Quercetin

What is Quercetin?

Quercetin is a naturally occurring flavonoid found in many fruits, vegetables and beverages. It is best known for its potent anti-inflammatory and antioxidant properties. Quercetin helps protect cells from damage caused by free radicals and may play an important role in supporting the immune system. It is found in high concentrations in foods such as onions, apples, berries and green leafy vegetables.

How does it work in the body?

Quercetin acts in several ways in the body. Firstly, it functions as an antioxidant, meaning it neutralises harmful free radicals that can cause cell damage and accelerate the ageing process. Additionally, quercetin has been shown to have antihistamine properties, making it useful for alleviating allergic symptoms. It can also modulate inflammatory processes by inhibiting the production of pro-inflammatory cytokines.

Scientific benefits

Several studies have investigated the potential health benefits of quercetin. Some of these include:

• Anti-inflammatory effects: A study published in the Journal of Inflammation showed that quercetin can reduce inflammation in the body, which may be beneficial for individuals with inflammatory diseases such as arthritis.
• Antihistamine properties: Research has shown that quercetin can block the release of histamine from mast cells, which may relieve allergic symptoms.
• Antiviral effects: According to a study in the Virology Journal, quercetin can inhibit the replication of certain viruses, which may help protect against infections.
• Improved cardiovascular health: A meta-analysis in the American Journal of Clinical Nutrition suggests that quercetin may help lower blood pressure and improve lipid profiles.

Dosage and recommendations

The recommended dose of quercetin varies depending on individual needs and health goals. Typically, the dose ranges between 500 mg and 1000 mg per day, divided into two to three intakes. It is important to consult a doctor or dietitian before starting supplements, especially if you have underlying health conditions or are taking medications.

Best sources and forms

Quercetin is found in many foods, making it easy to include in the diet:

• Onions: Red and yellow onions are particularly rich in quercetin.
• Apples: Especially the skins of apples contain high levels of quercetin.
• Berries: Blueberries, raspberries and cranberries are good sources.
• Green leafy vegetables: Spinach and kale also contain quercetin.

Quercetin is also available as a dietary supplement in capsule or tablet form, which can be an option for those who have difficulty obtaining enough through diet.

Side effects and warnings

Quercetin is generally considered safe when taken at recommended doses. However, some individuals may experience mild side effects such as headache, gastrointestinal discomfort or allergic reactions. It is important to note that people allergic to onions or apples may react negatively to quercetin. Pregnant and breastfeeding women should consult a doctor before taking supplements containing quercetin.

Frequently asked questions

Is quercetin good for allergies?

Yes, quercetin has been shown to have antihistamine properties, which can help alleviate allergy symptoms.

Can I get enough quercetin from my diet?

Yes, by eating a varied diet rich in fruits and vegetables, you can obtain a sufficient amount of quercetin.

Are there any interactions with medications?

Quercetin can interact with certain medications, including blood thinners. It is important to consult a doctor before starting quercetin if you are on medication.

Can quercetin help with colds?

Some research suggests that quercetin may have antiviral properties, but more studies are needed to confirm its effectiveness against colds.

Is quercetin safe for long-term use?

Quercetin is considered safe at recommended doses, but it is always best to consult a doctor for long-term use.