Bioflavonoids, also called flavonoids, are a group of plant-based compounds that may be good for human health.

There are approximately 6,000 different varieties of bioflavonoids known. Some are used in medications, supplements, and for other health purposes (1).

Bioflavonoids are found in citrus fruit peels, tea leaves, wine, and many types of produce. They contribute to the colors of fruits, vegetables, herbs, and medicinal plants (1).

These compounds have strong antioxidant and anti-inflammatory effects. They may help protect your heart, aid your body with allergies and viruses, and reduce your risk for cancer and other diseases.

Summary

Bioflavonoids are found in a variety of fruits and vegetables. They may benefit human health, from protecting the heart to reducing the risk of certain diseases.

Bioflavonoids may help improve your health. They have the potential to both treat and help prevent a variety of conditions.

One way bioflavonoids take action against disease is through their antioxidant activity. They may protect against free radicals, which can damage your cells and contribute to different health issues (2).

Bioflavonoids also have anti-inflammatory properties. Reducing inflammation in the body may help reduce tissue injury and counter diseases like diabetes, asthma, and cancer (1, 3).

Researchers are still exploring:

  • the benefits of different groups of bioflavonoids
  • how they work
  • how they might be used to benefit people’s health
Summary

Bioflavonoids have antioxidant and anti-inflammatory properties that may aid your body in a variety of diseases. Research is still being done on their benefits and how they work.

With their strong antioxidant activity, bioflavonoids help counter molecules called free radicals.

At low levels, free radicals help fight bacteria and viruses. When your body produces too many free radicals, though, they can cause a reaction called oxidative stress that damages your cells (2, 4).

Bioflavonoids may work by scavenging free radicals, meaning they deactivate these molecules to keep them from harming cells. They may also interfere with the enzymes involved with the formation of reactive oxygen species (ROS), a type of free radical.

Bioflavonoids with particularly high antioxidant activity are found in:

By reducing damage from oxidative stress, antioxidants may help slow the aging process and prevent diseases like cancer and cardiovascular disease.

Summary

Bioflavonoids have high antioxidant activity that counters free radicals to help keep your cells healthy. This activity may also slow the aging process and help prevent certain diseases.

Several allergic diseases may respond well to bioflavonoids (5, 6). These include:

In addition, flavonoids may block mast cells and basophils, which both contribute to allergic reactions (5). Certain flavonoids may also reduce the activity of cytokines, which are proteins that play a role in asthma (10).

Development of allergic conditions like atopic dermatitis and asthma may be associated with oxidative stress (7, 8). Flavonoids may help by scavenging free radicals and reducing damage to cells (9).

Researchers are still trying to determine exactly how bioflavonoids work. They also need to know how much may be effective in preventing or treating these diseases. More research, especially in people, is needed.

Summary

Bioflavonoids may improve allergic conditions like atopic dermatitis and asthma by blocking compounds that cause allergic reactions. However, more studies need to be done.

Bioflavonoids’ antioxidant and anti-inflammatory characteristics may also have benefits for cardiovascular disease.

Research indicates that eating more flavonoids may be associated with a lower risk of death from cardiovascular disease (11, 12).

Other research suggests that consuming certain subgroups of bioflavonoids is more likely to lower your risk for developing cardiovascular disease.

One subgroup, flavonols, may also reduce the risk of stroke, though research results are inconsistent (13, 14).

Further studies are needed to determine the amount of the compound that gives the most benefit and to discover the precise role of bioflavonoids for heart health.

Summary

Eating foods rich in bioflavonoids may lower your risk for cardiovascular disease and stroke. However, more research needs to be completed.

Bioflavonoids may have beneficial effects on the nervous system, including improving memory and helping treat neurological diseases. They may also help increase blood flow to the brain and improve brain function (15).

It’s still unclear how bioflavonoids produce these effects. Some research suggests that bioflavonoids may help protect nerve cells from damage (16).

Bioflavonoids may also impact astrocytes, which are cells in the central nervous system that play a role in forming and maintaining synapses to transmit cell signals (16).

One study in healthy adults ages 50 to 69 years found that eating a diet high in cocoa flavanols for 3 months enhanced the function of the dentate gyrus. This region in the brain may be related to memory issues in older adults (17).

Research indicates that bioflavonoids may also help prevent or delay Alzheimer’s disease and maintain cognitive abilities (18, 19, 20).

