6 Health Benefits Of Quercetin

It may help with everything from aging to preventing cancer.

By Emilia Benton

Between all the vitamins and supplements out there, it’s hard to keep up. Besides a multivitamin (and prenatal vitamins if you’re trying to get or are pregnant), you may be curious about what else to add to your wellness routine. One supplement that’s currently trending is quercetin, which is a flavonoid (an antioxidant-rich plant compound) naturally found in the lush pigments of certain foods, like the skin of certain fruits and vegetables. Turns out there is some truth behind the buzz around quercetin benefits.

Quercetin is popular because of how dynamic and versatile it is, including its wide array of benefits. Like other antioxidants, quercetin neutralizes free radicals that damage cell membranes, tamper with DNA, and even cause cell death. It may reduce or even help prevent some of the damage free radicals cause. While more research is needed, it has been studied in humans taking it in supplement form, says Jaclyn Tolentino, DO, a functional medicine physician at Parsley Health in Los Angeles.

This phytochemical is found in many different foods. That include black and green tea, red onions, apples, berries, red wine, leafy green vegetables, tomatoes, cruciferous vegetables (such as broccoli, cabbage, and sprouts), beans, asparagus, peppers, and even cocoa.

It is also available as a supplement in capsule form, as well as as a tincture, powder, gummies, or even IV. Quercetin is also commonly found as a supplement combined with the enzyme bromelain, which is normally found in pineapple, since it synergistically helps increase the absorption and bioavailability of quercetin.

But you definitely don’t want to overdo it, Dr. Tolentino says. “Unfortunately, quercetin is poorly absorbed in the gastrointestinal tract, so you’ll often see it used in higher dosages or the highly recommended phytosome quercetin complex form that has 18 to 20 times increased bioavailability,” she warns.

And bromelain can interfere with blood clotting, so you may not want to take quercetin mixed in with this enzyme if you have a blood clotting disorder.

1. It may lower blood pressure.

2016 meta-analysis in the Journal of the American Heart Association concluded that supplementing with quercetin can potentially bring down blood pressure. But more studies are required to look into how exactly quercetin makes this happen.

Women who supplement with quercetin may see a significant drop in systolic blood pressure in another study. However, more research is needed with humans on different dosing amounts.

2. It can be used for allergy support.

Need a natural alternative to your OTC allergy meds? Quercetin may be it—it prevents immune cells from releasing histamines, which are the chemicals that are responsible for triggering allergic reactions, according to Mount Sinai. Therefore, it may help reduce symptoms of allergies, including runny nose, watery eyes, hives, and swelling of the face and lips.

3. It can regulate your immune system.

You hear talk of a suppressed immune system a lot, but probably not the opposite. But some conditions like rheumatoid arthritis (RA) can cause your immune system to become overly active. Quercetin may be able to suppress it, reducing these inflammatory cytokines (a.k.a. immune cells), especially in the respiratory tract, Dr. Tolentino says.
There are also reports that people with RA who eat an antioxidant-rich diet have less severe symptoms, per Mount Sinai. It’s not clear, though, if that was a direct result of an increased intake of antioxidants.

4. It may protect you from heart disease.

Quercetin may be good for your heart: It may cut down on your risk of developing atherosclerosis, which is a build-up of plaque in the arteries and a major cause of heart attacks and strokes, per research. It may also protect against the damage caused by LDL cholesterol (a.k.a. the bad kind) and prevent death from heart disease, according to Mount Sinai. These effects have only been observed in quercetin taken in from diet, not supplements, though.

5. It may help fight aging.

This nutrient can also clear up senescent cells, which are cells that don’t work but aren’t removed from the body. “A build-up of these cells is associated with aging or age-related disorders,” Dr. Tolentino says.

6. It may prevent certain cancers.

Consuming quercetin may help prevent ovarian cancer, thanks to its anti-inflammation, pro-oxidation, anti-proliferation, and cell cycle arrest mechanisms, according to one study. It and other flavonoids have also been shown to inhibit the growth of cancer cells from breast, colon, prostate, ovarian, endometrial, and lung tumors, according to Mount Sinai. However, more research is needed here as well.

Are there any downsides to taking quercetin?

The good news is that since quercetin is naturally derived from foods, it has a very low side effect profile with minimal overall risks, Dr. Tolentino says. “Some patients may experience intermittent blurry vision, dizziness, or headaches. In high doses given in IV form, a rare occurrence may be kidney damage,” she says.

If you’re considering taking a quercetin supplement in any form, it’s always best to check with your doctor before doing so. “It’s always possible that it can have interactions with other things you may be taking, including medications and supplements,” Dr. Tolentino notes.

The bottom line: Consuming foods containing quercetin can provide a host of health benefits. Supplements have the potential to boost these properties as well, but consult with your doctor first before taking them.


Image: Wanwisa Hernandez, Getty Images