Quercetin: what it’s good for & where to find it

1. Introduction: what is quercetin?

Quercetin is a secondary plant compound, or phytochemical, known for its antioxidant and anti-inflammatory properties. It occurs in many foods, including apples, onions, berries, lemongrass and green tea as well as Guayusa tea. It is valued as support for the immune system, the health of the gut and overall cell health. But what exactly is quercetin good for? It protects the cells from damage caused by free radicals, reduces inflammation and can even help with histamine intolerance.

In this article, you’ll find out which foods are especially rich in quercetin, which plant sources you can choose, and what health benefits this versatile compound offers. You’ll also find an overview of research, possible side effects and tips for using it safely. Whether you’re considering it for your immune system, your gut or as a food supplement, you’ll find the key information here.

Contents

1. Introduction: what is quercetin?
2. What is quercetin good for?
   1. Quercetin as an antioxidant
   2. Anti-inflammatory properties
   3. Quercetin for the immune system
3. Quercetin in the diet
   1. Quercetin in foods
   2. Plants rich in quercetin
   3. How to get enough
4. Quercetin and its effects
5. Safety and side effects
6. Conclusion

2. What is quercetin good for?

Quercetin is a versatile plant compound with health-promoting properties. It plays an important role as an antioxidant, neutralising free radicals and thereby helping protect cells from damage. It also has anti-inflammatory properties, which can be beneficial for chronic inflammation and conditions such as arthritis. There’s more: quercetin also supports the immune system, strengthening the body’s defences and making it more resistant to infections.

Here, we take a closer look at the three main areas in which quercetin is especially useful: its role as an antioxidant, its anti-inflammatory properties and its importance for supporting the immune system.

2.1 Quercetin as an antioxidant

Quercetin is one of the most effective natural antioxidants and protects your cells from damage caused by free radicals. These can arise from environmental factors such as stress, UV radiation and pollutants. They may accelerate ageing and increase the risk of chronic disease.

As an antioxidant, it neutralises free radicals before they can cause damage, helping to protect cell health. Studies show that this plant compound plays an important role in preventing oxidative stress and helps to slow skin ageing, protect the cardiovascular system and strengthen the immune system.

By adding foods such as apples and berries, Guayusa tea or lemongrass to your diet, you can enjoy their antioxidant properties and support your health over time.

2.2 Anti-inflammatory properties

Quercetin is known for its anti-inflammatory properties, which may be helpful in chronic conditions such as arthritis or inflammatory bowel disease. It may work by inhibiting the activity of pro-inflammatory enzymes such as cyclooxygenase (COX) and reducing the production of inflammatory molecules such as cytokines.

Studies have shown that quercetin can help relieve inflammation by reducing oxidative stress and modulating the immune response. These properties make it a promising natural compound for addressing inflammatory processes.

2.3 Quercetin and the immune system

Quercetin supports your immune system in several ways. It strengthens the body’s defences by promoting the activity of immune cells such as macrophages and T cells, and inhibits the production of pro-inflammatory cytokines. It also acts as an antioxidant, supporting immune function.

Another study shows that quercetin can help with the prevention of infections by inhibiting viral replication and increasing the resistance of the body to pathogens. These findings make quercetin an effective natural active compound for supporting the immune system.

3. Quercetin in the diet

Quercetin is a natural constituent of many plant foods and plays an important role in a healthy diet. It is found mainly in fruit, vegetables, herbs and some drinks, including lemongrass tea, Guayusa tea and green tea. By choosing the right foods, you can meet your needs naturally.

Here, we’ll show you which foods are especially rich in quercetin, which plant sources are available and how to add them effectively to your daily diet.

3.1 Quercetin in foods

Foods rich in quercetin are varied and easy to include in everyday meals. Because quercetin is found only in plants, these foods are suitable for vegans too. Onions, apples, berries and broccoli are especially rich in this secondary plant compound. They contribute to a balanced diet and provide antioxidant and anti-inflammatory benefits.

According to a study, red onions contain the highest concentrations of quercetin, followed by apples and certain berries, such as blueberries and blackcurrants.

