What does quercetin mean? What to Eat, How Much to Take, and Any Side Effects

Quercetin might be good for your health because it can lower your risk of getting some diseases and reduce inflammation.

 

Quercetin is a natural pigment present in many:

fruits vegetables grains
It’s one of the best foods for getting antioxidants, and it helps your body fight free radical damage, which is linked to many chronic diseases.

In addition, the antioxidants in it may help lower:

 

inflammation
allergy symptoms
blood pressure

 

What does quercetin mean?
Quercetin is a pigment that belongs to a group of plant compounds called flavonoids.

Flavonoids can be found in

vegetables
fruits
grains
tea

They may be good for your health in a number of ways, such as lowering your risk of heart disease, cancer, and brain diseases that get worse over time.

The good things that flavonoids like quercetin do for your body come from their ability to work as antioxidants.

Antioxidants are chemicals that can bind to free radicals and get rid of them.

When there are too many free radicals in the body, they can damage cells because they are fragile.

A lot of long-term diseases, like cancer, heart disease, and diabetes, have been linked to damage done by free radicals.

The flavonoid that is found most often in food is quercetin. It is thought that the average person gets 10–100 mg of it every day from different foods.

Onions, apples, grapes, berries, broccoli, citrus fruits, cherries, green tea, coffee, red wine, and capers are all foods that often have quercetin in them.

It can also be bought as a supplement in the form of powder or capsules.

People take this vitamin for a number of reasons, such as:

boost immunity
fight inflammation
combat allergies
aid exercise performance
maintain general health

 

 

 

Health benefits of quercetin
Researchers have found a number of possible health effects linked to quercetin’s antioxidant properties.

Here are some of the best ones that are backed by science.

May reduce inflammation
Free radicals might hurt your cells, but they might also do other things.

High amounts of free radicals may help turn on genes that make inflammation worse, according to research. So, having a lot of free radicals may make the inflammatory reaction stronger.

Some inflammation is needed for your body to heal and fight off infections, but long-term inflammation is linked to health problems like heart and kidney diseases, some types of cancer, and more.

There are studies that show quercetin may help lower inflammation.

In test-tube tests, quercetin lowered levels of molecules that show inflammation in human cells. These molecules included interleukin-6 (IL-6) and tumor necrosis factor alpha (TNFα).

An 8-week study with 50 women who had rheumatoid arthritis found that those who took 500 mg of quercetin had much less stiffness in the morning, morning pain, and pain after exercise.

Also, inflammation markers like TNFα were lower in them than in the people who got a placebo.

Even though these results are encouraging, more study with humans is needed to fully understand the compound’s possible anti-inflammatory effects.

May ease allergy symptoms
Because quercetin may help reduce inflammation, it may help with allergy symptoms.

Studies in test tubes and on animals showed that it may stop enzymes that cause inflammation and chemicals that make inflammation worse, like histamine.

For instance, one study found that giving mice quercetin supplements lowered their anaphylactic response to peanuts.

Still, it’s not clear if the compound works the same way on human allergies, so more study is needed before it can be suggested as an alternative treatment.

 

 

 

May have anticancer effects
Additionally, quercetin may help fight cancer because it is an antioxidant.

A review of studies done in test tubes and on animals showed that quercetin stopped prostate cancer cells from growing and caused them to die.

The compound had the same effects on cancer cells from the liver, lungs, breast, bladder, blood, colon, ovarian, lymphoid, and adrenal glands as it did in test tubes and animals.

Even though these results look good, more research with real people is needed before quercetin can be suggested as an alternative way to treat cancer.

May lower your risk of chronic brain disorders
According to research, quercetin’s antioxidant qualities may help protect against brain diseases that get worse over time, like Alzheimer’s and dementia.

Mice with Alzheimer’s disease were injected with quercetin every two days for three months in one study.

By the end of the study, the shots had gotten rid of several signs of Alzheimer’s, and the mice did much better on tests of their ability to learn.

In a different study, a meal high in quercetin lowered signs of Alzheimer’s disease and made the brains of mice in the early to middle stages of the disease work better.

But the food didn’t change much or anything at all in animals with middle to late-stage Alzheimer’s.

People who drink coffee may have a lower chance of getting Alzheimer’s disease.

Instead, study indicates that quercetin, not caffeine, is the main chemical in coffee that may help protect against this illness.

Even though these results look good, more study needs to be done on humans.

May reduce blood pressure
One in three American people has high blood pressure. It makes you more likely to get heart disease, which is the main cause of death in the US.

According to some studies, quercetin may help lower blood pressure. In studies done in test tubes, the substance seemed to make blood vessels relax.

Mice with high blood pressure were given quercetin every day for 5 weeks. The upper and lower numbers of their systolic blood pressure dropped by an average of 18% and 23%, respectively.

A review of 9 studies involving 580 people also found that taking more than 500 mg of quercetin every day lowered peak blood pressure by 5.8 mm Hg and diastolic blood pressure by 2.6 mm Hg.

Even though these results are encouraging, more research with humans is needed to see if the substance could be used as an alternative treatment for high blood pressure.

 

 

 

Other potential benefits
Here are some more possible perks of quercetin:

Could help fight age. Researchers using test tubes and animals have found that quercetin may help renew or get rid of cells that are showing signs of aging and lower signs of aging. But more study on people is needed.

 

Could help with training. Looking at 11 studies with people, it was found that quercetin may slightly improve ability in endurance sports.

 

Could help keep blood sugar in check. Studies on both people and animals show that the compound may lower fasting blood sugar levels and protect against diabetes problems.

 

 

Food sources and dosage
Quercetin is naturally found in a lot of plant-based foods, mostly in the peel or top layer.

Good food sources include:

capers
peppers — yellow and green
onions — red and white
shallots
asparagus — cooked
cherries
tomatoes
red apples
red grapes
broccoli
kale
red leaf lettuce
berries — all types, such as cranberries, blueberries, and raspberries
tea — green and black
Keep in mind that the amount of quercetin in food may change based on how it was grown.

As an example, one study found that tomatoes grown organically had up to 79% more quercetin than tomatoes grown in other ways.

But other tests show that the amount of quercetin in different types of tomatoes is different, even if they were grown in the same way. There was no difference between bell peppers that were grown normally or organically.

Quercetin supplements
As a dietary supplement, quercetin can be bought online and in health food shops. It comes in a number of different forms, such as pills and powders.

Most people take between 500 mg and 1,000 mg per day.

When taken by itself, quercetin is not bioavailable, which means that your body does not absorb it well.

That’s why the pills might have extra ingredients like vitamin C or digestive enzymes like bromelain, which may help the body absorb the nutrients better.

Additionally, some studies show that quercetin works better when mixed with other flavonoid products, like resveratrol, genistein, and catechins.

 

 

 

 

Safety and side effects
Quercetin is safe to eat and can be found in many fruits and veggies.

It seems to be generally safe to take as a vitamin, with few to no side effects.

Taking more than 1,000 mg of quercetin every day might lead to mild side effects like headaches, stomachaches, or dizziness.

Quercetin is safe for pregnant and nursing women to eat when it is in food.

But there aren’t many studies that look at how safe quercetin pills are for women who are pregnant or breastfeeding, so if you are one of those women, you shouldn’t take quercetin.

Before taking quercetin or any other supplement, you should talk to your doctor because it can combine with some medicines, like blood pressure and antibiotics.

 

 

The bottom line
The most common flavonoid found in food is quercetin.

It has been linked to better exercise ability and lower levels of sugar, inflammation, and blood pressure. It may also protect the brain, help with allergies, and fight cancer.

More study on humans is needed, even though its benefits look good.