Are you aware of the health benefits of onions? Although onions are commonly used for flavoring, onions are a nutrient-dense superfood that contains quercetin, an antioxidant that promotes multiple health functions. So, what are quercetin supplement benefits? Should you consider including a quercetin supplement in your diet?
Get answers to common questions about the benefits of quercetin supplements, including how quercetin supplements support health and the best way to include one in your diet. Use the links below to jump ahead to a topic of interest.
What Is Quercetin and Where Is It Found?
Quercetin is a flavonoid (a type of plant compound known for its antioxidant properties) found in various fruits and vegetables. Some of the richest sources include onions, capers, apples, berries, grapes, green leafy vegetables, and honey, as well as green and black tea. Onions contain a high amount of quercetin, with the outer layers containing the highest concentration.1 The unique biological properties of quercetin are linked to maintaining the body’s natural inflammatory response and limiting oxidative stress to promote overall health.*
Potential Applications of Quercetin
Quercetin displays antioxidant and immunomodulatory properties2, in addition to possessing mast cell stabilizing3 and gastrointestinal cytoprotective activities4. Quercetin supplement benefits have been attributed to these two primary properties of the flavonoid:
- Antioxidative properties of quercetin: Quercetin’s antioxidant properties enable it to regulate the enzyme-mediated and non-enzyme-dependent antioxidant defense system.* It also regulates cell signaling pathways triggered by reactive oxygen species (ROS) to promote the antioxidant defense system.5
- Immunomodulatory properties of quercetin: Quercetin supports a healthy immune response by modulating immune cells such as dendritic cells, T-helper cells, neutrophils, and microglia, making it a promising therapeutic botanical compound for various immune-related conditions.6,7,8,9
The following table summarizes the potential beneficial applications of quercetin.
System |
Beneficial Applications |
Cardiovascular Health* |
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Immune Health* |
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Renal Health* |
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Skin Health* |
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Gastrointestinal Health* |
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How Does Quercetin Support Cardiovascular Health?
Oxidative stress is closely related to several cardiovascular disorders. The antioxidant and immunomodulatory properties of quercetin help mitigate oxidative stress and free radicals that can damage cardiovascular tissues.* The following table summarizes how quercetin benefits your heart.*
Quercetin and Heart Health* | |
Inhibiting Oxidation of Low-Density Lipoprotein (LDL)* |
|
Helping Maintain Normal Blood Pressure* |
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Inhibiting Expression of Adhesion Molecules* |
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Maintaining a Normal Inflammatory Response in Fat Cells and Support Healthy Glucose Metabolism* |
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How Does Quercetin Support Immune Function?
Quercetin alters several cell signaling pathways that down-regulate adverse allergic reactions and help maintain normal inflammatory responses.* The following table highlights how quercetin supports immune function and strengthens the body’s natural defense mechanisms.*
Quercetin and Immune Function |
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Factors Affecting Quercetin Absorption in the Body
The upper segment of the small intestine absorbs the majority of quercetin.24 Post-absorption, quercetin undergoes metabolization in various organs, including the liver, small intestine, colon, and kidney. Quercetin and its metabolites are finally excreted through urine.
Historically, quercetin supplements have shown poor absorbability and, therefore, bioavailability.25 The key factors affecting quercetin’s absorption in the body are:
- Low Aqueous Solubility (does not dissolve well in water)
- Poor Permeability (does not easily get through the intestinal barrier)
- Short Biological Half-Life (quick elimination)
- Instability in the stomach and intestine (easily broken down by stomach acid and other digestive molecules)
Extensive First-Pass Metabolism in the Liver (quicker biotransformation into other molecules)
Quercetin Supplement Formulations
Quercetin accounts for 75 percent of a person’s daily estimated flavonoid intake, ranging from 50 – 800 mg/day.26 It is worth noting that quercetin intake through food sources mostly depends on consuming fruits, vegetables, and tea. So, even if you consume 10 – 100 mg of quercetin daily through different food sources, a supplement formulation can fill any nutritional gaps to help you realize quercetin’s benefits.
Commercially formulated quercetin supplements are available in oral (tablet, capsule, powder), intravenous (injectable formulations), intranasal (spray, nasal drops), and topical (ointments, gels, sprays) formats. A quercetin capsule or a coated tablet typically contains 400 – 600 mg of the active nutrient.
Novel Formulations
Novel formulations that have alternative delivery systems can overcome the absorbability and bioavailability challenges of quercetin supplements. The following benefits of nano-formulated molecules enhance the overall efficacy of quercetin supplement absorption.
- Nanoformulated molecules achieve a larger surface area per molecule than their raw material counterparts.
- Such molecules can be customized for targeted delivery to the correct part of the intestine, protecting them from early degradation and promoting optimal absorption.
- Nanoformulated nutrient delivery also enables the controlled release of quercetin molecules at the desired point in the intestinal tract.
FAQs: Frequently Asked Questions About Quercetin Supplement Benefits
Are there side effects to taking a quercetin supplement?
There is no significant reported toxicity or side effects of quercetin, and its intake as a nutritional supplement at one gram daily is generally considered safe. However, there is limited data on the prolonged usage of quercetin at levels at or above one gram daily for longer than 12 weeks.27 Ingesting too high amounts of quercetin can cause unwanted effects, such as depletion of intracellular glutathione content.28
The complexity of potential interactions of prolonged quercetin intake indicates that quercetin use as a supplement should be taken after medical consultation.
Can I take a quercetin supplement with a prescription medicine?
Quercetin can interact with certain medications by reducing their absorption and effectiveness and raising the risk of side effects. Consult a health-care practitioner to know about potential contraindications before including a quercetin supplement in your diet or taking one with a prescription medication.
How do I determine the efficacy of a quercetin supplement?
The efficacy of a quercetin supplement lies in enhanced absorption and bioaccessibility of the active nutrient molecules.
QuerciSorb QR® — innovative quercetin supplement formulations developed by Tesseract Medical Research as a quick-release or sustained-release format — incorporate a proprietary nanomolecular nutrient delivery technology (CyLoc® – DexKey®) to enhance the solubility and absorption of quercetin.*
QuerciSorb Immuphore SR® contains quercetin along with additional immune-supporting ingredients, including vitamins C and D, and zinc, to promote healthy immune function.*
Tesseract’s proprietary CyLoc® – DexKey® nutrient delivery nanotechnology further enhances the absorption of quercetin molecules at the desired point in the intestinal tract. The unprecedented absorption unlocks quercetin supplement benefits to support optimal cardiovascular health and immune function.*
The power of Tesseract supplements lies in enhancing palatability, maximizing absorption and bioavailability, and micro-dosing of multiple nutrients in a single, highly effective capsule. Shop products on our website and learn more about how they can help support your cardiovascular health and immune function.*
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