Health Vitamins & Nutrition Centre, Langley BC
Quercetin benefits - Dr. Axe
Have you ever wondered what makes a superfood super? Or what key superfoods like red wine, green tea, kale and blueberries all have in common?

The answer is quercetin, a natural compound tied to what all of us seek: better longevity, heart health, endurance, immune system and more.

Research even shows that quercetin displays anticancer properties. In fact, there isnt much this powerful antioxidant compound cant do, especially when combined with the health benefits of bromelain, an anti-inflammatory enzyme.

Quercetin is a type of flavonoid antioxidant thats found in plant foods, including leafy greens, tomatoes, berries and broccoli. Its technically considered a plant pigment, which is exactly why its found in deeply colored, nutrient-packed fruits and veggies.

Considered one of the most abundant antioxidants in the human diet, quercetin plays an important part in fighting free radical damage, the effects of aging and inflammation. While you can get plenty of quercetin from eating a healthy diet, some people also take quercetin supplements for their strong anti-inflammatory effects.

According to the Department of Pathology and Diagnostics at the University of Verona in Italy, quercetin and other flavonoids are anti-viral, anti-microbial, anti-inflammatory and anti-allergic agents with potential to be expressed positively in different cell types in both animals and humans. Flavonoid polyphenols are most beneficial for down-regulating or suppressing inflammatory pathways and functions. Quercetin is considered the most diffused and known nature-derived flavonol there is, showing strong effects on immunity and inflammation caused by leukocytes and other intracellular signals.

How Does Quercetin Work and How Much Do We Need?

Research shows that anti-inflammatory foods containing quercetin can help manage a number of inflammatory health problems, including heart disease and blood vessel problems, allergies, infections, chronic fatigue, and symptoms related to autoimmune disorders like arthritis. How exactly do flavonoids like quercetin do so much to benefit us?

It all comes down to high-antioxidant foods ability to be scavenge free radicals. As a major bioflavonoid in our diets, quercetin (a type of polyphenolic antioxidant) helps slow the aging progress because it lessens the effects of oxidative stress on the body. Oxidative stress takes place in all of us but is increased by things like a poor diet, high levels of stress, a lack of sleep and exposure to chemical toxins.

Quercetin plays a role in regulating the immune systems response to outside stressors through cell signaling pathways called kinases and phosphatases, two types of enzyme and membrane proteins needed for proper cellular function.

Quercetin Dosage Recommendations:

There isnt a daily recommended amount of quercetin, so dosage recommendations can vary depending on your health condition. Estimates show that most people typically get between five and 40 milligrams of quercetin a day from eating common plant foods, however if you stick with a nutrient-dense diet overall, youre likely to take in much more as much as 500 milligrams daily according to some reports!

Optimal doses of quercetin have not been established for any specific conditions by the FDA or any other governing health authority at this time, so its up to you and your doctor to decide what amount works best for you. For people who turn to quercetin supplements, common oral dosages are 500 milligrams taken twice daily, but its also definitely possible to experience benefits when taking lower dosages.

Quercetin supplements are available in all types of pills or capsules and are commonly used in formulas along with bromelain, another anti-inflammatory enzyme found in pineapples that is also useful for fighting allergies. When buying quercetin capsules or supplements, make sure to purchase from a reputable brand and read ingredients carefully, since the amount of active ingredient can vary widely depending on the manufacturer (which is one reason its hard to recommend a specific dose).
Benefits of Quercetin

1. Lowers Inflammation

Flavonoids, including quercetin, are important anti-inflammatories because they act as antioxidants, which mean they literally fight the natural process of oxidation that takes place over time as we age. Quercetin can help stop damaging particles in the body known as free radicals, which negatively impact how cells work including damaging cell membranes, changing the way DNA works, increasing cell mutations and causing healthy cells to die.

Research now shows us that inflammation is the root of most diseases, including heart disease, cancer, cognitive decline, some mental disorders and autoimmune disorders. The most well-researched effects of quercetin on fighting inflammation have been found in foods (especially fruits and veggies) that naturally supply flavonoids and other polyphenols, so we still have more to learn about the long-term effects of taking antioxidant supplements to lower inflammatory diseases. At this time, practitioners and patients report using quercetin to effectively fight conditions related to inflammation, including:

hardening of the arteries (atherosclerosis)
high cholesterol
heart disease and circulation problems
insulin resistance and diabetes
eye-related disorders, including cataracts
allergies, asthma and hay fever
stomach ulcers
cognitive impairment
viral infections
inflammation of the prostate, bladder and ovaries
chronic fatigue syndrome
chronic infections of the prostate
skin disorders, including dermatitis and hives

2. Fights Allergies

Quercetin is a natural antihistamine and an anti-inflammatory, making it effective for naturally lowering the effects of season and food allergies, plus asthma and skin reactions. Histamines are chemicals that are released when the immune system detects an allergy or sensitivity, and they are what account for uncomfortable symptoms we face whenever the body has an allergic reaction.

Quercetin can help stabilize the release of histamines from certain immune cells, which results in decreased symptoms like coughs, watery eyes, runny noses, hives, swollen lips or tongue, and indigestion. In fact, its so effective that quercetin is used in ancient Chinese herbal formulas created to block allergies to certain foods (such as peanuts), known as food allergy herbal formulas. Studies show that quercetin, a natural medicine and phytochemical, is equivalent at fighting allergies as some prescription medications, all with little to no side effects.

