JRMoney15 said:Is the fluoride from the water or the tea
Fluoride was given separately to compare effects of known thyroid inhibitors rather than mimic fluoride levels found in tea naturally.
Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Click Here if you want to upgrade your account
If you were able to post but cannot do so now, send an email to admin at raypeatforum dot com and include your username and we will fix that right up for you.
JRMoney15 said:Is the fluoride from the water or the tea
BobbyDukes said:jyb said:BobbyDukes said:The only way tap water gets into my body is through showering, and through my coffee drinking.
I guess I have been quite lazy in trying to find an alternative to tap water for the coffee. I went through a phase of trying to use boiled coconut water for my coffee instead, but the taste was beyond foul.
If any UK Peaters have a good source for water, hit me up. Or, if anybody has any other ideas?
You are in the UK, why do you assume your tap water has fluoride? This is not as prevalent as the US...
Hmmm. Not sure. I guess I have always assumed that the UK has as much fluoride as the US in its tap water. Why I have made that assumption is confusing, even to me. It would be brilliant if the tap water wasn't as bad as I'd originally thought. I should look into this really.
jb116 said:post 99953 so what it's the mechanism by which catechins can help slim a person down? Or may be it isn't the catechins at all and its the caffeine. Either way, effects are most important and ncbi shows fat loss effects with this study, although LDL is affected too:
http://www.ncbi.nlm.nih.gov/pubmed/15640470
Parsifal said:post 99960jb116 said:post 99953 so what it's the mechanism by which catechins can help slim a person down? Or may be it isn't the catechins at all and its the caffeine. Either way, effects are most important and ncbi shows fat loss effects with this study, although LDL is affected too:
http://www.ncbi.nlm.nih.gov/pubmed/15640470
Who knows, by raising stress hormones instead of thyroid hormones? Amphetamines can help to slim people as well. There are studies who says everything and its contrary, I almost don't believe in studies anymore. Personal experience and other trustable people's experience has a lot more value to me.
mas said:post 86926 TOP 10 WAYS TO REDUCE FLUORIDE EXPOSURE
Makrosky said:post 87386 Guys, there's many kinds of fluorine molecules. Sodium FLuorine is considered bad, but is the fluoride contained in green tea of this kind ? And also, how it does react with other variables like other tea compounds that might bind it, or the heat for preparing it, etc.
It's not that simple.
It reminds me a post I saw on Chris Kresser blog stating that mercury in fishes is a problem only if the selenium level of that fish is low. If there's a good ratio of selenium/mercury the selenium binds the mercury (with a very strong chemical bond btw) and it becomes harmless. The only "bad" thing is that you'll have less selenium for other uses but you won't get poisoned by the mercury. I hope this is true. Don't know if it's BS or not. But it somehow makes sense.
I'm not saying this is true or not, but it seems the same thing could be happening with Green Tea. For instance, how much iodine vs fluor there's in Green Tea ? We're talking about trace ammounts. Just giving an example.
This is true. I was actually going to post this exact same quote, taken from:I think species difference should be considered here. Rodents are highly sensitive to goitrogenic agents in comparison with humans.
Rats are lacking in high-affinity thyroxine-binding globulin which is present in humans and their plasma half-life of T4 (12-24 hours) is shorter than in humans (5-9 days).
Considering all the parameters, drinking eithet green or black tea should be safe.
And I think that's why Ray hasn't say anything in his book or articles regarding hypothyroidism and its relation to tea consumption.
This is true. I was actually going to post this exact same quote, taken from:
Satoh, K. "Inhibition of aromatase activity by green tea extract catechins and their endocrinological effects of oral administration in rats." Food and Chemical Toxicology (2002)
'In comparison with humans, rodents are highly sensitive to goitrogenic treatment, because of a shorter plasma T₄ half-life (12–24 h) in rats than in humans (5–9 days), which derives from the absence of high-affinity thyroxine-binding globulin in rats that is present in humans.' ―Satoh
Which is another bizarre synchronicity, which seems to happen more often than you'd expect from chance. But besides that, I did find some other good information:
There are scores of common polyphenols found in food, and they all are slightly different. Polyphenols are probably tested mostly on enzymes, more so than for their free radical absorption capacity. Different polyphenols inhibit different enzymes at different concentrations, and every fruit and plant has a characteristic polyphenol profile. Some plants—like tea and cranberries—have more polyphenols than most; and this fact coupled with the naturalistic biases of Asian and Indians—and general nationalistic pride—has led to a considerable pile of data on both tea and soy polyphenols. Tea polyphenols have been shown to powerfully inhibit catechol‐O‐methyltransferase and histidine decarboxylase, and less‐powerful inhibitory effects seen on aromatase—perhaps making this one anti‐estrogenic. But more on topic, the tea polyphenols most likely inhibit the enzyme thyroid peroxidase; this suspicion comes from the in vitro rat data as well as the fact it contains a resorcinol ring:
Divi, Rao L. "Inhibition of thyroid peroxidase by dietary flavonoids." Chemical research in toxicology (1996)
Divi and Doerge had tested a few polyphenols on the enzyme tyroxine peroxidase, and they had found only those with a resorcinol ring were effective inhibitors. And in fact, previous studies have shown resorcinol itself can inhibit this enzyme. The general idea is that this ring acts similar to tyrosine, fits well in the binding site, and upon partial oxidation (− H·) forms a free radical which shifts along the ring in such a way as to react with part of the enzyme; forming a covalent bond.
