Introduction
Quercetin, also known as onion extract, is widely distributed in the plant kingdom and is an important medicinal component in the flavonoid family. It is also an important dietary antioxidant. It exists in various foods, including fruits, vegetables, tea, alcohol, and other dietary supplements, and is beneficial for health. The reason why Quercetin Supplement is eye-catching is its special antioxidant, anti-inflammatory, and anti allergic effects. It is one of the top plant nutrients and is known as a natural antihistamine, which is also the key to making these vegetables and fruits a superfood.
What is quercetin?
Pure quercetin is classified as a flavonol and is one of the six subclasses of flavonoids, widely distributed in plants.
The name Quercetin has been in use since 1857 and has evolved from the Latin word "Quercetum", meaning oak forest.
In the study, it was found that quercetin has multiple biological characteristics, including antioxidant, anti-inflammatory, antibacterial, antiviral, free radical scavenging, and immunomodulatory activity, which form the basis for potential benefits to overall health and disease resistance.
These substances are natural pigments evolved by plants over hundreds of millions of years. In addition to endowing vegetables and fruits with colorful colors, their most important function is like the immune system, which is the key for plants to resist foreign aggression and prolong life.
The Food Source of Quercetin
Best quercetin is present in various foods, including vegetables such as broccoli, asparagus, scallions, green peppers, tomatoes, and red lettuce, and fruits such as apples, strawberries, grapes, blueberries, cranberries, and blackcurrants.
Bio quercetin is also present in medicinal plants, including Ginkgo biloba, Forsythia suspensa, and ginseng, as well as many seeds, nuts, flowers, bark, and leaves. Green tea and wine are also considered rich dietary sources.
What are the empirical effects (benefits) of quercetin Powder?
1. Quercetin enhances aerobic exercise performance
Lack of physical activity is a common problem worldwide, with approximately two-thirds of adults failing to reach the minimum recommended level of physical activity.
Sports training, such as aerobic exercise, not only promotes personal physical health but may also affect psychological well-being. Due to the interdependence between physical and mental states, a decrease in physical abilities may lead to a decrease in self-esteem.
Many research reports show that regular and moderate exercise training can reduce the risk of cancer, heart disease, diabetes, osteoporosis, obesity, anxiety and depression.
A meta-analysis, consisting of 7 randomized, double-blind, placebo-controlled trials with 288 participants, indicated that quercetin did not significantly improve the performance of promoting aerobic exercise (measured by endurance performance and maximum oxygen consumption (VO2max)).
2. Super quercetin regulates blood pressure
According to the American Heart Association, there are currently 80 million adults in the United States suffering from essential hypertension.
The pathological factors of hypertension are largely due to increased oxidative pressure, increased production of endothelin-1, decreased production of nitric oxide, and improper fluid control caused by excessive stimulation of the renin angiotensin system.
The treatment method depends on the cause of the disease, including dietary changes (reducing sodium intake), weight loss, and increased physical activity.
A systematic literature review and meta-analysis (consisting of 7 studies and 587 participants) indicated that supplementing with quercetin had a blood pressure lowering effect (average -3.04/-2.63 mm Hg, systolic/diastolic blood pressure), with the most significant effect observed when the daily dose was greater than 500 mg and the duration of use was greater than 8 weeks.
3. Quercetin helps with weight loss
Overweight and obesity is a global public health problem. As a risk factor, overweight and obesity will increase the risk of cardiovascular disease, type II diabetes, kidney disease, arthritis, musculoskeletal problems, depression, some cancers, insomnia and chronic fatigue.
In addition to well-known factors that lead to obesity, such as increased intake of high-energy density foods and reduced physical activity.
In addition, there are several different factors present, such as gut microbiota, endocrine disruptors, epigenetics, increasing maternal age, selective mating, sleep debt, and iatrogenic drugs.
A meta-analysis of 9 randomized controlled clinical trials with 525 participants revealed that daily supplementation with quercetin capsules did not significantly affect body weight, body mass index, waist circumference, and waist to hip ratio.
4. Quercetin is beneficial for blood sugar control
Diabetes is a complex chronic disease, which is related to hyperglycemia or hyperglycemia. It occurs in insufficient insulin secretion, insufficient activity or both.
Often feeling thirsty, increased urine output, ketosis and ketonuria are common symptoms of diabetes, and their occurrence is due to abnormal carbohydrate, fat and protein metabolism.
A systematic literature review and meta-analysis (including 9 randomized controlled trials involving 781 patients with metabolic syndrome and related diseases) indicated that quercetin supplementation did not affect fasting plasma glucose, the homeostasis model of assessment estimated insulin resistance, and glycated hemoglobin A1c levels.
