Flavonoids are compounds that are synthesized by plants and have a common chemical structure. Subclasses of flavonoids include: anthocyanins, flavanols, flavonones, flavones, flavonols, and Isoflavones.
Anthocyanins, such as cyanidin, can be found in bilberry, black currant, blueberry, elderberry, and in red grape and red wine.
Flavanols that are monomers, such as catechin, can be found in green and white teas, apples, grapes, berries, and chocolate. Flavanols that are polymers, such as theaflavins, are found in black and oolong teas, apples, chocolate, and red grapes and red wine.
Flavanones, such as hesperetin, are found in citrus fruits and juices.
Flavones, such as apigenin and luteolin, can found in celery, parsley, hot peppers, and thyme.
Flavonols, such as quercetin, can found in apples, berries, broccoli, kale, scallions, and yellow onions.
Isoflavones, such as daidzein, are found in legumes and soybeans.
Although research continues, flavonoids appear to promote the excretion of potentially toxic or carcinogenic chemicals. They can also aid in DNA repair or in apoptosis (programmed cell death), if cells are irreparable, which is helpful in cancer prevention. In addition, flavonoids can decrease inflammation. Inflammation has been associated with the increased production of free radicals and the inhibition of apoptosis.
Flavonoids also have been associated with decreasing platelet aggregation and can prevent blot clots and cardiovascular disease.