Lead extraction with green tea: AAS reveals efficacious lead

[auhckw]

Lead extraction with green tea: AAS reveals efficacious lead detox
http://www.spectroscopynow.com/coi/cda/ ... d=1&page=1

[October 15, 2010]

Brewing up lead treatment

Atomic absorption spectroscopy and other techniques have been used to study the effects of green tea extract on reducing lead toxicity in laboratory rats. Green tea is tea brewed with the unprocessed leaves of Camellia sinensis. Green tea originates from China and has become associated with many cultures in Asia from Japan and South Korea to the Middle East. Black tea by contrast is more familiar in the West and is made from the "oxidised" leaves, which gives it a stronger flavour.

There have been various medical claims made for all forms of tea, but green tea extract has come to the fore as having unproven health benefits, such as helping with weight control, lowering the risk of cardiovascular disease and cancer. The presence of antioxidants including polyphenols and the presence of the stimulant caffeine are all considered in the general assessment of tea's physiological effects. Green tea extracts are herbal derivatives from green tea leaves that contain antioxidants, mainly green tea catechin polyphenols (GTC).

Green tea extract has been linked to lower cholesterol levels in animal studies and in humans GTE apparently increases the rate of fat oxidation in the body while modulating insulin activity. Obtaining proof of such benefits is fraught with epidemiological hazards. However, atomic absorption spectroscopy can demonstrate quantitative changes in levels of metal contaminants in a sample that would indicate benefits in some contexts. For instance, if GTE were able to chelate toxic lead ions in the body and allow them to be flushed out by the kidneys then that health effect could be demonstrated in a relatively straightforward way.

Lead toxicity

Green tea is tea made solely with the leaves of Camellia sinensis that have undergone minimal oxidation during processing. Green tea originates from China and has become associated with many cultures in Asia from Japan and South Korea to the Middle East.

Now, writing in the journal Atomic Experimental and Toxicologic Pathology, an international team based in Egypt and India, report on a study into lead toxicity amelerioration with GTE in male Sprague-Dawley rats. Lead is a common cause of chronic health problems in humans and poisoning of domestic animals throughout the world. The early stages of inorganic lead exposure are manifested by loss of appetite, weight loss, constipation, irritability, fatigue, occasional vomiting, lead line of gums and anaemia. Health risks associated with lead exposure from industrial and environmental sources are now well recognized and it is known that the metal interferes with many biochemical and physiological functions.

E.E. Mehana of the Department of Pathology, College of Veterinary Medicine, Alexandria University, M.A. Meki of the Department of Biochemistry, College of Medicine, Assiut University, in Egypt, and Khalid Majid Fazili of the Department of Biotechnology, University of Kashmir, Srinagar, J&K, in India, studied four groups of rats. They gave the animals lead and GTE orally with drinking water for 8 weeks. "Lead concentration in the digested tissues of liver was detected using atomic absorption spectroscopy," the team explains, and "the activities of glutathione-S-transferase (GST) and superoxide dismutase (SOD) were used as markers to evaluate the antioxidant status of tissues."

They found that exposure to lead alone reduced the antioxidant capacity of the liver. However, this was reversed to some degree by ingestion of green tea extract. The team explains that the levels of liver enzymes ALT, AST and ALP and serum protein determinations showed that GTE has a protective effect on liver function in the face of lead. "Histopathological studies of liver revealed that supplementation of green tea extract resulted in mild degeneration and congestion of the blood vessels and an enhanced regenerative capacity," the team adds."

[JBaymore]

WOW. Thanks for posting this. Will research it more. VERY Interesting if it stands up to broader peer-reviewed scrutiny.

best,

................john

[britt]

Green tea extracts are just that; they extract certain elements of the tea while leaving out others. The natural balance of tea is not preserved in an extract.

Green tea extracts vary in ingredients from one brand to another. Some appear to be very pure while others seem to be loaded up with other ingredients.

The green tea extracts I've seen limit the usage to several times per day and classify the extract as an over-the-counter drug or medicine.

Personally, I'll stick with brewing the real thing and avoiding the extracts.

I wonder what the results would be in this test if whole green tea was used on the subjects instead of the extract?

[beforewisdom]

Scientists use green tea extracts as the extracts can be standardized. They know what they are using. What is one cup of tea can vary very much from another. It is also hard to get a rat to drink tea.

The scientists miss the point though. People want to know if drinking tea helps people.

Rats are not people. Extracts are not green tea.

Extracts maybe more potent, but there may be more things in tea that are efficacious that extracts to not have. It may also be the case that a number of things have a synergistic effect in tea.

[chingwa]

[AdamMY]

The scientists miss the point though. People want to know if drinking tea helps people.

Rats are not people.

I am not saying this is not true, but when scientists run tests like this on animals they often choose animals that have been shown to have similar bodily reactions to substances as people do. That being said it is often easier to see potential effects in lab animals as the scientists can make sure every animal has an identical diet, and is kept in rather identical conditions. Basically they are trying to remove as much of a cause for statistical noise as they can.

I mean I suppose you could do similar tests on people but you would need to convince them to basically be in a jail like scenario during the duration of this experiment.

[beforewisdom]

All true, but it doesn't take doesn't take away from the fact that tests of extracts on rats doesn't amount to more than a good guess that actual tea might do something for human beings.

You are the right, the scientists, out of practical reasons have to use less than a perfect situation.

However, any honest researcher will tell you that Stage 1 human trials of drugs that have been tested on animals are extremely dangerous trials for people. That is because 90% of the drugs tested on animals don't have the same effects on human beings as on animals.

[edkrueger]

Where did you get that statistic from?

[beforewisdom]

http://www.huffingtonpost.com/simon-cha ... 71845.html

[edkrueger]

I see, in an editorial in a not very reputable newspaper written by a layman/blogger/animal rights activist without a citation.

[beforewisdom]

I see, in an editorial in a not very reputable newspaper written by a layman/blogger/animal rights activist without a citation.

Hi Ed;

You can google on "stage 1 trials", you will find similar statements in other places.

I still stand by my opinion that feeding extracts to animals doesn't prove that people drinking green tea can expect tangible health benefits.

I just finished a book on green tea by a green tea connoisseur who died of cancer at the age of 74. Maybe the green tea gave her a few more years, maybe not.

[Cyphre]

I see, in an editorial in a not very reputable newspaper written by a layman/blogger/animal rights activist without a citation.

Don't attack the source. Show stats, or facts from other sources to challenge the information. Whether someone trusts the news source doesn't mean that what they are saying is automaticlly wrong. Claiming that you know about the author based on where they work is personal bias, too.

[AdamMY]

I see, in an editorial in a not very reputable newspaper written by a layman/blogger/animal rights activist without a citation.

Don't attack the source. Show stats, or facts from other sources to challenge the information. Whether someone trusts the news source doesn't mean that what they are saying is automaticlly wrong. Claiming that you know about the author based on where they work is personal bias, too.

I believe the main things he was drawing attention to were the lack of citation and the fact that it was an editorial. Editorials for the most part are opinion pieces, and more likely to avoid the fact checking which is supposed to go on in Newspapers.

[beecrofter]

Quite allright but the local rats are healthy enough.

[Chip]

I have just one thing to say ... tell those rats to get the lead out!