Green tea is a health drink. This drink is contain many important stuf tou aour body. For antioksidan, keep uoung, and fresh your braing. Can green tea prevent or ease Alzheimer's disease, that devastating disease that can rob you of your ability to learn, reason, communicate, remember and carry out daily activities? Well, no one's saying that yet. But recent studies of the effects of green tea's catechins on animal brains are intriguing:
Delayed brain aging
A study of mice genetically programmed to age rapidly found that taking in green tea catechins on a daily basis prevented oxidative damage to the DNA in their brain cells, slowed memory loss and delayed brain aging.¹
Reversed mental deterioration
Another study of rapidly-aging mice measured the extent of their brain degeneration over time.² Mice that received green or oolong tea as their sole source of drinking fluid for 16 weeks reduced degenerative changes to their brains and actually reversed their mental deterioration. (These mice actually got smarter!)
Improved memory-related learning
Long term administration of green tea catechins to young rats lowered levels of damaging free radicals in a part of the brain that's vital to memory processing.³ The catechin-consuming rats also experienced improved memory-related learning ability, compared to those that didn't receive the catechins.
Less buildup of plaque
Finally, mice specially bred to develop Alzheimer's disease developed up to 54% less beta-amyloid buildup in their brains when they were given daily injections of the green tea catechin EGCg.4 Beta-amyloid plaques are believed to be a major cause of the brain cell death and dissue loss seen in Alzheimer's disease.
Of course, the big question still looms: Does green tea have the same effects in humans as it does in mice and rats? While few human studies of green tea's effects on brain function exist, one published in 2006 in the American Journal of Clinical Nutrition offers hope.5 Researchers gathered information from 1,003 Japanese men and women age 70+, measured their cognitive function, and tallied the frequency of their green tea consumption. After analyzing the data, the researchers concluded that, A higher consumption of green tea is associated with a lower prevalence of cognitive impairmenmt in humans." In other words, the more green tea they drank the less likely they were to have problems related to thinking and memory.
greentea.com
Sunday, February 1, 2009
A Cup Of Green Tea
You have to imagine it –a steaming, fragrant cup of green tea. The clear, pale green liquid gives off a delicious aroma somewhat like wet hay mixed with the scent of apples or pears. You lift the cup to your lips and take the first sip. The comforting liquid rolls over your tongue and eases down your throat, brightening and warming as it goes. Its slight astringency freshens your mouth, making it feel naturally clean. This warm, delightful beverage is soothing, especially if you take a moment to sit and sip it slowly. But at the same time, it’s also stimulating, giving you a much needed pick-me-up in the morning or the middle of the long afternoon. Is it any wonder that tea has been enjoyed for nearly 5,000 years – and that it’s the world’s most widely consumed beverage, next to water?
Yet green tea is a lot more than just a delicious and satisfying drink -- it also has medicinal properties that are nothing short of amazing. Way back in the year 1211 the Japanese monk Eisai wrote that "Tea is a miraculous medicine for the maintenance of health. Tea has an extraordinary power to prolong life." And today, scientific are confirming that what Eisai said may be true, finding that green tea can boost the immune system, inhibit the cancer process at virtually every stage, regulate cholesterol levels, assist in weight loss, fight free radical damage, and ward off viruses, fungi and food-borne bacteria. It also helps inhibit dental plaque formation, lower the risk of type 2 diabetes, slow cognitive decline, and may even help increase the lifespan. Virtually no other substance on earth can claim such a wide range of health benefits!
I’m Nadine Taylor, a Registered Dietitian with a great interest in the healing power of foods. I have been so impressed by the science behind green tea’s health benefits that I started collecting green tea studies and information about ten years ago and eventually wrote a book about it. My aim in this column is to bring that knowledge to you, explaining how green performs its health-promoting "miracles," telling about the fascinating history and customs of tea drinking, and revealing some interesting new tea tidbits. (Did you know that green tea extract can grow hair?) My articles and question-and-answer column will appear monthly, and I hope you’ll join me. And don’t forget to bring along a nice hot cup of green tea!
What is Green Tea, Anyway?
Green, black, oolong, herbal – what’s the difference? Well, first of all the word "tea" is correctly used only when it refers to leaves taken from the Camellia sinensis bush. And that means that herbal teas really aren’t tea – only green, black and oolong tea are the "real thing." That said, the way the Camellia sinensis leaves are processed will determine which of these three choices the end product becomes.
To make black tea, the freshly picked tea leaves must be fermented. Fermenting occurs when an enzyme in the tea leaf called polyphenol oxidase combines with oxygen, so the leaves are left in the sun to wither and dry for 18-24 hours, then broken up to encourage further fermentation.. Then firing the leaves stops the fermentation and dries them. Making oolong tea is similar, although the withering and fermenting processes are shorter, resulting in a partially-fermented leaf. But to make green tea the leaf isn’t fermented at all – in fact, just the opposite! The tea leaves are steamed almost immediately after picking in order to stop the fermentation process, after which they are rolled and dried.
