*Article supplied by Fusion Health
A strange name but a powerful nutrient, quercetin (pronounced kwer-see-tin) certainly packs a punch for our immune health in the lead up to winter and allergy seasons.
If you eat a whole food diet, full of fruits and vegetables, then you’re consuming quercetin. Studies show the benefits of quercetin and the interest in its antioxidant activity, immune-supporting and mild-allergy relieving properties.[1-5] Keep reading to find out how quercetin could benefit you.
While you may not be familiar with the nutrient quercetin, it’s been the subject of research for decades, which have shown it has multiple benefits including antioxidant, anti-inflammatory and immune supporting actions plus relief for mild allergy symptoms.
What Is Quercetin?
Quercetin was discovered in 1938 by the Hungarian Nobel prize winner Albert Szent-Gyorgyi along with ascorbic acid (vitamin C); two compounds that go hand-in-hand in nature.[1]
Quercetin was originally called ‘vitamin P’ but was soon renamed when it was found that quercetin was really a flavonoid, with a wide array of health benefits.[2]
Found abundantly in fruits, vegetables, tea and wine, quercetin is a pigment and polyphenol bioflavonoid (plant chemical) which usually occurs alongside other antioxidant nutrients that act together to help to make each other more effective – don’t you just love how plants do that?!
Quercetin Actions and Benefits
Quercetin provides support in two very key areas in the body – inflammation and free radical damage – by providing anti-inflammatory and antioxidant activities.
Inflammation is a necessary part of the immune system’s normal response to injury and infection, but inflammation can also be detrimental to health when it occurs in excess due to lifestyle factors.
Quercetin helps reduce inflammation by preventing some of the major inflammatory cells from being produced in large amounts. Some studies, using cells and animals, have also shown that quercetin may help to prevent inflammatory cells from being produced.[3]
Quercetin also acts as an antioxidant by neutralising harmful free radicals. Free radicals are produced in the body during normal cellular metabolism, and from excessive exposure to the sun, pollution and many chemicals in our environment, food, water and air. A balance between antioxidants and free radicals is vital for normal physiological function.
Relieve allergies and Hayfever symptoms with quercetin
If you’re a sufferer from mild allergies, you’ll be pleased to know that the anti-inflammatory and antioxidant activities of quercetin will assist with your symptoms but it also has a more direct action when it comes to allergies.
You’re likely to be familiar with histamine, released from mast cells, that initiates allergic reactions. Studies on quercetin have helped us to understand that quercetin relieves mild allergy symptoms by stabilising mast cells and, therefore, reducing the release of histamine into the bloodstream.[4]
A study in mild allergies found that quercetin reduced Ig E, a protein that is used as a marker to measure levels of allergic conditions. The results concluded that quercetin helped to reduce the symptoms of mild allergies.[5]
Foods containing quercetin
Quercetin-rich foods are found in a typical healthy diet filled with fruits and vegetables. Because quercetin is a plant pigment, consume foods with rich colours and those you tend to eat with the skin on. Include these high quercetin foods in your diet:
- Apples
- Tomatoes
- Onions
- Grapes
- Cherries
- Citrus fruits
- Leeks
- Shallots
- Berries
- Black and green tea
- Broccoli
- Herbs like parsley and sage
- Kale
- Garlic
- Red wine
- Rocket Green and red lettuces
- Olive oil
Quercetin for a healthy immune system
Quercetin supports immunity too! Make it a quinella and join quercetin with zinc, vitamin C and vitamin D when you need immune support.
Foods to eat in abundance that contain quercetin, vitamin C AND zinc:
- broccoli
- kiwi fruit
- berries such as strawberries, blueberries, blackberries and raspberries.
Although quercetin is only found in small amounts in most foods, a varied diet abundant in plant-based foods can help to provide antioxidant activity, relieve mild allergy symptoms and support the immune system.
Recommended dosage of quercetin
It’s recommended to take from 250 mg up to 750 mg per day of quercetin.[6]
Who should not take quercetin?
While quercetin shouldn’t be avoided in the diet, higher supplemental doses may need to be avoided by some people.
Quercetin supplements can reduce the effectiveness of some types of medication; check with your health professional if you are taking other medications. If you are pregnant or breastfeeding, it’s also best to avoid taking quercetin supplements for the simple fact that not enough is known about taking it when pregnant or lactating.[7]
Quercetin Supplements
Quercetin is great to team up with other herbs and nutrients that relieve inflammation, plus other antioxidants and immune-supporting nutrients.
To support immunity, quercetin plus vitamins C, D and zinc makes for a formidable team for support of healthy immune system function and helping the immune system to fight illness. Fusion Health’s Quercetin Advanced combines quercetin, with vitamins C, D and zinc to support immune system health and function.

Always read the label and follow the directions for use.
To relieve symptoms of mild allergies, herbs like baical skullcap, found in Fusion Allergy, are traditionally used in Chinese medicine to relieve symptoms of mild allergies including hayfever symptoms.
For other inflammatory conditions, consider curcumin from turmeric for the perfect anti-inflammatory duo with quercetin. Find curcumin alongside boswellia, ginger and black pepper in Fusion Curcumin Advanced.
Antioxidant protection can also be found in vitamins A, C, E, zinc, selenium, lycopene or antioxidant-rich fruits and vegetables such as blueberries, blackcurrants, tomatoes, pink grapefruit, herbs and spices. For a high-strength blend of herbal antioxidants to pair with quercetin, try Fusion Revital 8™.
References:
- Bors W, et al. Free Radical Biology and Medicine 1995;19(1):45-52.
- Linus Pauling Institute. Last updated February 2016, accessed February 2022 from https://lpi.oregonstate.edu/mic/dietary-factors/phytochemicals/flavonoids
- Li Y, et al. Nutrients 2016;8(3):167.
- Horowitz RJ. Integrative Medicine. 4th Ed. Elsevier, 2018.
- Jafarinia M, et al. Allergy, Asthma & Clinical Immunology 2020;26(36).
- Drugs.com. Last updated June 2021, accessed February 2022 from https://www.drugs.com/npp/quercetin.html
- RX List. Last updated November 2021, accessed February 2022 from https://www.rxlist.com/quercetin/supplements.htm