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Does Quercetin Support the Immune System?

What Is Quercetin?

Quercetin is a flavonoid, which means it's a plant pigment used for its chemical reactions. Flavonoids have been found to have an anti-inflammatory effect that may help manage chronic inflammatory conditions such as allergies and asthma.

It is also a nutraceutical. A nutraceutical is a substance found in some foods that have medical benefits and health-giving additives that can help prevent or treat a disease.

Have you ever wondered what separates a "superfood" from regular food? What, after all, are the similarities between red wine, green tea, kale, and blueberries as superfoods? The answer is quercetin, a natural chemical linked to all of our goals: longer life, heart health, immunity, endurance, and more.

According to a2018 analysis, quercetin is the most widely distributed and studied flavonoid.

Quercetin is a pigment found in various fruits and vegetables, including onions, apples, berries, broccoli, kale, and green tea. Quercetin is one of the most abundant antioxidants consumed in our diet and has potent anti-viral properties by itself. 

The significant advantage of combining quercetin with zinc is that the quercetin will force the zinc into the cell's center, where it can prevent the virus from replicating.

Quercetin and the Immune System

The human immune system is comprised of many different mechanisms that work together to fight off foreign invaders like bacteria, viruses, and fungi. The immune system protects us by destroying harmful cells when they are infected with pathogens—but this process can overreact; when it does, the pathogen-fighting cells attack healthy cells in the body.

Quercetin is a naturally occurring compound found in plants. A new study suggests that Quercetin could protect against the damage done to healthy cells when the immune system overreacts by activating regulatory T cells (Tregs). [1]

Quercetin comes in tablet form. One problem with the supplement is that the body does not absorb it well. A unique form called quercetin chaconne appears to be better absorbed. Many experts recommend taking Quercetin with bromelain, which increases the absorption of Quercetin and many other medications. In addition, many naturopathic physicians recommend taking both Quercetin and bromelain with vitamin C.

Recent studies, published in the Journal of Nutrients in 2016, revealed that Quercetin is a safe and effective nutrient for reducing inflammation and enhancing immune system activities. [2]

The study was released to review the data on Quercetin, which included human clinical trials, animal studies, and in vitro studies.

When it comes to human clinical trials, it is clear that Quercetin helps to improve the immune system.[3]

How Quercetin Works

One of Quercetin's significant advantages is that it may help decrease inflammation in your body. In addition, Quercetin has been found to have potent anti-inflammatory and antioxidant effects in studies. These benefits are helpful for anybody seeking to improve their general health and well-being.

A 2012 study in the Journal of Research in Medical Sciences revealed that Quercetin-vitamin C supplementation reduced inflammation and oxidative stress for eight weeks. [4]

Quercetin was also shown to have significant anti-inflammatory effects in 2006 research, with the ability to inhibit histamine production and cyclin-dependent kinase activities.

Quercetin helps your body reduce inflammation by temporarily blocking the action of histamine and cyclin-dependent kinases (cytokines). Histamines and enzymes are biochemicals that are involved in inflammation, as well as allergic responses. Quercetin helps your body minimize inflammation by restricting its activity.[5]

Anti-inflammatory foods with Quercetin have been shown in studies to help manage a variety of inflammatory health issues, including heart disease and blood vessel diseases, chronic fatigue, infections, allergies, and arthritis, along with other autoimmune disorders. So, what exactly are the health benefits of flavonoids?

It's all about high-antioxidant foods' capacity to "scavenge free radicals."

Quercetin (a type of "polyphenolic antioxidant") helps slow the aging process by reducing oxidative stress on the body.

Oxidative stress occurs in all of us, but it is exacerbated by poor nutrition, high amounts of stress, lack of sleep, and exposure to chemical contaminants.

Quercetin also promotes healthy cell development and performance by altering the immune system's response to external stress using cell signaling pathways known as kinases and phosphatases, two kinds of enzyme and membrane proteins required for normal cellular function.

Why is Quercetin Good for You?

Quercetin is a plant pigment that has anti-inflammatory properties. People use it to treat allergies, asthma, cancer, the common cold, heart disease, hay fever, and more. Some people also take quercetin supplements to lose weight or treat mental conditions like depression and schizophrenia.

Quercetin supplements might also help protect against sun damage and aging, which means they might slow down the signs of aging associated with chronic diseases like heart disease and diabetes. In addition, there is early evidence that quercetin can increase insulin sensitivity in people, possibly slowing or preventing diabetes. Some studies also suggest that it may prevent blood clots.

Quercetin is a type of flavonoid, which are plant pigments with antioxidant properties. Antioxidants help protect the body against free radicals -- unstable molecules that damage cells and contribute to disease. Quercetin seems to strengthen blood vessel walls, making them less susceptible to damage that could lead to atherosclerosis. It has also been shown to reduce the oxidation of LDL (bad) cholesterol, potentially reducing the risk of heart disease and stroke.