However, in subgroup analysis, it was found that the effect of supplementing quercetin on reducing fasting blood glucose was most significant in studies with a daily dose of ≥ 500 mg for ≥ 8 weeks.
5. Quercetin is beneficial for systemic inflammation
Inflammation is the immune system's response to harmful stimuli, such as pathogens, damaged cells, toxic compounds, or radiation, and works by eliminating harmful stimuli and initiating healing processes. It is an important defense mechanism for maintaining health in the human body.
The characteristics of inflammation are redness, swelling, fever, pain, and loss of tissue function, which are caused by the response of local immunity, blood vessels, and inflammatory cells to infection or injury. Uncontrolled acute inflammation may become chronic, leading to various chronic inflammatory diseases.
A meta-analysis, consisting of 7 randomized double-blind controlled studies with 549 participants, indicated that supplementing with quercetin/onion extract had a significant effect on reducing C-reactive protein, particularly in subjects with daily doses greater than 500 mg and CRP less than 3 mg/l.
Another meta-analysis, which included 15 randomized controlled trials, indicated that supplementing with quercetin had anti-inflammatory effects (reducing C-reactive protein and interleukin-6) in participants with disease.
The underlying mechanisms may be related to the inhibition of nuclear transcription factor kB pathway, inhibition of leukotriene formation, interference with AMPK/SIRT1 pathway, and promotion of nitric oxide production.
6. Quercetin regulates blood lipids
Dyslipidemia is one of the important risk factors for cardiovascular disease. According to epidemiological data in the United States, 29% of individuals aged 45 to 84 without clinical cardiovascular disease have dyslipidemia.
Research has shown that plasma total cholesterol decreases by 10%, the incidence of coronary artery disease decreases by 25% after 5 years, low-density lipoprotein cholesterol decreases by 1 mmol/L, cardiovascular disease mortality and non fatal myocardial infarction incidence decrease by 21%.
A systematic literature review and meta-analysis (including 16 randomized, placebo-controlled trials with 1575 participants in metabolic syndrome and related diseases) indicated that supplementing quercetin significantly reduced total cholesterol, low-density lipoprotein cholesterol, and C-reactive protein levels.
In addition, activated quercetin was not significantly helpful in improving triglycerides, high-density lipoprotein cholesterol (HDL-C), and tumor necrosis factor-α (TNF-α) levels.
7. Quercetin prevents upper respiratory tract infections
Acute upper respiratory infection is the most common disease among adults, referring to acute infections in the nasal, sinus, pharynx, middle ear, larynx, epiglottis, airway, and bronchi. The common cold is the most common, usually occurring 2 to 5 times a year.
The common cold may be caused by various pathogenic viruses. Symptoms include mild fever, runny nose, nasal congestion, sneezing, sore throat, cough, and muscle pain.
A randomized, double-blind, placebo-controlled trial (12 weeks, involving 1002 participants of all age groups) indicated that overall, supplementing with compound ingredients containing quercetin did not significantly improve the incidence, severity, and symptom scores of upper respiratory tract infections.
However, an analysis conducted in the same study on participants aged 40 and above (who considered themselves healthy) showed that compared to the placebo group, the daily dose of 1000 mg group had lower severity and total days of upper respiratory tract infections.
8. Quercetin is beneficial for allergic diseases
Allergic diseases are a type of hypersensitive disease in which the immune system responds to substances commonly considered harmless in the environment. In recent decades, the incidence of organ specific allergic diseases such as allergic rhinitis, asthma, and eczema has risen sharply.
In some cases, allergic diseases can be quite mild, but they can also be a real hassle and have a significant impact on daily life. Severe allergic reactions can be life-threatening.
A literature review pointed out that pure quercetin has anti allergic mechanisms such as mast cell activation inhibition, antiviral activity, inhibition of histamine release, reduction of pro-inflammatory cytokines, production of leukotrienes, inhibition of interleukin-4 production, improvement of Th1/Th2 balance, and inhibition of antigen-specific IgE antibody formation, which may be helpful for the treatment or prevention of allergic diseases.
Does Quercetin have any side effects?
For most adults in good health, moderate use (daily dose below 1000 mg for 12 consecutive weeks) of quercetin is safe, and potential side effects or adverse reactions that have been reported include nausea, headache, stomach pain, or tingling sensation in the limbs.
Safety precautions (4 Contraindications for use)
1. Do not use for those with poor liver and kidney function.
2. Pregnant and lactating women should not use it.
3. Do not use in combination with quinolone antibiotics as they may reduce drug efficacy.
4. Do not use drugs that require cytochrome P450 enzyme metabolism together, as it may increase the side effects of these drugs.
