Archive for the ‘Tea’ Category
The second most consumed beverage behind water is tea. Interestingly enough the 3,200,000 tones of tea produced worldwide come from only one plant species, named “camellia sinensis.” But how a plant becomes a beverage? Tea is made by steeping processed leaves, buds, or twigs of the tea bush in hot water for a few minutes, a great variety of tea tastes, aromas and colors can excite even the more skeptical drinker. If you do like tea drinking, but simply never had the opportunity to learn more about it beyond the fact that you enjoy it, you should know that there are thousands of kinds of tea offered on today’s market. Shades in flavor derive from the region of cultivation and the method of processing the tea leaves. It is the processing techniques that produce the four simple tea categories are considered the art of tea making. In its most basic form, processing is the taking of the raw green leaves and deciding whether or not, and how much oxidation (or fermentation) should take place before drying them out. Oxidation is the reaction of the enzymes contained in tea leaves when they are broken, bruised or crushed.
The first category is that of black tea. Black tea is nothing more than the leaves of the camellia sinensis after being exposed to 8-24 hours of open air. After the leaves are picked up they are spread out to let the water they contain evaporate. You have probably witnessed it happening to a flower that is left without being watered. The foliage curls up and begins to dry. After this part of the process, the tea leaves are balled into rolls that encourage oxidization. When fully oxidized, the leaves turn into a rich black color. Tea producers then put the tea leaves into the final drying period before sorting and packaging them.
Oolong tea is another tea category and is considered to be the most difficult of the four types of teas to process. The best way to describe oolong tea is that it is somewhere in between green and black tea. This is because the leaves are only partially oxidized during the processing. As with black tea, the leaves are spread out to dry for 8-24 hours, but after that, they are tossed about in a basket in order to create a bruising and partial exposure to the air. The final step involves steaming the leaves, which neutralizes the enzymes in the tea and prevents further oxidization.
Green teas, like white teas, are closer to tasting like fresh leaves of grass that the other two tea categories. This type of tea is also lower in caffeine and has higher antioxidant properties. The whole process of creating green tea revolves around preventing oxidization from taking place in the leaves. Though the tea leaves are sometimes laid out to dry for a few hours, then, in order to neutralize the enzymes and prevent further oxidation, the leaves are steamed or pan fried. It is this very technique which results in the preservation of the enzymes which have recently become the focus of medical research. After steaming, the leaves are rolled up, still quite green in color.
Finally, white tea has recently become a popular item in the west as it is the least processed tea and thus tastes the most like fresh leaves or grass. White tea is made of the little buds of the tea plant. Again like green tea, white tea is steamed or pan fried to prevent any kind of oxidization, and great care is taken to avoid bruising or crushing the tea. The dried buds have a silver-like appearance because the tiny white hairs of new growth are still present.
There are dozens of variations of food poison, and none of them are pleasant. One of them is Bacillus cereus. While not usually life threatening, this common form of food poisoning can cause diarrhea, nausea, cramps and vomiting. Symptoms usually appear 8-16 hours after exposure to the bacteria, and can disrupt your life for a few days.
Bacillus cereus is usually caused by improper cooking. The problem can be exacerbated by improper refrigeration, which just allows the spores to further grow. Cooked rice that is improperly refrigerated is one of the most common carriers of bacillus cereus.
However, researchers are learning that there may be ways to protect our bodies from the ravages of such bacteria. It appears that tea’s catechins may protect our bodies from bacteria like bacillus cereus. Tea has far more anti-microbial properties than previously realized.
One particular study reported by the UK Tea Council evaluated the anti-microbial activity of seven green tea catechins and four black tea theaflavins, both important anti-oxidants. They also evaluated actual infusions of 36 commercial black, white, green and oolong teas, as well as herbal teas.