Quercetin might also relieve allergy symptoms by blocking certain inflammatory chemicals in the body. In addition, studies show that quercetin may offer some protection against cancer and other health concerns due to its antioxidant and anti-inflammatory properties, but more research is needed.

Quercetin has also been shown to improve blood sugar regulation in people with type 2 diabetes, possibly by increasing how the body responds to insulin. It may also help reduce nerve pain associated with diabetes.

Study results are mixed regarding quercetin's effects on high blood pressure. One study found that people with high blood pressure who took 500 milligrams of quercetin daily for 12 weeks experienced a significant reduction in blood pressure, but another study using similar doses did not find any effect. Therefore, more research is needed to determine if quercetin may help treat high blood pressure.

Who could benefit from taking Quercetin?

Quercetin is an antibiotic that can help cure or reduce symptoms of bacterial infections. People who may benefit from quercetin have an acute respiratory illness, middle ear infection, intestinal disease (such as traveler's diarrhea), urinary tract infections, and pneumonia. 

Quercetin may also help reduce the likelihood of developing specific conditions ranging from heart disease and cancer to asthma, hay fever, and age-related macular degeneration.

In addition, quercetin can promote health by reducing the risk of developing cardiovascular disease, type 2 diabetes mellitus, neurodegenerative diseases such as Parkinson's and Alzheimer's, and maintaining healthy circulation.

Quercetin may help reduce the risk of developing colorectal cancer, leukemia, and pancreatic cancer by killing cancerous cells or halting their development. This antibiotic also has anti-inflammatory properties. Therefore, individuals with arthritis, asthma, allergies, and other inflammatory diseases may benefit from taking quercetin.

Quercetin is one of the most abundant antioxidants found in nature, making it an actual super nutrient. In addition, the chemical structure of quercetin allows it to be supremely bioavailable and cross cell membranes readily. It also acts as an antioxidant by scavenging free radicals, which are unstable molecules that can damage cells in the body. Crossing the cell membranes helps reduce oxidative stress that contributes to chronic diseases, including heart disease, cancer, and cataracts.

Quercetin may provide different health-related benefits when taken alone or when combined with other nutrients, or when used as part of a dietary supplement regimen intended to improve overall health. Therefore, any individual interested in taking quercetin, whether to address a specific health concern or general health support, should first consult their doctor.

Quercetin can be found in fruits, vegetables, and herbs. The three primary dietary sources of quercetin are onions (16 mg per 100 g serving), capers (66 mg per 100 g serving), and red wine (7.2 mg per 100 mL serving). The recommended intake of quercetin for adults is between 50-200 mg daily.

It has been estimated that quercetin accounts for around half of the antioxidant capacity of onions, grapefruit, capers, leeks, and apples.

Are There any Side Effects Related to Quercetin?

Quercetin is considered a safe and well-tolerated dietary supplement. Side effects may include headaches (around 38%) and gastrointestinal side effects such as nausea (29%), heartburn (15%), stomach upset (15%), diarrhea (8%), bloating (4%), and gas (3%). However, these complaints are typically mild and generally resolve quickly with no long-term adverse effects.

If side effects are experienced, they are most likely to occur within the first few days of taking quercetin. These complaints are typically mild and resolve quickly with no long-term adverse effects.

Quercetin can interact with some medications, including antiplatelet or anticoagulants (drugs intended to reduce the formation of blood clots). Therefore, it may increase the risk of bleeding if taken together with these medications.

It is also possible that quercetin can interfere with some diagnostic tests. Thus, it is important to consult one's physician before taking any supplement, including quercetin.

There's no evidence that quercetin supplements are unsafe for expectant or nursing moms but we would always recommend you get in touch with your health practitioner before taking any supplements if you are pregnant or could be pregnant or breastfeeding.


Quercetin is a supplement that may help you maintain healthy immune function and promote your overall health. Quercetin can be found in many fruits, vegetables, and herbs; the three primary dietary sources of quercetin are onions (16 mg per 100 g serving), capers (66 mg per 100 g serving), and red wine (7.2 mg per 100 mL serving).

The recommended intake for adults is between 50-200mg daily. Side effects from taking this supplement include headaches or gastrointestinal side effects such as nausea or diarrhea, which typically resolve quickly with no long-term adverse effect.

You can also find quercetin in our  Immune Support Supplement, which has been specifically designed to provide high doses of nutrients that have been found to reduce the incidence of infection and calm inflammation within the body. With the addition of bromelain, zinc and selenium to Immune Support, this supplement will ensure you are getting the most of the quercetin you consume.

If you have any questions about using this product to support your health goals, please reach out to us and/or consult a health practitioner before beginning use.