Green Tea Research

Wai Jia: The Kung Fu Forum Kung Fu Training and Health
21

Green tea polishes hard drive heads

18:10 27 April 04

NewScientist.com news service

Green tea provides a more effective and environmentally-friendly method of preparing computer hard disks, say US scientists.

Inside a hard drive a component known as a read-write head is used to magnetically impart and retrieve information from a spinning disk. The point of this head must be extremely smooth as it travels on a microscopically thin layer of air above the disk’s fast-moving surface.

In fact, imperfections larger than 10 angstroms (a billionth of a metre) may interfere with the normal operation of the head.

So manufacturing a new read-write head involves smoothing it using a diamond instrument before using abrasive chemicals to remove any particles that still cling to the newly polishing surface.

But John Lombardi, at Ventana Research based in Tuscon, Arizona in the US, suspected that green tea might also provide be an effective compound for polishing magnetic read-write heads. This was because tannin, a chemical that gives tea and coffee a bitter taste, binds to certain ceramic and metal materials. It is this quality that causes it to stain teapots and mugs.

Plant extracts

Together with researchers at Pace Technologies in Arizona, and the University of Arizona, Lombardi developed a polishing mixture using tannins and other plant extracts from green tea. The precise formula remains a secret but Lombardi says it is not only more effective than existing compounds, but also less environmentally harmful because it is biodegradable.

The researchers combined chemicals from green tea with synthetic proteins and an abrasive chemical it produced a mixture well suited to removing microscopic imperfections. By binding to these particles, the mixture gives them an electrostatic charge, causing them to be repelled from the platter’s surface.

“The tannin phytochemicals play a dual role by increasing the polishing rate and enhancing the removal of particles produced by the polishing process,” says Srini Raghavan at the University of Arizona.

Further testing of the fluid is required before it can be used commercially. But Lombardi hopes this will be completed by the end of 2004.

Will Knight

Return to news story

© Copyright Reed Business Information Ltd.

22

White Tea Kills More Germs Than Its Green Cousin

19 minutes ago Add Health - HealthDay to My Yahoo!

TUESDAY, May 25 (HealthDayNews) – White tea seems to be more effective than green tea in fighting germs, says new Pace University research.

“Past studies have shown that green tea stimulates the immune system to fight disease,” study author Milton Schiffenbauer, a microbiologist and professor in Pace’s department of biology, said in a prepared statement. “Our research shows that White Tea Extract can actually destroy in vitro the organisms that cause disease.”

“Study after study with tea extract proves that is had many healing properties. This is not an ‘old wives’ tale,’ it’s a fact,” Schiffenbauer added.

The study was presented May 25 at the American Society for Microbiology general meeting in New Orleans.

The researchers found that:

The anti-bacterial and anti-viral effect of white tea is greater than that of green tea.

The addition of white tea extract to several brands of toothpaste enhanced their anti-viral and anti-bacterial properties.
White tea extract had an anti-fungal effect on both Penicillium chrysogenum and Saccharomyces cerevisiae.
White tea extract may help inactivate bacteria, viruses and fungi that affect humans.

More information

The U.S. National Cancer Institute (news - web sites) has information about tea and cancer prevention.

23

Okay, its a Black Tea Study but, “what the Heck!”

Black Tea May Help Get Blood Circulating

1 hour, 49 minutes ago Add Health - Reuters to My Yahoo!

By Amy Norton

NEW YORK (Reuters Health) - A cup of black tea may give a quick boost to blood flow to the heart, the results of a small study suggest.

In an experiment with 10 healthy men, Japanese researchers found that blood-flow in the coronary arteries improved two hours after the men drank black tea. The same was not true of a caffeinated drink used for comparison.

Numerous studies have suggested that tea drinking may do a heart good, with effects on cholesterol, blood clotting and blood vessel function being among the proposed mechanisms.

The new study, reported in the American Journal of Cardiology, suggests it also has a more immediate beneficial effect. The authors suspect that black tea improved the dilation of the men’s blood vessel, allowing better blood flow.

