Wednesday, March 20, 2013
Article # 410. Flavonoids
Flavonoids are phytonutrients in plant-based food products that often contribute to the color of the foods. They provide antioxidant activity which may play a significant role in cardiovascular health and may help to prevent against diseases such as cancer caused by free-radical damage. They may also provide benefit in the prevention of other chronic conditions such as osteoporosis and diabetes. Certain plant-based food groups are known to be much higher in flavonoids than others including some fruits, vegetables, spices and grains.
Flavonoids have several subcategories. Each type of flavonoid has a different chemical structure, and different forms are in various food sources. The six families of flavonoids are anthocyanidins, flavonols, flavanones, flavanols (including catechins and proanthocyanidins), flavones and isoflavones. Flavanols are a very large family of flavonoids, and include catechins, proanthocyanidins, theaflavins and thearubigins. Isoflavones are the most easily absorbed by the body, whereas anthocyanins and flavanols are less bioavailable.
Flavonoids receive promotion for a variety of health benefits. At the time of publication, there is research into their possible role in preventing cancer and heart disease, according to the American Cancer Society. Isoflavones, for example, might help to prevent prostate and breast cancer due to their ability to influence estrogen and other hormone levels. Flavonoids are also antioxidants, meaning they can rid the body of potentially harmful substances called free radicals. This protective benefit may prevent chronic disease and minimize the effects of aging.
Flavonoids are in a wide variety of plant sources. The Linus Pauling Institute provides a comprehensive list of flavonoids and their corresponding food sources. Red, blue and purple berries, as well as red wine, are good sources of anthocyanidins. Flavanols are in tea, chocolate, berries, wine and apples. Citrus fruits and juices are excellent sources of flavanones, and soy products and legumes contain high amounts of isoflavones. Still other plant sources like parsley, celery, thyme, hot peppers, yellow onions, broccoli, kale and scallions contain flavonols and flavones.
Supplements vs. Food Sources
Much research remains on the role of flavonoids in human health. Therefore, doctors recommend that you obtain them from food sources whenever possible. Flavonoids come in the form of herbal supplements, but these products have no regulation by the Food and Drug Administration and are not proven safe or effective. For best results, incorporate fresh fruits and vegetables into your diet. Not only do they provide flavonoids, they are rich in other nutrients, like vitamins and minerals.