The chemical compound known as a phenol is characterized by an aromatic benzene ring with a hydroxyl group (OH) attached. This makes sense that poly-phenols refer to a chemical substance with more than one phenol group. Phenols function as potent antioxidants, reacting with free radicals. Phenols are responsible for the bright coloring in many fruits and vegetables. These fruit and vegetable phenols protect the plants from damage by disease and ultraviolet light.
Polyphenols are phytonutrients or phytochemicals. Phytonutrients are biologically active compounds in food. However, these phytonutrients are not classified as essential nutrients. This is because the body does not depend on these nutrients for proper bodily function. Phytonutrients do play a vital role in affecting our health just as significantly as vitamins and minerals do.
Polyphenols are classified as flavonoids, which is a class of phytonutrient. Polyphenols can form complexes with metal cations such as iron, zinc, and copper. This reduces the absorption of the mineral. This is beneficial because excess levels of these cations promotes the generation of free radicals. Polyphenols are potent free radical scavengers in the body. Polyphenols also protect and regenerate other dietary oxidants such as vitamin E.
Polyphenols are plentiful in green tea. Polyphenols have been found to be more powerful as an antioxidant than even vitamins C and E. In particular, EGCG or epigallocatechin gallate is the major polyphenolic constituent of green tea. EGCG is a potent antioxidant. A number of chronic diseases have been thought to be caused by free radical damage such as cancer, aging, and heart disease.
Antioxidants protect the body from free radical damage. What are free radicals? Free radicals are caused by cigarette smoking, radiation, pollution, and herbicides. Free radicals are atoms with unpaired electrons in the outer shell. The unpaired electrons make free radicals unstable. Free radicals want only to be stable. Free radical stability requires the electrons to be paired. Free radicals are extremely reactive and will oxidize the nearest molecule.
Oxidizing causes the free radical to gain an electron but also creates another free radical. This creates a chain reaction continuing until the disruption of a living cell. Free radicals can attack proteins, carbohydrates, lipids, and DNA. However, DNA is usually preferred. DNA and free radical interactions usually result in mutations that adversely affect the cell cycle and potentially lead to malignancy. In fact, researchers believe this is how many forms of cancer arise.
Antioxidants protect the body from damaging oxidation reactions. Antioxidants safely interact with free radicals to prevent damage to vital molecules. Antioxidants donate an electron to the free radical, hence stabilizing the free radical and preventing damage. The antioxidant is stable with or without the electron, making this a win-win situation.
Polyphenols can be found in white, black, and green tea. Of course, the level of polyphenols along with other nutrients is based on how the tea is processed. Steamed white and green tea retains more polyphenols and nutrients than roasting and fermenting. Black teas and some green teas are fermented and roasted, damaging the bioactive substances in the tea leaf.
Why should you drink green tea? Many studies have been done on the health benefits of green tea. Dietary intake of green tea has been linked to a reduced risk of cancer and heart disease. Regular consumption of green tea shows no significant side effects. Green tea helps prevent cavities, strengthens teeth, and is thought to kill oral bacteria that is responsible for bad breath. Green tea has been shown to protect the brain from oxidative stress and lower monoamine oxidase activity; preventing age related brain degeneration. Green tea studies suggest an increase in exercise endurance by improving the metabolism of fat.
Green tea offers many health benefits to those who drink green tea regularly. Besides offering antioxidant benefits, green tea is excellent as a weight loss supplement offering weight loss results and safety. Of course, green tea should be used in combination with a healthy diet and exercise program. If you take medications for a health condition, consult your doctor before adding green tea to your diet.
Copyright 2006 Kristy Haugen
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