What is flavonoid?

Flavonoids constitute a large class of phytochemicals that are widely distributed in the plant kingdom, are present in high concentrations in the epidermis of leaves and skin of fruit, and have important and varied roles as secondary plant metabolites.

The major sources of flavonoid intake were found to be in tea, inions and apples. Catechin, tannin and quercetin are among the flavonoid available in tea. They act as antioxidant.

Catechin
*May stimulate detoxication enzymes and protects liver
*Strengthen capillaries.
*Block inflammation.
*May inhibit tumor formation

Quercetin and tannin
*May stimulate detoxication enzymes
*Strengthen capillaries.
*Block inflammation.
*May inhibit tumor formation

Several studies have shown that people who have a high intake of plant flavonoids are less likely to die from heart disease or develop some cancers or other chronic diseases.

Although many thousands of different flavonoids exist, they can be classified into a few different subclasses. The main subclasses that are important from a human health perspective are the flavones, flavanones, flavan-3-ols, flavanones, anthocyanins and isoflavones.

High intakes seem to protect against stroke. Researches involved in a 1996 Dutch study assessed the diets of 552 men aged 50 to 69 years in 197 and followed them up for 15 years.

The results showed that those with the highest intakes of dietary flavonoids (mainly quercetin) had around 75 per cent less risk of stroke compare to those with the lowest intakes. Black tea contributed about 7 percent o the flavonoid intake in the study.
What is flavonoid?