The health benefits of the resulting tea will largely be determined by whether or not the tea leaf has been fermented. The fresh tea leaf contains large amounts of catechins (pronounced "CAT-i-kins"), powerful disease fighters and potent antioxidants that give green tea its health-enhancing abilities. But when exposed to air and polyphenol oxidase, the catechins change into completely different compounds called theaflavins and thearubigens. The theaflavins and thearubigens, which give black tea its distinctive taste, aroma and dark color, do have some health benefits, but not the same wide-ranging antioxidant and disease-fighting prowess seen in the catechins.
So in green tea manufacturing, it’s extremely important to rush the freshly picked leaves from the field to the manufacturing plant, being careful not to break or bruise them. There, the leaves are steamed or pan-fired immediately to inactivate the polyphenol oxidase. Afterwards, it’s safe to roll, twist, dry and package the leaves without worrying about obliterating the catechins. Yet even after the manufacturing process has been completed, green tea catechins can be destroyed if exposed to oxygen for too long. That’s why you should always keep your green tea in an air-tight container, even if it’s already in tea bag form. Remember: oxygen is the catechins’ worst enemy.
Yet green tea is a lot more than just a delicious and satisfying drink -- it also has medicinal properties that are nothing short of amazing. Way back in the year 1211 the Japanese monk Eisai wrote that "Tea is a miraculous medicine for the maintenance of health. Tea has an extraordinary power to prolong life." And today, scientific are confirming that what Eisai said may be true, finding that green tea can boost the immune system, inhibit the cancer process at virtually every stage, regulate cholesterol levels, assist in weight loss, fight free radical damage, and ward off viruses, fungi and food-borne bacteria. It also helps inhibit dental plaque formation, lower the risk of type 2 diabetes, slow cognitive decline, and may even help increase the lifespan. Virtually no other substance on earth can claim such a wide range of health benefits!
I’m Nadine Taylor, a Registered Dietitian with a great interest in the healing power of foods. I have been so impressed by the science behind green tea’s health benefits that I started collecting green tea studies and information about ten years ago and eventually wrote a book about it. My aim in this column is to bring that knowledge to you, explaining how green performs its health-promoting "miracles," telling about the fascinating history and customs of tea drinking, and revealing some interesting new tea tidbits. (Did you know that green tea extract can grow hair?) My articles and question-and-answer column will appear monthly, and I hope you’ll join me. And don’t forget to bring along a nice hot cup of green tea!
What is Green Tea, Anyway?
Green, black, oolong, herbal – what’s the difference? Well, first of all the word "tea" is correctly used only when it refers to leaves taken from the Camellia sinensis bush. And that means that herbal teas really aren’t tea – only green, black and oolong tea are the "real thing." That said, the way the Camellia sinensis leaves are processed will determine which of these three choices the end product becomes.
To make black tea, the freshly picked tea leaves must be fermented. Fermenting occurs when an enzyme in the tea leaf called polyphenol oxidase combines with oxygen, so the leaves are left in the sun to wither and dry for 18-24 hours, then broken up to encourage further fermentation.. Then firing the leaves stops the fermentation and dries them. Making oolong tea is similar, although the withering and fermenting processes are shorter, resulting in a partially-fermented leaf. But to make green tea the leaf isn’t fermented at all – in fact, just the opposite! The tea leaves are steamed almost immediately after picking in order to stop the fermentation process, after which they are rolled and dried.
The health benefits of the resulting tea will largely be determined by whether or not the tea leaf has been fermented. The fresh tea leaf contains large amounts of catechins (pronounced "CAT-i-kins"), powerful disease fighters and potent antioxidants that give green tea its health-enhancing abilities. But when exposed to air and polyphenol oxidase, the catechins change into completely different compounds called theaflavins and thearubigens. The theaflavins and thearubigens, which give black tea its distinctive taste, aroma and dark color, do have some health benefits, but not the same wide-ranging antioxidant and disease-fighting prowess seen in the catechins.
So in green tea manufacturing, it’s extremely important to rush the freshly picked leaves from the field to the manufacturing plant, being careful not to break or bruise them. There, the leaves are steamed or pan-fired immediately to inactivate the polyphenol oxidase. Afterwards, it’s safe to roll, twist, dry and package the leaves without worrying about obliterating the catechins. Yet even after the manufacturing process has been completed, green tea catechins can be destroyed if exposed to oxygen for too long. That’s why you should always keep your green tea in an air-tight container, even if it’s already in tea bag form. Remember: oxygen is the catechins’ worst enemy.
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