Firstly, they're easy to come by! There are more than 4,000 flavonoids, each one a plant pigment with recognised antioxidant properties. Once referred to as vitamin P, they're natural compounds that belong to the polyphenol family. They give fruits, vegetables and medicinal plants their colour. There are two kinds of flavonoids: insoluble 'tannins' that capture iron and protect against some cancers and soluble variants that are absorbed by the body and provide an antioxidant action.
They are all powerful antioxidants. In other words they protect cells against damage from free radicals, the infamous unstable oxygen molecules that, when produced in excess, damage our skin cells. The direct consequence of free radicals is defective cellular function and subsequent premature ageing of the skin. Flavonoids limit this oxidative damage. And that's not all! Antioxidants strengthen blood vessels, improve circulation, protect against cardiovascular disease, as well as providing anti-inflammatory and antispasmodic properties.
Flavonoids are found in a host of fruits and vegetables alongside most medicinal plants. The best known are: quercetin found in onions, apples and buckwheat, rutin and hesperidin present in orange, grapefruit and other citrus fruits, polyphenols in pine bark, grape seed, green tea and red wine, anthocyanin in blueberries or bilberries and, finally, genistein in soy. Flavonoids are also available as dietary supplements, but a diet rich in fresh fruits and vegetables will, nonetheless, provide you with a decent supply!