This is one type of inhibition—the 'suicide inhibitor'—leads to a permanent inactivation of the enzyme, and this can be kinetically measured because this type of inhibition is time dependent (if an enzyme is inhibited the longer it is kept in contract with the polyphenol, or the effect is not reversed by dialysis, then the inhibitor is likely bound permanently to the enzyme.) Polyphenols of type which permanently inhibit include kaempferol, naringenin, and quercetin—but this is not the only type of inhibition. Most polyphenols act as a classic antogonists and simply displace tyrosine from the binding site, preventing iodination and thyroid hormone synthesis. The polyphenol biochanin represents a special case, as this one is actually iodinated:
The four main polyphenols found in tea are the resorcinol‐type, and hence would theoretically be suspected to act as inhibitors of thyroid peroxidase (a.k.a. tyrosine iodinase). The study in the original post on page 1 had used pure catechin, which is actually a fairly minor constituent of tea.⁽¹⁾ A more fair appraisal would have been done with an aqueous green tea extract, perhaps separated by chromatography to remove the fluoride ions—which can be a huge confounder since fluoride ions cause similar thyroid changes in rats.⁽²⁾
View attachment 8114
Fig. 3: Chromatogram showing catechin to be a minor constituent of tea infusion.
Yet this has too been done: Similar results have been observed with a mix of epicatechin (8.5%), epigallocatechin (17.7%), epigallocatechin gallate (32.1%), epicatechin gallate (10.7%), gallocatechin gallate (3.3%) and catechin gallate (1.4%).⁽³⁾ So at least one of these tea catechins could be expected to be a 'suicide inhibitor' of tyrosine iodinase on the basis of its effects in rats and chemical structure. Since brewed tea also contains fluoride ions at ~3‧ppm, this actually makes tea überantithyroid. However, rats are particularly sensitive and these polyphenols can be conjugated in the liver.
'However, total EGC or EC consisted mostly of conjugated forms, whereas total EGCG was constituted mostly of the unchanged form.' ―Chow
If these resorcinol‐polyphenols are sulfated in the #5 or #7 position, they would be expected to be thyroid‐inactive. Such metabolites have been found.
'Accordingly, we identified 3'-O-methyl-(-)-epicatechin-5-O-sulphate and 3'-O-methyl-(-)-epicatechin-7-O-sulphate as the main O-methyl-(-)-epicatechin-sulfates(-)-epicatechin metabolites in humans.' ―Actis-Goretta⁽⁴⁾
Rats would be more sensitive to these thyroidal effects of the resorcinol‐type polyphenols, but there is little reason to think they would be more sensitive to fluoride. For this reason, I still think fluoride is the worst aspect of green tea and think perhaps anyone drinking tea should take boron—which is essentially the only antidote besides perhaps extra calcium (boron and fluoride ion create BF₃ in the plasma, which is then excreted.) And without knowing exactly how 'green tea extract' is made, I would be hesitant to take even that.
'The different mechanisms identified here for TPO inhibition do, however, suggest differences in the potential hazards to humans consuming these compounds. In vivo, flavonoids that are TPO suicide substrates are likely to exert a long-lasting depression of thyroid hormone synthesis because de novo enzyme synthesis is required to restore lost activity. However, the inhibitory effects of flavonoids that are alternate substrate iodination inhibitors would be attenuated by TPO-catalyzed iodination to inactive products, and the effects of reversibly binding inhibitors would be attenuated by extrathyroidal metabolism and excretion.' ―Divi
But the purified polyphenols themselves may not be such a bad thing in humans, and could act to inhibit enzymes that we'd actually want inhibited (i.e. histidine decarboxylase; aromatase) if the proper ones are taken. I am ready to vilify tea—and throw it under the bus—after drinking the stuff I got in the mail for my birthday and then reading more about it, but I think enzyme inhibition events should be taken on a polyphenol‐to‐polyphenol basis. We eat polyphenols all the time; they are highly concentrated in berries and chocolate (i.e. quercitin). As far as I can tell by the binding data, only the soy polyphenols genestein and diadzein have particular affinity for the estrogen receptor—kaempferol coming in a distant third (found in strawberries).
There could be one tea polyphenol worth taking, if it could be separated from both F⁻ the others; but as a caffeinated drink I would place it below coffee and yerba mate. Coffee has an opiate antagonist formed upon roasting (caffeoly quinide) in addition to its high free radical absorption capacity. Yerba mate has caffeine and is much lower in fluoride, although there's probably a few unique molecules lurking in it that could be worth knowing more about.. .
[1] Sano, Mitsuaki. "Simultaneous determination of twelve tea catechins by high-performance liquid chromatography with electrochemical detection." Analyst (2001)
[2] Bouaziz, Hanen. "Fluoride-induced thyroid proliferative changes and their reversal in female mice and their pups." Fluoride (2005)
[3] Satoh, K. "Inhibition of aromatase activity by green tea extract catechins and their endocrinological effects of oral administration in rats." Food and Chemical Toxicology (2002)
[4] Actis-Goretta, Lucas. "Identification of O-methyl-(−)-epicatechin-O-sulphate metabolites by mass-spectrometry after O-methylation with trimethylsilyldiazomethane." Journal of Chromatography A (2012)
[5] Chow. "Phase I pharmacokinetic study of tea polyphenols following single-dose administration of epigallocatechin gallate and polyphenon E." Cancer Epidemiology and Prevention Biomarkers (2001)