Bioflavonoids, or flavonoids, are a subclass of plant polyphenols. More than 6,000 bioflavonoids have been identified to date, with many being bioavailable and bioactive. They have been reported to have vasodilating actions, as well as antioxidant, anti-allergenic, anti-inflammatory and antiviral properties. Bioflavonoids provide much of the color, flavor and aroma for many foods and are found in fruits and vegetables, tea, red wine, cacao and some nuts. According to the USDA's Agricultural Research Service, consuming bioflavonoids has been linked to a decreased risk of heart disease in some studies. Bioflavonoids are classified into six groups: anthocyanidins, flavan-3-ols, flavonones, flavones, flavonols and isoflavones.
Anthocyanidins
Common anthocyanidins include cyanidin, delphinidin, malvidin, pelargonidin, peonidin and petunidin. Anthocyanidins are found in fruits such as apples, berries, currants, eggplant, grapes, pears and plums; in vegetables such as cabbage, radishes and red onions; in nuts such as hazelnuts, pecans and pistachios; and in red wine.
Flavan-3-ols
Common flavan-3-ols include catechins, epicatechins, theaflavins and thearubigins. Flavan-3-ols are found in fruits such as apples, apricots, berries, cherries, grapes, nectarines, peaches, pears and plums; in Swiss chard; in nuts such as almonds, cashews, hazelnuts, pecans and pistachios, in green, black and oolong teas; in cacao; and in red and white wine.
Flavonones
Common flavonones include eriodictyol, hesperetin and naringenin. Flavonones are found in citrus fruits such as kumquats, lemons, limes, grapefruits, oranges and tangerines; in artichokes; and in red and white wine.
Flavones
Common flavones include apigenin and luteolin. Flavones are found in fruits such as peppers and olives; in vegetables such as artichokes, celery, onions and parsley; and in green tea.
Flavonols
Common flavonols include isorhamnetin, kaempferol, myricetin and quercetin. Flavonols are found in fruits such as apples, apricots, blueberries and blackberries; in vegetables such as arugula and asparagus; in green and oolong tea; in cocoa; and in red wine.
Isoflavones
Common isoflavones include genestein and daidzein. Isoflavones are found in soybeans and in smaller amounts in pistachios.
Warnings
A study published in the August 2000 issue of Free Radical Biology and Medicine, warns that excessive flavonoid intake may have toxic effects. The researchers recommend that caution be used in consuming flavonoids at higher levels, such as through supplements, than would be obtained from a standard vegetarian diet.
This information is for nutritional education only. Please consult your health-care provider for any medically related concerns.
