾ See Vitamin C info above.

Vitamin D

Vitamin D is a fat-soluble nutrient essential to the health and functioning of your immune system.

Vitamin D enhances the pathogen-fighting effects of your white blood cells and decreases inflammation, which can contribute to ill-health.⁽¹⁵⁾ Low vitamin D levels are associated with an increased risk of upper respiratory tract infections, including influenza and allergic asthma. ⁽¹⁶⁾

Vitamin D has been highly researched in connection with COVID-19. Studies have shown that Vitamin D can expedite healing and stall inflammation in the respiratory system. ⁽¹⁷⁾

Vitamin D is produced from cholesterol in your skin upon exposure to sunlight. It then travels through your bloodstream and into cells.

So the very best source of this essential nutrient is exposure to sunlight – that is bare skin without sunscreen on. Since we don’t generally spend sufficient time in the sun, with sufficient skin exposure and without sunscreen, even people living in sunny climates are being found to be deficient in this important vitamin.

While very few foods contain significant amounts of this vitamin, the best dietary sources of vitamin D are:

Cod Liver Oil
Wild Fatty Fish such as salmon, mackerel, sardines and trout
Organic Egg Yolks
Beef Liver
Ghee
Hemp Seeds
Mushrooms such as morels, chanterelles, chaga, shiitake, maitake, reishi, turkey tail, button, oyster, shimeji (especially if they are exposed to or dried under UV light or sunlight.)

The Magic of Mushrooms
Like people and animals (and unlike plants) mushrooms can convert ultraviolet light from the sun into vitamin D!

Vitamin A

Vitamin A is an important fat-soluble vitamin and one of our most important antioxidants, along with vitamin C and glutathione, which helps reduce inflammation, fight oxidative stress and clean up free radicals when we’re sick, helping us recover more quickly.

Vitamin A is found in two primary forms: active vitamin A (also called retinol) and beta-carotene.

Retinol comes from animal-derived foods and is a type of “pre-formed” vitamin A that can be used immediately by the body.

The other type is pro-formed vitamin A – also known as Beta-carotene. This form is found in yellow, orange and red fruits and veggies, and leafy greens. Beta-carotene needs to first be converted to retinol, the active form of vitamin A, in order to be used by the body.

Probiotics

Probiotics are beneficial bacteria that live in our digestive tract.

These beneficial bacteria digest our food, synthesise vitamins and support our immune systems by inhibiting the growth of harmful gut bacteria and promoting the production of natural antibodies.

They support our brains for optimal mood, focus, and attention by producing over 90% of our neurotransmitters, serotonin and dopamine; help with detoxification, and even produce their own antimicrobial and anticancer compounds!

Probiotics are found in natural environments, healthy soil (free of pesticides), on unwashed organic produce and in fermented foods.

Prebiotics

Prebiotics are the food and fuel for the probiotics!

Consuming pre-biotic-rich foods is just as important as consuming probiotic-rich foods. As the probiotics are living organisms – they require food too.

Prebiotic foods are those rich in inulin such as:

Raw Chicory Root
Raw Jerusalem Artichoke
Raw Dandelion Greens
Raw Garlic
Raw Leeks
Onion
Flaxseeds
Baobab Fruit
Raw Cacao
Seaweed
Agave Plant
Green Banana

Resistant starch is also a powerful prebiotic. You can find resistant starch in cooked and cooled rice and potatoes. Hello Potato Salad!

Omega Fats

Omega-3s are a specific type of polyunsaturated fatty acid.

The four most common omega-3s found in food are ALA, EPA, ETA and DHA.

Your body doesn’t produce omega-3s on its own, which means they are “essential fatty acids” — you have to consume them.

These essential fats have anti-inflammatory properties which help reduce inflammation in your body and tissue (inflammation is now considered one of the root causes of disease). New research also shows that they can activate and inhibit different types of immune cells, therefore further helping you stay healthy. ⁽³⁵⁾

Omega-3 essential fatty acids also optimize brain and cognitive function, support positive mood, benefit attention and focus, and even give us healthy skin and hair!

Want to get more info like this?

The Mila’s Meals #notjustacookbook book has a detailed ingredient glossary with nutrient information for 156 different foods!

Source and references:

Thåis page contains affiliate links, which means I may earn a small commission if you click the link then purchase a product or service from the third party website. Please read my full disclosure here.

Disclaimer:

Each person’s physical, emotional, and spiritual condition is unique. The information in this article is intended for your educational use only and is not a substitute for professional medical advice, diagnosis, or treatment. Please consult your doctor for matters pertaining to your specific health and diet. The author of this article is not held responsible for any adverse effects or consequences resulting from the use or misuse of any information, suggestions or procedures described herein. Always seek the advice of your physician or other qualified health providers with any questions you may have regarding a medical condition and before undertaking any diet, supplement, fitness, or other health program.

Our award-winning cookbook is here!