For more information about foods with health-promoting ingredients, read our article on the effects of lemongrass tea, which also contains quercetin, as well as citral and apigenin.

3.2 Plants rich in quercetin

Quercetin is a natural flavonoid found in many plants. Here are ten plant foods with particularly high quercetin content, measured in milligrams (mg) per 100 grams (g):

• Capers: 233.8 mg/100 g
• Red onions: 35.0 mg/100 g
• Asparagus: 14.0 mg/100 g
• Kale: 7.1 mg/100 g
• Blueberries: 7.0 mg/100 g
• Lingonberries: 13.0 mg/100 g
• Apples: 4.9 mg/100 g
• Broccoli: 3.0 mg/100 g
• Spinach: 4.0 mg/100 g
• Green beans: 3.9 mg/100 g

These plants are rich in quercetin and offer other health benefits too.

You can also add quercetin to your daily routine through a simple drink. Try teas such as lemongrass tea, hibiscus tea (which contains small amounts) or Guayusa tea.

3.3 How to get enough quercetin

Here are two practical examples of how to meet your daily needs without taking food supplements:

1. Quercetin-rich salad with red onions and apples

• Ingredients: 1 red onion, 1 apple, a handful of spinach, 50 g walnuts, 1 tablespoon olive oil and 1 teaspoon lemon juice.
• Method: Thinly slice the onion and apple. Put them in a bowl with the spinach and walnuts. Mix the olive oil and lemon juice to make a simple dressing. Pour it over the salad and enjoy.
• Benefits: Red onions provide around 35 mg per 100 g, while apples add another 4.9 mg per 100 g.
• Drink: Guayusa tea with hibiscus

2. Blueberry and lemongrass tea smoothie

• Ingredients: 200 g blueberries, 1 cup cooled lemongrass tea, 1 banana and 1 teaspoon honey.
• Method: Put the blueberries, lemongrass tea, banana and honey in a blender and blend until smooth and creamy. Enjoy straight away.
• Benefits: Blueberries provide around 7 mg per 100 g, while the lemongrass tea adds more flavonoids to the smoothie.

With simple recipes like these, you can naturally top up your quercetin intake with plant foods while enjoying healthy, tasty dishes.

4. Quercetin and its effects

Here’s an overview of the six most important effects of quercetin:

• Protects cells from damage by free radicals thanks to its antioxidant properties
• Reduces inflammation and helps relieve chronic inflammatory conditions
• Strengthens the immune system and increases resistance to infections
• Supports gut health and has a positive effect on the gut microbiome
• May help with histamine intolerance by inhibiting the release of histamine
• Promotes heart health, helping to regulate blood pressure and cholesterol levels

For a much more detailed look at its effects, read our article Effects of quercetin. It offers a deeper insight into its health benefits and the scientific background.

5. Safety and side effects

Quercetin is generally considered safe, particularly when it is obtained through the diet. However, occasional side effects may occur with high doses of food supplements or in sensitive people. Here are the three most common side effects of quercetin:

• Digestive problems such as nausea, stomach cramps or diarrhoea at high doses
• Headaches and dizziness, especially when taking quercetin supplements for the first time
• Allergic reactions such as skin rashes or itching in sensitive people

To avoid side effects, stick to the recommended dose and choose high-quality products. Find out more in our article on quercetin side effects.

6. Conclusion

Quercetin is an impressive secondary plant compound with a wide range of health benefits. Whether as an antioxidant, an anti-inflammatory compound or a way to support the immune system, quercetin offers many ways to promote your health naturally. By regularly eating quercetin-rich plants and foods such as apples, onions and berries, you can support your body while benefiting from the other nutrients in these foods.

Drinks such as our lemongrass tea, which is rich in flavonoids, and Guayusa tea are an excellent way to enjoy quercetin and other beneficial ingredients. Hibiscus tea is also a refreshing choice, offering further health benefits alongside its antioxidant properties.

Quercetin is a natural part of a healthy lifestyle. Whether you get it through your diet, tea or targeted food supplements, there are plenty of ways to benefit from this versatile compound and support your health in the long term.