Tea is rich in antioxidant compounds called flavonoids, and these may be the key to the beverage’s potential heart benefits, study co-author Dr. Kenei Shimada of Osaka City University told Reuters Health.

For the study, the researchers used a special ultrasound method to gauge “coronary flow velocity reserve” or CFVR. This reflects how much blood-flow can speed up when demands are put on the heart, and paints a picture of the healthiness of the coronary circulation.

Shimada’s team measured the CFVR of each of the men after they drank either black tea or a caffeinated beverage, and found that it increased significantly after the black tea.

“The results of this study suggest that black tea consumption has a beneficial effect on coronary circulation,” the researchers report.

They speculate that the flavonoids in black tea improve the functioning of the lining of the blood vessels, increasing how much the vessels dilate in response to blood flow. Dysfunction in this lining, called the endothelium, is one of the things that goes wrong as heart disease develops.

It’s not clear what the long-term implications of the findings on CFVR might be, but Shimada said research has shown coronary flow reserve to be related to heart disease risk.

Larger studies, particularly in people with coronary artery disease, are needed to establish how tea affects the coronary circulation, the researchers conclude.

SOURCE: American Journal of Cardiology, June 1, 2004.

24

Here’s some stuff I stumbled upon:

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15236762

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15226633

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15083319

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=14759162

25

^ Cliff’s Notes?

How much caffiene to black and green tea have compared to coffee? And wouldn’t their relative strengths depend on thing such as how long they were steeped, etc.?

26
  1. Antioxidative effect of green tea believed to have a preventive effect on brain atrophy in aged mice, assesed by learning time in a maze for mice in different stages of atrophy.
  2. Study group of 203 in Japan showed that consumption of green tea was associated with lower incidence of coronary artery disease
  3. Rats on a high fructose diet exhibited hypertension and insulin resistance and showed improvement in both after green tea supplementation
  4. Green tea increased insulin sensitivity in rats
27

when you talk of “green tea” is this green tea in general or a specific kind of green tea?

28

RAF

Tenren tea is the best. There’s a really good tea store in Toronto’s chinatown that carries it. Their ginger tea is the best I’ve had.

29

red5, green tea in general. I like Temple of Heaven gunpowder.

30

Spark, I agree. TenRen Tea is excellent. I often buy the White mo li hua cha.

I need to visit Toronto. Heard great things about the China town.

31

Drinking Tea Keeps Blood Pressure Down – Study

Mon Jul 26, 4:07 PM ET

CHICAGO (Reuters) - Drinkers of green and oolong tea are less likely to develop high blood pressure than nondrinkers, a Taiwanese study said on Monday.

The risk of hypertension, a condition that can lead to heart disease and stroke, declined the more green or oolong tea was consumed regularly, the study by researchers from National Cheng Kung University in Tainan, Taiwan, said.

Some varieties of tea contain 4,000 chemical compounds, including flavonoids that help protect against heart attacks, strokes and kidney failure, study author Yi-Ching Yang wrote in the report published in The Archives of Internal Medicine (news - web sites).

None of the 1,500 participants suffered from hypertension at the start of the study, and those who drank between 120 and 599 milliliters (4 to 20 fluid ounces) of tea per day for at least a year prior had a 46 percent lower risk of developing high blood pressure than nondrinkers.

Drinking 600 milliliters of tea or more a day lowered the risk of hypertension by 65 percent, the study showed.

Few of the participants drank black tea.

About 40 percent of the study subjects were regular tea drinkers, and they were more likely to be younger men who smoked more, drank more alcohol and ate fewer vegetables.

32

Some brewing instructions reccomend a second and/or third steep. Anyone know how this effects level of active ingredients? Obviously it would be less but…90%… 10% ??

Ten Ren medium grade Lung Ching:D

33

Sorry, nothing to add, aside from congratulations on creating such a fantastic thread on the many merits of tea. For this, you have the keys to England and are welcome anytime.

Just so happens I bought my first batch of green tea before stumbling upon this thread too. Hooha!

34

don’tcha just love being proven right? :smiley:

35

Originally posted by Yang Fool
[B]Some brewing instructions reccomend a second and/or third steep. Anyone know how this effects level of active ingredients? Obviously it would be less but…90%… 10% ??

