Flavonoids are a class of
water-soluble plant
pigments, that, while not
essential nutrients, have been shown to have beneficial actions on the
heart and other bodily systems.
Flavonoids all show a similar
chemical construction including two
benzene rings that lie on either side of a 3-
carbon ring. The various classes of flavonoids are created by multiple combinations of
hydroxyl groups,
sugars,
oxygens, and
methyl groups that attach to the common structure. The classes are made up of
flavanols,
flavanones,
flavones,
flavan-3-ols (
catechins),
anthocyanins, and
isoflavones.
Due to the
chemical structure of these substances, many flavoniods, when present in the body, are extremely
antioxidant. They combine easily with
free radicals in the body such as
hydroxyl radicals,
superoxide anions, and
lipid peroxy radicals. These radicals are often
antagonists to certain diseases,
cellular and
chromosomal damage, and
aging, and therefore, the presence of flavoniods counteracts the damage done by these chemicals.
Flavonoids are found in all plants to some degree, and are major contributors to the actions of some
herbal medications. They are purported by many
herbalists to have
antibacterial,
anti-inflammatory,
antiallergic,
antimutagenic,
antiviral,
antineoplastic,
anti-thrombotic, and
vasodilatory actions.
While not all the claims associated with these chemicals are proven, studies have shown that certain flavonoids do, in fact, have medicinal properties. For example, the
quercetin in
onions have been shown to protect the heart from damage and disease. An
inverse relationship between flavonoid intake and
coronary disease has been shown to exist.
Some potent sources of flavonoids include
green tea,
black tea,
soy beans,
citrus fruits,
wine, and colored berries.