Where do you get quercetin naturally? Exploring the Best Food Sources

November 1, 2025 •

4 min read

Quercetin is the most abundant dietary flavonoid, with research linking its intake to numerous health benefits, including reduced inflammation. Incorporating a variety of quercetin-rich foods is the most natural way to boost your intake, and fortunately, many common fruits and vegetables pack a powerful punch.

Quick Summary

An in-depth look at the highest food sources of quercetin, detailing key fruits, vegetables, and drinks. Provides tips on food preparation and natural pairings to maximize your body's absorption of this powerful antioxidant.

Key Points

Capers are the richest source: Raw capers contain the most concentrated levels of naturally occurring quercetin.
Focus on colored plants: Red onions, berries, red grapes, and dark leafy greens are excellent natural sources of this flavonoid.
Eat the skin: Much of the quercetin in fruits like apples is concentrated in the peel; avoid over-peeling to maximize intake.
Prepare with care: Avoid boiling, as it leaches quercetin into the water. Opt for raw, steamed, or lightly fried preparations.
Pair with fat or vitamin C: For better absorption, eat quercetin-rich foods alongside healthy fats like olive oil or with sources of vitamin C.
Variety is key: A diverse diet rich in colorful fruits and vegetables ensures you get a broader range of nutrients, including a healthy dose of quercetin.

What is Quercetin?

Quercetin is a plant-derived pigment (flavonoid) known for its potent antioxidant and anti-inflammatory properties. As one of the most widely distributed and extensively studied flavonoids, it helps neutralize free radicals, which cause cellular damage and are linked to various chronic diseases, including heart disease and cancer. While available as a dietary supplement, obtaining quercetin naturally through whole foods provides a synergistic boost from other vitamins, minerals, and phytochemicals. It is important to know which foods to focus on and how to prepare them to maximize your intake effectively.

Top Natural Sources of Quercetin

Quercetin is found in the skins, leaves, and outer layers of many plants, which is why color often indicates a high flavonoid content. The concentration can vary depending on factors like growing conditions and ripeness. Some of the most notable food sources include:

Capers: Raw capers are arguably the most concentrated natural source of quercetin, providing a significant amount per 100 grams. Even canned capers retain a high concentration.
Onions: Red and yellow onions are particularly rich in quercetin, with the highest concentration found in the outer, edible rings closest to the skin. Shallots are also an excellent source.
Apples: Especially red apples, contain quercetin primarily in the skin. Eating the apple with its skin is key to maximizing your intake.
Berries: A variety of berries, including blueberries, cranberries, and bilberries, are great sources.
Leafy Greens: Kale, spinach, and red leaf lettuce contain appreciable levels of quercetin.
Grapes and Red Wine: The quercetin in grapes is concentrated in the skins, and this is why red wine is a source of this flavonoid.
Broccoli: This cruciferous vegetable contains quercetin, though the amount is lower than in some other top sources.
Peppers: Yellow and green bell peppers are noted for their quercetin content.
Tea: Both green and black tea are sources, though the brewing process can affect the final amount.

Maximizing Quercetin from Your Diet

While simply eating these foods is beneficial, optimizing preparation and pairings can significantly increase the amount your body absorbs. Bioavailability, or the degree to which your body can absorb a nutrient, is a key consideration for quercetin.

How to Prepare Your Foods for Best Results

Mindful Cooking: Cooking methods impact quercetin content. Boiling, especially for long periods, can cause the water-soluble flavonoid to leach out into the water. Light cooking methods like steaming, stir-frying, or microwaving without excess water can be better for retention. Baking and grilling can also effectively maintain—or even increase—quercetin levels in some foods by breaking down plant cell structures.
Raw Consumption: For foods that can be eaten raw, such as red onions, bell peppers, and certain berries, this is often the best way to get the maximum amount of quercetin. Consider adding finely sliced red onions or fresh berries to salads to preserve their content.
Don't Over-Peel: Since much of the quercetin in foods like onions and apples is concentrated in the outer layers and skin, avoid over-peeling to prevent nutrient loss.

Pairing for Enhanced Absorption

Because quercetin has naturally low bioavailability, pairing it with other compounds can boost absorption.

Healthy Fats: Consuming quercetin-rich foods with healthy fats, like those found in olive oil or avocados, can increase its absorption. Drizzling olive oil over a salad with red onions and berries is a delicious way to do this.
Vitamin C: Pairing quercetin with vitamin C-rich foods has a synergistic effect, potentially amplifying its antioxidant benefits. Add citrus fruits to a green tea or pair berries with bell peppers.
Bromelain: This digestive enzyme, found naturally in pineapple, is often combined with quercetin in supplements to enhance absorption. While less practical for food pairings, it’s a good supplement synergy to be aware of.

Comparison of Cooking Methods on Quercetin Levels

Different cooking methods can dramatically influence the final quercetin content of a food. This table highlights how varying techniques affect quercetin in some common dietary sources.


Food (example)	Raw Quercetin Level (relative)	Boiling Effect	Frying/Baking Effect	Steaming Effect	Best Practice
Red Onions	High	Significant loss (up to 50-60%) due to leaching	Potential increase due to cell wall breakdown	Moderate retention	Eat raw or lightly sauté
Broccoli	Moderate	Significant loss into water	Moderate to good retention	Good retention	Lightly steam or eat raw
Apples (with skin)	High	Not applicable	Baking retains quercetin, especially in skin	Not applicable	Eat raw with skin

Conclusion

For anyone looking to reap the anti-inflammatory and antioxidant benefits of quercetin, the good news is that this powerful flavonoid is naturally available in a wide variety of delicious and accessible foods. The best strategy involves incorporating a diverse mix of these natural sources into your diet, focusing on raw or lightly cooked preparations where possible. The highest concentrations are often found in capers, red onions, and leafy greens, but a mix of berries, apples, and peppers will also significantly contribute to your intake. Furthermore, by pairing these foods with healthy fats or vitamin C, you can improve your body's ability to absorb and utilize quercetin's beneficial properties. Prioritizing whole foods over supplements ensures you receive a host of other beneficial nutrients that work synergistically for optimal health. By being mindful of your food choices and preparation, you can easily ensure your diet is rich in this valuable plant pigment. For more nutritional information on flavonoids, consult reputable sources such as the National Institutes of Health.

: https://www.mskcc.org/cancer-care/integrative-medicine/herbs/quercetin

Frequently Asked Questions

Raw capers are the food with the highest concentration of quercetin. Other top food sources include red onions, kale, and varieties of berries and apples.

Cooking does not completely destroy quercetin, but the method matters. Boiling can cause significant loss as the compound leaches into the water. Light steaming, baking, or frying can help retain or even increase quercetin levels in some foods by breaking down cell walls.

Quercetin from food is often more bioavailable than from supplements, especially when combined with other compounds naturally present in the food. However, supplemental forms often include other ingredients like bromelain or vitamin C to enhance absorption.

The best natural approach is to eat a variety of quercetin-rich fruits and vegetables daily. For maximum benefit, eat foods like capers and red onions raw or lightly cooked, and consume apples with the skin on.

Some studies suggest organically grown produce, such as tomatoes, can have a higher quercetin content compared to conventionally grown counterparts. However, this can also vary depending on the specific plant species.

Red and yellow onions contain the most quercetin. The highest concentration is found in the outermost edible rings closest to the papery skin, so peel off as little as possible.

Yes, you can increase absorption by pairing quercetin-rich foods with healthy fats (like olive oil) or foods high in vitamin C (like citrus or bell peppers).