flavonoid

noun

fla·​vo·​noid ˈflā-və-ˌnȯid 

: any of a large group of typically biologically active water-soluble plant compounds (such as the anthocyanins and flavones) that include pigments ranging in color from yellow to red to blue and occur especially in fruits, vegetables, and herbs (such as grapes, citrus fruits, peppers, and dill)

Flavonoids are effective scavengers of free radicals in the test tube (in vitro). However, even with very high flavonoid intakes, plasma and intracellular flavonoid concentrations in humans are likely to be 100 to 1000 times lower than concentrations of other antioxidants …

—Jane Higdon

The rich palette of dyes in butterflies' wings are all derived from chemicals called flavonoids, which the insects cannot make themselves and must sequester from their food plants.

—Nicholas Wade

see bioflavonoid

Examples of flavonoid in a Sentence

Recent Examples on the Web

To analyze the impact of flavonoids on aging in this population, the researchers noted how often people consumed flavonoid-rich foods like tea, apples, oranges, grapefruits, blueberries, strawberries, and red wine. —Sarah Garone, Health, 13 May 2025

The fruit's anthocyanins (antioxidants), flavonoids, and potassium can help lower blood pressure.45 4. —Cristina Mutchler, Verywell Health, 12 May 2025

While tea and wine are the primary sources of flavonoids in Eastern and Western societies, many foods are rich in them, including berries, citrus fruits, apples, onions, and cocoa. —Paul McClure 06, New Atlas, 6 May 2025

Similarly, dark chocolate contains flavonoids that help protect your cells from damage caused by free radicals. —Chelsea Rae Bourgeois, Rdn, Health, 29 Apr. 2025

Word History

Etymology

flavone + -oid

First Known Use

1947, in the meaning defined above

Medical Definition

flavonoid

1 of 2 adjective

fla·​vo·​noid ˈflāv-ə-ˌnȯid  ˈflav- 

: of, relating to, or being a flavonoid

flavonoid

2 of 2 noun

: any of a large group of typically biologically active, water-soluble, plant compounds (such as the flavones) that include pigments ranging in color from yellow to red to blue and occur especially in fruits, vegetables, and herbs (such as grapes, citrus fruits, peppers, and dill)

Tea contains substances called catechins (tea flavonoids) that may protect against heart disease and even cancer.

—UC Berkeley Wellness Newsletter

Flavonoids are effective scavengers of free radicals in the test tube (in vitro). However, even with very high flavonoid intakes, plasma and intracellular flavonoid concentrations in humans are likely to be 100 to 1000 times lower than concentrations of other antioxidants …

—Jane Higdon, An Evidence-Based Approach to Dietary Phytochemicals

Note: Flavonoids are polyphenolic 15-carbon compounds with a basic structure consisting of two benzene rings joined by a chain of 3 carbons.

see bioflavonoid