Getting to Know Quercetin: A Natural Way to Support Balance in the Body
Let’s say you’re at the farmers’ market, taking in the wide array of fresh produce. Which fruit or vegetable offers the best nutrition? The answer to that depends on which nutrients you’re searching for, but when it comes to quercetin, two of the best options would be a crisp, red apple or a fragrant yellow onion. Nutrition should be delicious, after all!
Quercetin (pronounced kwur-suh-tin) isn’t flashy. It doesn’t come with a buzzword or make big promises. But this natural compound is found in many fruits, vegetables and even a cup of tea, and it plays a meaningful role in keeping the body steady and resilient.
Let’s talk about what makes quercetin worth knowing—what it is, where it’s found, how it works and why it might be worth inviting into your daily routine.
What Is Quercetin and Where Does It Come From?
Quercetin is a plant pigment—a type of flavonoid—that helps plants defend themselves from stress, sun, and pathogens. Think of it as a built-in shield that fruits and vegetables use to stay strong. And when we eat those foods, we get some of the health benefits of that shielding power too.
Quercetin works in the body as an antioxidant, meaning it helps neutralize free radicals. Those are unstable molecules that build up from normal processes like metabolism, as well as outside stressors like pollution or poor diet. Over time, too many of them can lead to oxidative stress, which has been linked to aging at the cellular level.1
The good news: quercetin helps keep that cycle in check.
Quercetin Foods You Already Know and Love
If you eat a colorful diet full of plants, you’re probably already getting the benefits of quercetin without thinking about it. But some food sources have higher quercetin content than others.
Onions, especially red and yellow ones, are among the highest food sources of quercetin. In fact, one raw onion can have up to 50 mg of quercetin, depending on size and variety.2 Apples, particularly with the skin, are another excellent source. So are cranberries, capers, leafy greens and green or black tea.
Even coffee and red wine have small amounts. So, yes, your morning cup of joe or evening glass of cabernet might have a little quercetin in there, too.
You can also explore foods high in quercetin through recipes and whole-food-based routines, adding it to more foods you already eat.
How Cooking Affects Quercetin
Heat does change the effects of quercetin, but not always for the worse. Cooking can reduce the total amount in quercetin-rich foods like onions, but it can also make it easier for your body to absorb the quercetin that’s left behind.3 Light steaming tends to preserve more than boiling or deep-frying, so how you cook matters.
That said, raw or lightly cooked is usually your best bet if you’re looking to get the highest amount of quercetin from your vegetables.
What About Quercetin Supplements?
For some people, getting enough quercetin from food alone can be a bit of a stretch, especially if you’re managing seasonal issues, stressed out or just want extra antioxidant support. That’s where supplements come in.
Quercetin supplements typically provide a concentrated dose, often between 250 to 1,000 mg per capsule. Some formulas include extra ingredients to help with absorption, like vitamin C or bromelain (an enzyme found in pineapple that may help quercetin get into your system more efficiently4).
If you’re browsing, Swanson’s quercetin collection includes several options blended with complementary nutrients to support bioavailability.
How Quercetin Supports Balance in the Body
Quercetin is best known for its antioxidant properties, but it also has other helpful roles in the body.
It’s been studied for its potential benefits to help maintain a healthy respiratory response and support the immune system, especially during seasonal changes.5 Some people find it helpful during spring or fall when natural shifts cause challenges.
There’s also growing interest in how quercetin may support the gut barrier and help regulate immune responses. While preliminary research in animals looks promising, further study in humans is needed.6
In short, it’s not just about protecting cells. Quercetin may help your body stay in balance when things start to tilt.
Who Might Want to Be Cautious
Quercetin is generally safe for most people when used as directed. But high doses may interact with certain medications, including antibiotics or blood thinners. It’s always a good idea to check in with your healthcare provider if you’re adding new dietary supplements, especially if you’re already taking others or managing a health condition.
Pregnant or breastfeeding women should also talk with their doctor first, as research in those areas is still limited.
Quercetin’s Friends in the Supplement World
Quercetin may pair well with other antioxidants and nutrients for complementary benefits. For instance, CoQ10 is another powerful antioxidant that supports energy production and cellular defense. Similarly, astaxanthin—a lesser-known antioxidant—can support eye health and more. Read all about it in Astaxanthin Eye Health Benefits: A Powerful Antioxidant.
For a thoughtful daily routine, you might consider combining quercetin with a magnesium-rich diet (learn more in Magnesium-Rich Foods to Add to Your Diet), healthy fats and other phytonutrient-rich foods. Other options could include NAC or bromelain for added respiratory support. It’s less about one superstar and more about how each player’s talents contribute to a win.
The Bottom Line on Quercetin
At the end of the day, quercetin is one of those quiet, but steady, nutrients that makes your system more resilient. It’s in your blueberries, your red onions and even your green tea. And maybe, if you choose, in a small daily capsule.
When you’re looking for that extra boost in antioxidant support, immune health and respiratory wellness, quercetin is there to help!
You be well, now.
Swanson
*These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.
Sources
1. Rahal A, et al. Biomed Res Int. 2014; 2014: 761264. Read source
2. Dabeek WM, Marra MV. Nutrients. 2019 Sep 25;11(10):2288. Read source
3. Németh K, Takàcsova M, Piskuła MK. Pol J Food Nutr Sci (2003): 170-174. Read source
4. Colunga Biancatelli RML, et al. Front Immunol. 2020 Jun 19; 11: 1451. Read source
5. Heinz SA, et al. Pharmacol Res. 2010 Sep;62(3):237-42. Read source
6. Li B, et al. Front Pharmacol. 2024 Mar 26;15: 1362464. Read source
