Green Tea

[dime]

Some interesting findings

http://www.rsc.org/chemistryworld/2012/ ... h-benefits
http://pubs.rsc.org/en/content/articlel ... c2fo30159h

[Maia]

It seems very interesting, but unfortunately I don't understand a lot of those words that they are writing there.
If you could explain to me what it is that they have actually found in those experiments that would be very nice of you

[dime]

Essentially they found that some tea polyphenols (like epigallocatechin gallate in green tea, theaflavin digallate in black tea) are actually binding to telomeres.
Telomeres are DNA pieces at the end of chromosomes, which are responsible for the chromosome stability and protect them from deteriorating or fusing with other chromosomes.
Deterioration/shortening of telomeres is implicated in many cancers, aging, etc. so the article may be explaining why tea drinkers statistically have lower rates of cancer - because these polyphenols are directly protecting the telomeres and thus preventing or slowing down the aging of cells.
The study is very limited though as it is in vitro, very isolated from an actual human, so the above is quite some speculation. But it's important as it will spark more research in this direction, so soon we'll know more details hopefully :)

[RRM]

The idea is that phenols from tea bind to DNA in our cells,
forming a protective coat, which is protective against radicals (such as HCA) that might damage DNA,
and potentially cause cancer.
And that if they bind to telomeres, that may protect us against aging.

Sounds good, no?
Now the other side of the story:

Tea drinkers just get a tiny little bit less cancer than other people,
which may be due to the lack of cancer causing HCAs, acrylamide etc in tea, replacing other drinks that do contain them.
Tea leaves are leaves, from bushes.
Any leave from any plant that you pick will be loaded with phenols.
(epigallocatechin gallate, for example, is related to tannins)
The good thing about tea leaves is that they are not toxic.
If you ever drank tea, you will know that the cup that you are drinking tea in,
will get coated with something that isnt that easily removed.
Thats because of the phenols in tea; they stick to pretty anything slightly reactive.
It doesnt matter whether that cup is steel, wood, glass, ceramic; the tea pehols will stick to it.
The same thing happens in your body,
as there is a lot of stuff that is more or less reactive in your body.
Would you like to have this superglue everywhere in your body?
Do you think that is a good idea?

[dime]

You can get HCA from other sources as well, besides cooked food, e.g. http://www.ncbi.nlm.nih.gov/pubmed/1749106
The idea of superglue in your body -- if it doesn't harm you in any way and offers you only benefits, why not?
Anyway, I'm not going to start drinking tea all of a sudden now :)

[RRM]

You can get HCA from other sources as well, besides cooked food

Yes, thats also on the WaiWiki page about HCA.

if it doesn't harm you in any way and offers you only benefits, why not?

Thats the whole point.
Two specific phenols showed selectivity for binding to quadruplex DNA over double-stranded DNA,
but that does not mean they dont bind to other stuff as well.
There are many, many reactive compounds inside the body, and most of them
have essential functions, so that binding by phenols is not a good idea.
Also, when phenols bind to reactive compounds, they may precipitate somewhere inside the body.
So, i can think of many good reasons how they can be harmful.
I think that this study is merely an investigation into the functioning of possible mechanisms of telomere protection,
without any practical implications.

[dime]

new potential benefit of a molecule in green tea: preventing the misfolding of specific proteins in the brain. The aggregation of these proteins, called metal-associated amyloids, is associated with Alzheimer's disease and other neurodegenerative conditions.
...
The specific molecule in green tea, ( -- )-epigallocatechin-3-gallate, also known as EGCG, prevented aggregate formation and broke down existing aggregate structures in the proteins that contained metals -- specifically copper, iron and zinc.

http://www.sciencedaily.com/releases/20 ... 145137.htm

[overkees]

Green tea is laden with fluoride.. I wouldn't even dare to consume small amounts of it.

[RRM]

Thats a generalization.
But yes, green tea may do so. Skeletal fluorosis from brewed tea
Black and green teas can contain significant amounts of fluoride.Whyte MP et al

[Novidez]

Today, I came across with this:

"Epidemiological observations and laboratory studies have shown that polyphenols present in green tea can reduce the risk of a variety of diseases including heart disease and cancer. The most abundant chemical components in the green tea drinks are catechins, which include epicatechin, epicatechin-3-gallate, epigallocatechin and epigallocatechin-3-gallate (EGCG). From these, the latter corresponds to more than 50% of total polyphenols, identified as the largest and most effective constituent of green tea . Thus, most laboratory and clinical studies of the effects of green tea based on EGCG .

The EGCG has been shown to help prevent the development of cancer cells and to destroy them, without affecting healthy cells.

Animal studies have shown that extracts of green tea and polyphenols present in this drink prevent the formation and development of tumors of different localizations. Furthermore, laboratory experiments with cancer cells from human lung and prostate cancer, have shown that the polyphenol derived from green tea have a clear anti - cancer activity.

In addition to preventing the growth of malignant cells and contribute to their destruction, polyphenols have a role in increasing the anticancer effects by decreasing resistance to chemotherapy and reduce side effects to the drugs used in this treatment. Also in the radiation polyphenols have been shown to increase the efficacy of treatment, as they contribute to decreasing its toxicity.

A recent approach to the polyphenols in cancer therapy may help increasing the effectiveness of conventional treatments, through adjustment of the dose and time periods for the desired results be achieved. In addition, it may facilitate the development of novel compounds of existing polyphenols in tea (and other) more effectively, either by increasing the availability for absorption by the body or because it can be specifically targeted to the organ to be treated."

New anticancer agents: recent developments in tumor therapy.
Combinations of plant polyphenols & anti-cancer molecules: a novel treatment strategy for cancer chemotherapy.
Epigenetic targets of bioactive dietary components for cancer prevention and therapy.
The chemopreventive and chemotherapeutic potentials of tea polyphenols.
[Molecular targets of tea polyphenols and its roles of anticancer drugs in experimental therapy].
[Tea polyphenols inhibits the proliferation of prostate cancer DU145 cells].

I would like to hear your opinions.

[RRM]

What does this tell us?
Tea contains compounds with medicinal properties.

This is true for most plants.
Compounds with medicinal properties are naturally present in most plants to deter various natural enemies.
Do you think it is a good idea for a healthy person to take medication in order to remain healthy?

[Novidez]

Do you think it is a good idea for a healthy person to take medication in order to remain healthy?

Ok. I got it
This answer of yours "This is true for most plants. Compounds with medicinal properties are naturally present in most plants to deter various natural enemies." suits also for that phenomenon called Hormesis, right?

[RRM]

suits also for that phenomenon called Hormesis, right?

The effects of exercise and fasting may (besides autophagy) also comprise hormesis.
Compounds with medicinal properties may affect various bodyfunctions without evoking hormesis.