Additional human studies are needed to understand the mechanisms at work and to explore potential treatments.

Summary

Bioflavonoids may help improve memory and prevent or treat diseases like Alzheimer’s. More studies in people are needed to confirm bioflavonoids’ effectiveness and investigate possible treatment options.

Bioflavonoids may have additional benefits, including:

Recent research has indicated that eating around 500 mg of flavonoids per day may reduce the risk of death from cancer (21).

A review of studies also suggested that specific flavonoids in the diet may lower the risk of breast, prostate, and other types of cancers (22, 23). Still, some controversy remains, and more research is needed.

Bioflavonoids may also help manage cholesterol. According to one study in rats, the flavonoids luteolin and quercetin may lower high levels of blood cholesterol (24).

Other research found that eating anthocyanins, a type of flavonoid, may improve the function of HDL (good) cholesterol in reducing excess cholesterol in the body (25).

Still, the researchers noted that studies done in cell models may not show the same results in people, and more research should be done.

Bioflavonoids show some anti-viral properties, too. Research indicates that flavonoids may help combat hepatitis B, Japanese encephalitis, and several influenza (flu) viruses, among others (26, 27).

Some studies have explored flavonoids’ potential to help treat coronavirus infections, including COVID-19 (28, 29). However, there’s still not enough research in this area.

It’s important to note that many studies on bioflavonoids have been done in vitro, or outside of the body (30). Overall, more studies need to be completed in humans to confirm the health benefits of bioflavonoids.

Summary

Bioflavonoids may have additional benefits for health, including anti-cancer, cholesterol reducing, and anti-viral properties. Still, research is inconsistent, and more studies need to be done, particularly in people.

Research estimates that adults in the United States generally consume around 200 mg of bioflavonoids each day (31). The study found that the bioflavonoids primarily came from tea, but that berries and wine as a source had also increased.

You may find many bioflavonoid-rich foods in your refrigerator or pantry. Food sources of bioflavonoids include:

  • apples
  • grapes
  • strawberries
  • blueberries
  • cherries
  • bananas
  • peaches
  • lemons
  • celery
  • red peppers
  • kale
  • onions
  • tomatoes
  • lettuce
  • mint
  • parsley
  • soybeans
  • sweet potatoes
  • green and black tea
  • red wine
  • chocolate

Bioflavonoids are available as supplements, too. When reading labels, it’s helpful to know that bioflavonoids are divided into several subcategories. The main ones include:

  • flavonols: quercetin, kaempferol, myricetin, and rutin
  • isoflavonoids: genistein and daidzein
  • flavones: apigenin and luteolin
  • flavanones: hesperitin, naringenin, and eriodictyol
  • anthocyanins: cyanidin, delphinidin, malvidin, and peonidin

Supplements are an option if you’re interested in consuming more or specific bioflavonoids, though many people may already get enough from their diet.

It’s important to talk with a healthcare professional if you’re thinking of taking a new supplement.

Currently, there is no Dietary Reference Intake (DRI) suggestion for flavonoids from the National Academy of Sciences (32).

The United States Department of Agriculture’s 2020–2025 Dietary Guidelines for Americans suggest eating a variety of fruits, vegetables, and whole grains (33).

Summary

U.S. adults consume around 200 mg of bioflavonoids daily. You can get bioflavonoids from supplements or from many fruits, vegetables, teas, and other foods.

Fruits and vegetables have high concentrations of bioflavonoids and a relatively low risk of side effects. The safest and healthiest way to access bioflavonoids is through your diet (34).

More research is needed on the safety of supplements, particularly since they may contain much higher concentrations of bioflavonoids compared to foods.

It’s also still unclear whether taking different bioflavonoid supplements at once or taking supplements long term could cause interactions or side effects (34, 35, 36).

It’s always a good idea to speak with a healthcare professional before starting any new supplements, especially if you’re pregnant. Also, some supplements may interact with certain medications.

Summary

There’s a low chance of side effects if you consume bioflavonoids through your diet. However, more research is needed on the safety, interactions, and possible side effects of supplements.

Bioflavonoids may help improve health conditions from allergies and cardiovascular disease to Alzheimer’s disease and cancer.

Still, more studies need to be done involving people to confirm the benefits and explore possible treatments.

Bioflavonoids are part of a nutrient-dense balanced diet that includes a variety of fruits and vegetables. They’re also available as supplements. As with any supplement, talk with a healthcare professional before taking them.