These anti-oxidants and infusions were evaluated to determine their anti-microbial activity against bacillus cereus. This study concluded that all eleven of the anti-oxidants evaluated contained anti-microbial properties.*
In fact, most of the compounds were more active than medicinal antibiotics such as tetracycline or vancomycin at comparable concentrations. The study also concluded that the brewed infusions of true tea that contained these catechins and theaflavins also had anti-microbial properties as well, particularly freshly brewed infusions. However, herbal brews did not have anti-microbial properties.
So, just what does this mean to our real life? Well, it means that drinking tea can protect your body against certain harmful bacteria like bacillus cereus. If we consume tea on a regular basis, we may be able to ward off these harmful bacteria before they wreak havoc on our bodies.
The presence of the anti-oxidants in tea may be enough to keep us from getting sick from these bacteria, or at least be sufficient to lessen their effects.
This is likely just the tip of the iceberg. We already know that green tea prevents many serious illnesses, such as heart disease, Alzheimer’s disease and some forms of cancer.
And, if we’ve determined that it can kill bacteria such as bacillus cereus, then there’s certainly potential that it can act as an anti-biotic against other harmful bacteria, as well.
Certainly it has been determined from this along with many other studies that tea is an important part of living a healthy life. In Japan, the medical community recognizes green tea as a known cancer preventative, and it’s likely that medical communities in other countries will soon follow suit.
This information, combined with the other studies that have shown green tea to be effective in preventing heart disease should be enough to convince us that drinking a few cups of green tea each day is a simple way to protect our health.
But, why is does it seem that so many of the positive findings are associated with green tea, and not black tea too? Well, it stems from the way the tea is processed. While the study noted here on the anti-microbial activity of tea didn’t find a difference between the two, in most health studies green tea beats black tea every time.
Black tea is fermented during processing; green and white teas are not. The fermentation process changes the anti-oxidants in the tea from their natural, original state, into a slightly different compound.
While black tea is still healthy, and still contains important anti-oxidants, the more natural anti-oxidants in green and white tea are far more powerful.
The research done so far has mostly been performed on green tea because it is much more widely consumed. However, it is likely that researchers would find that white tea is just as healthful, since its anti-oxidants are preserved in their natural state, just like those in green tea.
Green tea first gained notice as a health preserver because of the much lower incidence of heart disease and cancer in Asian countries, where green tea is a staple. Scientists decided to back up this anecdotal evidence with research and the findings have been astonishing.
In addition to evidence suggesting that green tea protects our health, there has also been evidence to suggest that green tea may even be effective as an alternative cancer treatment. Some studies have shown that green tea slows the growth of certain cancers.
Other studies have shown that administering green tea along with chemotherapy makes the chemotherapy more effective than when it is administered alone.
So, it appears that green tea may be one of the most promising natural health products we can consume. As time goes on, and more studies are conducted on human subjects, we’ll learn more definitive information about this wonder beverage.
It’s amazing to think that something many of us have been drinking all our lives just for the taste could hold so much power to protect our health.
Some of the most promising cancer research going on today involves the use of green tea and its ability to prevent cancer and even treat cancer in patients who have already been diagnosed with the disease. Researchers are examining many possibilities for how green tea might be used, and working to determine the cancer types for which it holds the most promise.
Over the last few years, scientists have learned a great deal about the importance of a diet rich in anti-oxidants. Anti-oxidants are a powerful tool in slowing down the aging process and preventing disease. They are even more important than even with the number of processed foods we consume. Fresh fruits and vegetables are rich in anti-oxidants, as is dark chocolate and green tea. Coffee is also a source of anti-oxidants, though it is not nearly as rich in them as green tea.
The process our bodies go through to convert our food to energy creates free radicals each day. Free radicals are oxygen containing molecules that damage our cells and DNA. If we don’t combat them, the make us age more quickly, they contribute to the development of blocked arteries and the make us more susceptible to the diseases and problems of aging.
