Quercitin or quercetin is a flavonoid produced by the metabolism of some plants, which has important antioxidant, anti-inflammatory and even anticancer properties. Let’s find out all the benefits of quercetin proven by science
©rosinka79/123rf
The quercetin is a flavonoid, belonging to the flavonol group, has a wide range of benefits that have made it useful for a variety of different health conditions.
Contained in some plant foods, such as fruits, vegetables, nuts and various seeds, quercitin is also a key component of several medicinal herbs such as ginkgo biloba.
Read also: Glutathione and Quercetin: what is important to know about the supplements of the moment
Quercetin: what is it?
Quercetin is a plant pigment (flavonoid). It is found in many plants and foods, such as red wine, onions, green tea, apples and berries.
It has antioxidant and anti-inflammatory effects that could help reduce swelling, kill cancer cells, control blood sugar and help prevent heart disease.
This compound has been linked to numerous health benefits, including reduced risks of heart disease, cancer, and degenerative brain disorders.
The beneficial effects of flavonoids like quercetin come from their ability to function as antioxidants within the body.
Antioxidants are compounds that can bind to and neutralize free radicals, those unstable molecules that can cause cellular damage when their levels get too high.
The damage caused by free radicals has been linked to numerous chronic conditions, including cancer, heart disease and diabetes.
Quercetin is the most abundant flavonoid we get from food; it is estimated, in fact, that we get to consume from 10-100 mg per day through various food sources.
Foods that commonly contain quercetin include onions, apples, grapes, berries, broccoli, citrus fruits, cherries, green tea, coffee, red wine, and capers.
It is also available as a dietary supplement in powder and capsule form.
Quercetin: benefits
Over the past couple of years, the antiviral benefits of quercetin have been the focus of many studies. However, there are other lesser known benefits, including effects as a senolytic agent against senescence-mediated cancer growth.
According to research, quercetin should be used with caution as it may interact with some antibiotics reducing the effectiveness of the drug.
It can also enhance the effect of some blood thinners, which can increase the risk of bleeding; in addition to these, it can interact with corticosteroids, digoxin, cyclosporine and fluoroquinolones.
Quercitin and the effects on cancer cells
An article published in August 2022 on Nutrition Research investigated the pro-apoptotic effect that quercetin has on aging cells. Apoptosis is the normal, healthy way cells should die.
The paper reviewed preclinical and early-stage data using quercetin as a senolytic agent, the data showed it was effective in preventing or alleviating cancer formation.
The authors examined the importance of cellular aging in tumor cell development, and the effect quercetin may have on suppressing tumor cell proliferation.
A mini review posted on Cancer Letters in 2008 it reviewed previous research, and found that studies had shown that quercetin could prevent chemically induced cancer growth, and epidemiological studies found that it was associated with the prevention of lung cancer.
Other studies have also shown that quercetin is a strong antioxidant and has pro-apoptotic effects on cancer cells, with the ability to block growth at different stages of the cell cycle.
Research has also shown that quercetin can promote cell viability loss and autophagy through several pathways, including those involving mitochondrial function and glucose metabolism.
Data indicate that it may play a role in cancer treatment as it reportedly has synergistic effects in combination with chemotherapy agents and radiation therapy.
Quercetin also showed property chemoprotective and radioprotective, meaning that it is able to protect normal cells from the effects of chemotherapy and radiotherapy.
Quercitin and sleep disorders
The antioxidant properties of quercetin may improve mood-related behaviors in sleep-deprived individuals.
A study published in 2022 divided two groups: one received astaxanthin and one quercetin. Their activities were monitored and brain samples were subsequently collected.
The researchers found that while awake, the subjects experienced anxiety and depression-like behaviors. In the astaxanthin-treated group, brain samples showed increased pro-oxidant activity and increased oxidative stress.
In the quercetin-treated group, these behaviors were reversed. The researchers found, therefore, that quercetin could reduce the anxiety caused by sleep deprivation.
In a study published in 2016, researchers hypothesized that quercetin could reduce manic behavior induced by 24 hours of paradoxical sleep deprivation. Paradoxical sleep is another name given to rapid eye movement (REM) sleep, the deprivation of which has led to chronic conditions such as obesity and stress disorders.
In the study, the researchers found that quercetin blocked the hyperactivity induced by sleep deprivation.
In another study, researchers hypothesized that hippocampal area deficits associated with sleep deprivation could be improved with a preparation of grape seed polyphenol extract, grape juice, and resveratrol.
Quercitin and inflammation of the respiratory tract
Quercetin has been studied for its effect antivirals and has been shown to inhibit the early stages of a flu infection.
It is also a promising agent against Epstein-Barr virus, Zika virus, hepatitis B and rhinovirus, the virus most often responsible for the common cold.
It made sense then, when the Covid-19 pandemic emerged, for researchers to study its effectiveness against the SARS-CoV-2 virus.
In the first months of the pandemic, a review was published which found that the administration of bromelainquercetin, vitamin C and zinc have shown promise in improving clinical outcomes among Covid-19 patients.
In this paper, researchers have identified the antioxidant’s ability to inhibit pro-inflammatory cytokines, and to block cytokine release, as an important property in the fight against COVID-19 disease, which is associated with increased levels of cytokine production.
Additional benefits of quercetin
The property antioxidants e anti-inflammatories of quercetin contribute to the other lesser known benefits of this supplement.
The anti-inflammatory effects of quercetin are very important, as inflammation is at the root of many diseases, including autoimmune diseases, heart disease and cancer.
A review of the literature found quercetin to be a potent anti-inflammatory weapon that can be used in the fight against inflammatory diseases, such as obesity and type 2 diabetes.
Another showed that supplementation could reduce systolic blood pressure and a third study revealed that quercetin supplementation and exercise could reduce atherosclerotic plaque formation.
Quercetin has also shown promise in relieving allergy symptoms. It works by inhibiting the release of histamine and decreasing the production of proinflammatory cytokines and the creation of leukotrienes.
Quercetin has also been studied for the benefits it has on:
- hypertension
- cardiovascular disease
- metabolic syndrome
- non-alcoholic fatty liver disease
- mood disorders
- gotta
- arthritis.
Quercetin from foods and supplements
Considering the broad health benefits quercetin has, it could be a useful supplement whether it’s used to treat an acute or chronic condition or as a long-term preventative measure.
If you’re prone to colds and flu, consider taking it for a couple of months before cold and flu season hits so you can support your immune system.
Side effects
Quercetin is found in many fruits and vegetables, making it safe to consume. Even as a supplement it appears to be generally safe, with little to no side effects.
In some cases, it has been shown that taking more than 1,000 mg of quercetin per day can cause mild symptoms such as headaches, stomach aches or tingling sensations.
When consumed in food, quercetin is also safe for pregnant and nursing women, while studies on the safety of quercetin supplements for the latter category of people are lacking.
Also, as with any supplement, consult your doctor before taking any as it can interact with some medications, including antibiotics and blood pressure medications.
Follow us on Telegram | Instagram | Facebook | TikTok | Youtube
Could it be interesting for you: