What are FLAVONOIDS?

Flavonoids, also known as bioflavonoids, are plant pigments, meaning they give the plants their color. They are present in most plants, concentrating in seeds, fruit skin, bark and flowers and more than 4,000 of them have been identified in plants.

Flavonoids in Tea
Common green and black tea leaves consist of about 25-30 percent flavonoids, including quercetin and gallic esters. Like the flavonoids in grapes and other fruits and vegetables, they also protect against heart disease.

For five years, Dutch researchers Michaël Hertog, M.Sc., and Edith Feskens, Ph.D., followed the dietary and lifestyle habits of 805 men ages 65-84 in the town of Zutphen. After accounting for the men's physical activity, smoking habits, and intake of vitamins C and E, and beta-carotene, the researchers found that men eating a lot of flavonoids-in tea, onions, and apples-were far less likely to suffer heart disease or heart attacks than men eating few flavonoids.

"There is evidence that free-radical oxidation of LDL plays an important part in atherogenesis," Hertog and Feskins wrote in Lancet (Oct. 23, 1993;342:1007-11). "Flavonoids are scavengers of free radicals...It is possible that quercetin and other flavonoids reduce the rate of formation of oxidised LDL and thus inhibit the growth of atherosclerotic plaques."

The benefits of tea flavonoids were confirmed earlier this year by researchers at the Saitama Cancer Research Center, Japan. K. Imai, PhD, and K. Nakachi, PhD, studied 1,371 men enrolled in a 40-year study of eating habits and health. They reported that elderly men who drank 10 or more cups of green tea daily had lower blood levels of cholesterol and triglycerides than men who drank less of the tea.

"Consumption of green tea was significantly associated with lower serum concentrations of lipids and lipoproteins," they wrote in the British Medical Journal (March 18, 1995;310:693-6). "An increase in consumption substantially decreased serum total cholesterol and triglyceride concentrations, and this strong association remained almost unaltered even after age, cigarette smoking, alcohol consumption, and relative body weight were controlled for."

The heavy tea drinkers also benefited from higher blood levels of the HDL and lower levels of the "bad" low-density lipoprotein (LDL) form of cholesterol. In addition, they had lower levels of certain liver enzymes, suggesting a reduced risk of liver disease.

"Green tea has many advantages over chemical preventive agents - tea is non-toxic and thus readily available to the general population," Imai and Nakachi wrote.

Drinking either green or black tea also protects against skin cancer by ultraviolet (UV) light and hazardous chemicals. In an experiment, Allan Conney, Ph.D., of the College of Pharmacy, Rutgers University, brewed four types of teas in concentrations comparable to what people drink: black tea, green tea, decaffeinated black tea, and decaffeinated green tea. He gave one type of each tea to four different groups of mice as their sole source of drinking fluid, then exposed them to either cancer-causing UV radiation or chemicals. For comparison's sake, he gave another group of mice plain water to drink. Conney reported in Cancer Research (July 1, 1994;54:3428-35) that the teas "markedly inhibited" the numbers and sizes of tumors.

Source:- The Color of Health
Why Nutrients Called Flavonoids Are Good For You
1994 by Jack Challem, The Nutrition Reporter

Flavonoids, like their better known chemical cousins, the carotenes, function as antioxidants and protect plants from damaging free radicals. The big difference is that flavonoids are water soluble, whereas carotenes are oil soluble.

The flavonoids were first isolated in the 1930s by Albert Szent-Gyorgyi, Ph.D., the Nobel laureate who discovered vitamin C. Szent-Gyorgyi found that flavonoids strengthened capillary walls in ways vitamin C could not and, at first, they were referred to as vitamin P. But the chemical diversity of flavonoids precludes their classification as a single vitamin.

The major dietary sources of flavonoids include fruit and fruit products, tea, and soy. Studies have found that the flavonoids in these foods protect against heart disease and cancer.

Flavonoids Tea

Ashitaba contains anti-oxidant flavonoids called chalcones almost unique to ashitaba and responsible for the yellow color of the juice. The chalcones that are in ashitaba are known as Xanthoangelol, Xanthoangelol-E and 4-Hydrooxyderricin and were discovered by Dr. Baba and studies, mostly performed in Japan, show its potent antioxidant activity protects against heart disease and cancer, enhances liver function and more (see chalcones) at a level exceeding that of red wine, green tea, or soy.

Antioxidant Flavonoids
(listed in order of decreasing potency)

Quercetin (a flavonol in vegetables, fruit skins, onions).

Xanthohumol (a prenylated chalcone previously found only in hops and beer)

Isoxanthohumol (a prenylated flavanone in hops and beer)

Genistein (an isoflavone in soy) Pro-oxidant flavonoids

Chalconaringenin (a non-prenylated chalcone in citrus fruits)

Naringenin (a non-prenylated flavanone in citrus fruits)

Source:-Antioxidant Activities of Flavonoids
Dr. Donald R. Buhler and Dr. Cristobal Miranda

See also chalcone - ashitaba's antioxidant.

See how AshitabaGreen has helped others by reading our testimonials

Back to FAQ's