So, it’s certain that we all need to consume a high level of anti-oxidants as part of our everyday diet. But, of particular interest are the anti-oxidants in green tea. Asian cultures consume a large amount of green tea, and have espoused its healing properties for centuries. And, it just so happens that they have a much lower incidence of cancer and heart disease.
There are, of course, other differences between Asian culture and ours. Notably, we are far more likely to be overweight; and research has shown us that obesity is a significant risk factor for many diseases including cancer and heart disease. However, one other interesting fact; Asian cultures, particularly Japanese men are far more likely to smoke than we are, yet they still have a much lower incidence of cancer and heart disease.
So, green tea is of significant importance in our quest to live longer and be healthier. There are hundreds of studies that have shown that green tea is a good cancer preventative and can increase the effectiveness of cancer treatments.
One important study is linked to skin cancer. According to the American Cancer Society, skin cancer is the most common of all cancers. Melanoma is the most deadly form of skin cancer. While only 4% of skin cancer cases are melanoma, it causes more deaths than any other type of skin cancer.
The number of new cases of melanoma is on the rise in the US- an estimated 62,000 Americans will be diagnosed in 2006, and about 8000 people will die from melanoma in the US this year. Nonmelanoma is extremely common. It is estimated that about one million people develop nonmelanoma cancer each year; this is about the same number of people who contract all other types of cancer combined. However, people rarely die from nonmelanoma – only about 1000 each year in the US.
Since skin cancer is so prevalent in our country, it’s critical that we spend time and money researching how we can treat this cancer. Of course, skin cancer is, in part, preventable. So, as part of a healthy lifestyle we should be diligent about protecting ourselves from the sun, because this is the most important aspect of preventing both types of skin cancer.
To reduce your risk of skin cancer, be sure that you are always protected from the sun, even on cloudy days, and even in the winter. Cover as much of your body as possible with clothing, and use sunscreen with an SPF of 15 or higher on any areas that you cannot cover. Be sure to follow the directions on sunscreen closely; many people do not use enough sunscreen and do not reapply it often enough.
As scientists are researching ways to prevent and treat skin cancer, the results involving green tea are promising. One particular study reported by the Alternative Medicine Review showed excellent results in skin cancer prevention and treatment in mice with the use of green tea both applied topically and given orally*.
In this study, mice were exposed to about seven different kinds of carcinogens, all of which are known to cause or contribute to skin cancer. The mice were divided into groups. Some of the groups were treated with green tea by substituting it for their drinking water. Others were treated topically with green tea extract. Some of the groups of mice were already suffering from skin cancer, as well.
The research was conducted so that mice undergoing exposure to each different carcinogen were treated with green tea in both forms. For example, some of the mice being exposed to UVB rays were treated with only oral green tea, while others were treated with only topical green tea extract.
The research concluded that all of the mice benefited from the green tea treatment, whether it was given orally or applied topically. In every group, the green tea was effective at preventing skin cancer. The study found that green tea applied topically seems to scavenge and destroy skin cells that are likely to become cancerous before they can mutate.
The green tea, whether given orally or applied topically, slowed down the cancer growth in the mice that were already infected. In addition, green tea given orally seemed to cause some regression of existing skin cancer.
Of course, these results are very promising. If this research is a good indicator of how green tea might work in humans, as well, then topically applied green tea may become the new trend in skin products. In addition, these findings support other findings that conclude that drinking green tea is effective in preventing and treating many forms of cancer.
The next step, of course, is to conduct human trials to see if the same results prove true. It certainly seems that we have enough information to suggest that green tea should be part of everyone’s diet for its ability to slow down aging and prevent disease.
The most exciting news from this study is the idea that we might benefit dramatically from the simple step of applying a form of green tea to our skin. Addition of green tea to our sunscreens, lotions and moisturizers could have a dramatic effect on the number of skin cancer diagnosed each year. And, even for those already diagnosed with skin cancer, green tea applied to the skin might prove to be an effective treatment to kill the cancer cells, or at least slow down their progression.