Do Red Onions Have Quercetin? (EXPLAINED)

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Does red onions have Quercetin?

Red onions are higher in antioxidant content than any other type of onion. They are also loaded with prebiotics that helps you maintain a healthy gut. If those aren’t enough reasons to add them to your diet, consider red onions are a culinary staple that you can use to liven up the flavor of a wide range of dishes or enjoy in salads. Still, our question today is, do red onions have quercetin.

Quick Answer: Yes – Red onions do contain quercetin. Compared to other similar foods, their quercetin content is high.

Quercetin Content of Red Onions

Red onions contain 31.77mg/100g of Flavonol quercetin and are also a rich source of manganese, vitamins B6 and C, and copper.

Are Red Onions High in Quercetin?

Compared to other foods, red onions are very high in quercetin.

Let’s take a look at how they compare to 5 similar foods.

  • Though closely related to red onions, white onions provide far less quercetin, 8.06mg/100g versus 31.77.
  • Garlic only supplies 1.74mg/100g of quercetin, a fraction of what red onions provide.
  • With only 0.23mg/100g, a fennel bulb’s quercetin content is minute compared to red onions.
  • Spring onions or scallions are considered high in quercetin with 10.68mg/100g but come nowhere close to red onions.
  • Chili peppers provide a respectable14.7mg/100g of quercetin, but that is still less than half what red onions offer.


USDA Database for the Flavonoid Content of Selected Foods: 

WebMD “Health Benefits of Red Onion”: