Quercetin, a flavonoid found in leaves, seeds, flowers and fruit, is the plant kingdom’s first line of defense against threats – including infections and environmental toxins. Now, researchers are finding that this natural protector can extend an impressive range of benefits to humans as well – especially when it is used with vitamin C, a powerful antioxidant in its own right.From reducing inflammation to alleviating allergies to protecting the heart and brain, quercetin seems designed to selectively target disease and dysfunction – without dangerous side effects.
Discover a ‘laundry list’ of beneficial effects in taking quercetin and vitamin C
1) First and foremost, quercetin is a powerful antioxidant, capable of scavenging harmful free radicals – such as reactive oxygen species – that can cause oxidative stress and trigger a wide variety of degenerative disease.
2) In addition to neutralizing free radicals, quercetin enhances the activity of other antioxidant enzymes produced in the body. In particular, quercetin promotes the expression of glutamate cysteine ligase – which is needed for the production of glutathione – the body’s ‘master antioxidant.’
3) Quercetin has been shown to protect against heavy metal toxicity, with chelating ability for aluminum, cadmium, nickel, cobalt, and lead. In animal studies, quercetin has been found to mitigate lead toxicity, reducing its concentration in the bloodstream.
4) A powerful anti-inflammatory agent, quercetin interferes with the expression of cyclooxygenase, or COX, a pro-inflammatory molecule. As inflammation has been shown to be at the root of many diseases, including cancer, this makes quercetin a powerful tool in nature’s disease-fighting arsenal.
5) Quercetin has a time-honored place in herbal medicine, especially when it comes to allergy relief. Research has shown that quercetin inhibits the release of histamine from mast cells, thereby reducing allergy symptoms such as watery eyes, itching and hives.
In fact, one study showed quercetin to be more effective than the prescription drug cromolyn against contact dermatitis. Bonus: unlike cromolyn, which must be taken at the time of the trigger to be effective, quercetin can be taken ahead of exposure for preventive effect.
6) Quercetin not only reduces histamine levels, but also decreases the number of leukocytes in the lungs and bloodstream, relaxes smooth muscles in airway passages and restores elasticity of lung tissue. This group of benefits means it has possible applications for treating COPD and asthma.
7) Quercetin is currently being studied for its ability to prevent life-threatening anaphylactic reactions that occur with allergies to foods, such as peanuts. In animal studies, quercetin showed the ability to block intestinal inflammation, a hallmark of serious allergic reactions.
8) Quercetin has an impressive complement of properties that help it provide natural protection against heart disease. It protects cells that line the fragile walls of blood vessels, and also protects the extracellular collagen matrix from oxidation. In addition, it lowers levels of LDL cholesterol – while raising beneficial HDL.
9) In both animal and human studies, quercetin decreases high blood pressure – while leaving normal blood pressure unaffected. It accomplishes this by suppressing production of a blood vessel-constricting substance called endothelin-1 – the same mechanism of action as pharmaceutical ACE inhibitors such as captopril.
In animal studies, quercetin completely inhibited cardiac hypertrophy, a consequence of untreated high blood pressure.
10) Quercetin also reduces the risk of heart attack and stroke by decreasing the “stickiness” of blood platelets. In addition, it stimulates production of beneficial nitric oxide, which dilates and relaxes blood vessels to enhance circulation.
11) Quercetin shows great promise in fighting depression. Animal studies have shown that quercetin inhibits the metabolism of serotonin and dopamine in the brain by inhibiting monoamine oxidase – the same method by which the MAO inhibitor class of antidepressants work. It also decreases blood levels of stress hormones, including cortisol.
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12) In cell studies, researchers found that quercetin protects neurons against oxidative stress induced by toxins. Researchers are hopeful that quercetin can be useful in treating neurodegenerative conditions such as Alzheimer’s disease and Parkinson’s disease.
13) Quercetin not only helps prevent cancer by protecting cells from oxidative stress, inflammation and damage to DNA, but has been found to suppress the growth and spread of many different types of cancer cell lines, including cancers of the breast, lung, prostate, liver and esophagus.
When administered along with a carcinogen in animal studies, quercetin drastically reduced the growth and metastasis of cancer cells – as well as the incidence of cancer. By sensitizing cancer cells to conventional chemotherapeutic drugs, quercetin increases their effectiveness, thereby cutting down on side effects of toxic drugs by allowing smaller amounts to be effectively used.
Finally, in a 2010 study published in Carcinogenisis, researchers found that a quercetin-rich diet could reduce the incidence of lung cancer in smokers by a stunning 65 percent.
14) Quercetin mounts an all-out offensive on diabetes by improving insulin response, controlling blood sugar, reducing inflammatory markers, increasing the number of islets in the pancreas, and improving pancreatic and liver function. It also inhibits an enzyme, aldose reductase, which contributes to diabetes complications such as peripheral neuropathy and cataracts.
15) Quercetin blocks the replication of rhinovirus, the culprit behind the common cold, as well as the Influenza A virus. In a 2009 study published in the European Journal of Pharmaceutical Sciences, quercetin was more effective than TamiFlu –the gold standard of pharmaceutical antiviral medications — in inhibiting viral replication.
Quercetin has been also been shown to protect against respiratory tract infections in athletes undergoing rigorous physical training.
16) Quercetin’s benefits extend to the gastrointestinal tract as well. Researchers found that it enhances the production of anti-inflammatory substances by beneficial gut bacteria – a promising development when it comes to treating inflammatory bowel disease.
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17) Quercetin has powerful antibacterial effects. In cell studies, the polyphenol inhibited the growth of the “staph” pathogen S. aureus – and was even effective against methicillin-resistant S. aureus, or MRSA. In other research, quercetin was found to combat H. pylori, the bacteria responsible for stomach ulcers.
18) Finally, quercetin can even help maintain the structure of bones. Research has shown that it can help prevent – and even reverse – bone loss and osteoporosis, while improving the micro-architecture of bone tissue.
To enhance the absorption of quercetin, natural health experts recommend taking it along with vitamin C. Before taking quercetin and vitamin C, discuss the matter with your healthcare provider, who can help you to decide what’s best for you – especially if dealing with a serious health issue.
By the way, pectin, healthy fats, resveratrol, curcumin found inside turmeric and EGCG – or epigallocatechin gallate – from green tea can also promote quercetin absorption.
Every day, research seems to reveal more of quercetin’s extraordinary range of benefits, confirming this versatile polyphenol’s position as an emerging superstar in the field of natural therapies.
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