3. Supports Heart Health

Because of its ability to lower inflammation and oxidative stress, quercetin seems to be beneficial for people with heart and blood vessel-related disorders. For example, eating lots of deeply colored fruits and veggies that contain flavonoids is linked to a lower risk of cardiovascular diease, and even death, in older adults.

Studies done in animal and some human populations show that various types of flavonoids (quercetin, resveratrol and catechins, for example) can help reduce the risk of atherosclerosis, which is a dangerous condition caused by plaque building up within the arteries. Cut-off blood flow in the arteries is one of the primary risk factors for experiencing a heart attack or stroke, which is why cardiac arrest is less likely among people who eat a nutrient-packed diet.

Antioxidants also seem to protect the body from experiencing increases in LDL bad cholesterol and can help regulate blood pressure levels. Certain studies show that quercetin prevents damage to LDL cholesterol particles, and it seems that people who eat the most flavonoid-rich foods typically have healthier and lower cholesterol levels, plus less incidences of hypertension. In fact, if youve ever heard that red wine is good for your heart, thats because its a natural source of quercetin. Its one of the main active ingredients in red wine extract, which is associated with healthier heart function.

4. Helps Fight Pain

Taking quercetin supplements can help lower pain associated with autoimmune conditions, such as arthritis, as well as infections, including those of the prostate and respiratory tract. Thats because quercetin reduces inflammatory pain. Theres some evidence from several small studies that people experiencing bladder pains from infections (causing an urgent need to urinate, swelling and burning) have fewer symptoms when taking quercetin supplements.

Flavonoids are also linked to reduced symptoms of prostatitis (inflammation of the prostate) and rheumatoid arthritis (RA). Theres evidence that when patients with RA switch from eating a typical Western diet to one higher in antioxidant-rich foods (like uncooked berries, fruits, vegetables, nuts, roots, seeds and sprouts), they experience less pain and reoccurring symptoms, making quercetin a natural arthritis treatment.

5. Might Help Improve Endurance

Quercetin is added to some athletic supplements because its believed to help increase athletic performance and endurance, likely because of its positive effects on blood flow. Researchers from the School of Applied Physiology at the Georgia Institute of Technology found that, on average, quercetin provides a statistically significant benefit in human endurance exercise capacity (VO(2max) and endurance exercise performance).

While improvements were at times small, it makes sense that antioxidants like quercetin could boost physical performance since they help increase the health of blood vessels, which carry oxygen and nutrients to muscle and joint tissue.

Other studies also show that quercetin helps increase immune function and prevents susceptibility to illnesses that can occur when someone trains intensely and experiences exhaustion. One study found evidence that taking 500 milligrams of quercetin twice daily helped protect cyclers from developing exercise-induced respiratory infections following periods of heavy exercise.

6. Might Help Fight Cancer

A Boston University School of Medicine study published in the Journal of Biological Regulators and Homeostatic Agents shows a link between a nutrient-dense diet rich in quercetin plus other antioxidants and a lowered risk of cancer. Quercetin seems to have potential chemo-preventive activity and might have a unique antiproliferative effect on cancerous cells, making it an effective addition to any natural cancer treatment approach.

Studies suggest that quercetins cancer-protecting effects result from the modulation of either EGFR or estrogen-receptor pathways. Flavonoids can help stop the processes involved in cell mutation, the growth of tumors and symptoms related to typical cancer treatments, such as radiation or chemotherapy.

Quercetin is considered a safe treatment approach for stopping cancer, and in the future, we might see it used as a natural therapy instead of, or in conjunction with, conventional methods. At this time, the majority of studies done on quercetins effects on cellular functioning have involved animals, so more research is still needed to reveal quercetins specific effects on human cancerous cells. This is especially true when taken in high doses above the amount someone would get from a healthy diet.

7. Helps Protect Skin Health

Capable of blocking mast cells, which are immune cells critical in triggering allergic reactions, inflammatory disease and autoimmune disease, quercetin helps protect skin from the effects of disorders like dermatitis and photosensitivity. Flavonoids like quercetin block the release of many pro-inflammatory cytokines, such as IL-8 and TNF, which helps stop symptoms related to skin inflammation, even in people who dont find relief from other conventional treatments or prescriptions.

Studies have found that quercetins potent antioxidant and anti-inflammatory compounds are natural ways to fight allergic and inflammatory diseases, as well as some prescriptions, when taken in oral supplement form.
Top Natural Sources of Quercetin

All types of tasty red, green and purple-pigmented plants come packed with quercetin for example, red wine, blueberries, apples, red onion and even green tea are some of the best sources of quercetin. The amount of quercetin found in plant foods can vary a lot depending on where theyre grown, how fresh they are, how theyre prepared and so on.

Some of the top sources of quercetin to add to your diet include:

Red wine
Dark cherries and berries (blueberries, bilberries, blackberries and others)
Cruciferous veggies, including broccoli, cabbage and sprouts
Leafy green veggies, including spinach, kale
Citrus fruits
Whole grains, including buckwheat
Raw asparagus
Raw red onion
Olive oil
Black and green tea
Herbs, including sage, American elder, St. Johns wort and ginkgo biloba

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