Ten Ren medium grade Lung Ching:D [/B]
You mean using the same tea for multiple cups? I use a coupla teaspoons of tea per litre in my thermos each day. It’s about right. Afterwards I make a cup for my wife with the same tea. It ends up really weak and you have to leave the tea in for a long time and keep agitating it to extract any greeny goodness. Same thing to a lesser extent if we make two cups in a row from one lot of tea. The 2nd is always noticeably weaker. It’d be better to use fresh tea each time. I usually leave the 1st lot brewing for 3min and the 2nd as long as necessary. Always use fresh water in the pot (don’t keep reboiling) and I also like to stop it just before boiling since IIRC it’s supposed to brew best at about 80 degrees celcius.

36

Yeah exactly- same tea, multiple cups. I do pretty much as you said, first steep 3 minutes, water just below boiling. Second steep I leave between 5 and 10 minutes depending on what I’m doing in morning. It’s noticibly weaker tasting even if it sits long enough to get good and green. I wonder how much less medicinal content it has?

I read a translation of an old tea brewing song-instruction that had really cool stuff like- “don’t be rude to the leaves by pushing them harshly” and “let the water whisper and gossip but not talk”.
I can tell when the water is just under boiling temp as it starts making “that sound”.

I raise my cup to you-

37

Originally posted by Yang Fool
Second steep I leave between 5 and 10 minutes depending on what I’m doing in morning. It’s noticibly weaker tasting even if it sits long enough to get good and green. I wonder how much less medicinal content it has?
I guess I’m just too cheap to make a fresh brew for each cup :(. I shouldn’t be considering my tea is pretty cheap (AUD$4.50/250g). But yeah, the 2nd is definitely sub-par.

Originally posted by Yang Fool
I raise my cup to you-
raises back :smiley:

38

Of course tea can help people lose weight.

Originally posted by RAF
[B]

•and possibly helps people lose weight.

[/B]

Yeah, it’s 0 calories, 0 fat and fills your stomach up if you drink three cups of it. I’ve known that for a while. Part of my personal diet plan is every time I think of getting a cola I just brew a pot of good 'ol “Seven-Leaf Tea” (brand of Green Tea I found in one of the local Asian groceries, best tea I have ever had) instead.

39

Originally posted by RAF

I need to visit Toronto. Heard great things about the China town.

Toronto does have a nice Chinatown. One time, I was in Toronto at a conference and the bunch of us went to this Vietnamese restaurant just on the edge of Chinatown. This was a restaurant that was not used to catering to non-Vietnamese, the menu was not written in English. There was (in fact) no english menu. I eventually ordered something labled as “noodles and ‘meat’ wrapped in tropical leaves” according to the waiter who assured me it was very tasty. It was. I also ordered a small dumpling soup that came in a bowl that could be described with many words, small not being one of them. My comment was “I’d hate to see the large” One advice though, don’t order a drink called “pickled plum” just trust me, stick to the tea! :smiley:

40

Green Tea and Cancer

Green Tea Seems to Stem Spread of Prostate Cancer

23 minutes ago

WEDNESDAY, Dec. 1 (HealthDayNews) – Green tea appears to inhibit the spread of prostate cancer in a number of ways, says a study in the Dec. 1 issue of Cancer Research.

In research with mice, scientists from the University of Wisconsin and Case Western Reserve University in Cleveland found green tea polyphenols (GTP) target molecular pathways that control the proliferation and spread of prostate tumor cells. The polyphenols also inhibit the growth of blood vessels that feed prostate tumors.

“Consumption of GTP led to reduced levels of IGF-1 (insulin-like growth factor-1),” study senior author Hasan Mukhtar, of the department of dermatology at the University of Wisconsin, said in a prepared statement.

“GTP also led to increased levels of one of the binding proteins for IGF-1, the insulin growth factor binding protein-3. These observations bear significance in light of studies that indicate increased levels of IGF-1 are associated with increased risk of several cancers, such as prostate, breast, lung and colon,” Mukhtar said.