7 replies to this topic

[Nathanial]

Does anyone know how serious the problem of soil pollution is regarding human consumption of various teas? Yesterday I drank 2 bags of cheap, Chinese non-organic green tea around 20 minutes after waking, while fasted, and within 10 minutes started feeling significantly worse for wear, and then worse again after 30 minutes. Today I've switched to fresh coffee beans and do not feel so horrible as I did yesterday. Can anyone accurately interpret the available evidence and offer forth some advice? The internet is awash with sordid tales of Chinese soil/air/land/river pollution, maybe that is the problem?

 

Fe, Zn, Cu, Pb and Cd in Tea Grown and Marketed in Kenya; A Quantitative Assessment

 

International Journal of Environmental Protection 06/2013; 3(6):24-30.

ABSTRACT Accurate quantitation of levels of essential and non-essential elements in tea is of great importance as they are directly related to health and disease. In this study, levels of Iron (Fe), Zinc (Zn), Copper (Cu), lead (Pb) and Cadmium (Cd) in tea grown and marketed in Kenya were quantified by Flame Atomic Absorption Spectroscopy (FAAS). In unprocessed tea, the levels were found to range between 54.6 and 123.3 µg/g for Fe, 15.4 and 37.5 µg/g for Zn, 10.3 and 14.8 µg/g for Cu, 0.12 and 0.28 µg/g for Pb and 10.0 and 27.1 μg/kg for Cd whereas in black tea, the levels ranged between 81 and 369 µg/g for Fe, 17.1 and 44.9 µg/g for Zn, 9.0 and 17.8 µg/g for Cu, 0.12 and 0.41 µg/g for Pb and 9.1 and 40.0 µg/kg for Cd. The general accumulation pattern of these elements was established to be Fe > Zn > Cu > Pb > Cd in both unprocessed and black tea. All tea samples had metal contents within the Maximum Permissible Concentrations (MPC) set for tea, hence safe for consumption.

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A copy and paste from wikipedia:

 

"

Aluminum and heavy metals

Further information:

Tea drinking accounts for a high proportion of aluminum in the human diet. The levels are safe, but there has been some concern that aluminum traces may be associated with Alzheimer's disease. A recent study additionally indicated that some teas contained possibly risky amounts of lead (mostly Chinese) and aluminum (Indian/Sri Lanka blends, China). There is still insufficient evidence to draw firm conclusions on this subject.^"

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Is green tea worth drinking? Apologies for the sensational topic title, mods can edit that if they want.

Edited by Nathanial, 13 July 2014 - 08:30 AM.

[8bitmore]

Of course green (and especially white) tea is worth drinking but perhaps more so than with other food products getting an organic variety is essential - I use Clipper's Organic White tea often and feel fine on it. The dose makes the poison though - what is too much varies from day to day and sometimes I function better on a good cup of coffee.

[niner]

Tea accumulates minerals from the soil, so just being labeled "organic" doesn't guarantee you that the levels of aluminum and transition metals are low, or even safe.   All you have to do to get an organic label is not use biocides.  I don't think there are any requirements regarding the use of soil from toxic waste dumps or whatever.  Even if there are, some soils contain all these metals naturally.   This topic has been discussed a lot here.  You're generally better off with high quality teas, while cheap teas may be more sketchy.  I'd like to think that a responsible producer would have their teas tested, but I doubt that a boutique brand could afford to do that, even though they might have the best tea.   Along with using a high quality tea, white tea is best, and black tea tends to be the worst, for a given soil.

 

Keep in mind that there is a ton of epidemiology that says green tea is good for you overall.    I don't think it's crazy to want "better than good"-  Maybe green tea would help you stave off some problem into your nineties, but we want to stave them off  permanently.

[Razor444]

I've been brewing from bags. To wit:

 

'Still, the study found that there was no real prospect of a health concern from the lead. The liquid portions of the teas that were brewed and tested contained very little if any of the metal, Dr. Cooperman said.

 

"The majority of the lead is staying with the leaf," he said. "If you’re brewing it with a tea bag, the tea bag is very effectively filtering out most of the lead by keeping those tea leaves inside the bag. So it’s fine as long as you’re not eating the leaves."'

Edited by Razor444, 13 July 2014 - 04:15 PM.

[timar]

Tea accumulates minerals from the soil, so just being labeled "organic" doesn't guarantee you that the levels of aluminum and transition metals are low, or even safe.   All you have to do to get an organic label is not use biocides.  I don't think there are any requirements regarding the use of soil from toxic waste dumps or whatever.  Even if there are, some soils contain all these metals naturally.   This topic has been discussed a lot here.  You're generally better off with high quality teas, while cheap teas may be more sketchy.  I'd like to think that a responsible producer would have their teas tested, but I doubt that a boutique brand could afford to do that, even though they might have the best tea.   Along with using a high quality tea, white tea is best, and black tea tends to be the worst, for a given soil.

 

People often seem to confuse contamination issues from biocides in conventional agriculture (which you can largely avoid by buying organic) with toxicity issues due to naturally occuring toxins like heavy metals in the soil or mycotoxins from molds. I agree that it is important to buy organic tea, as the use of biocides is often poorly regulated in tea-producing countries. However, when it comes to undesirable trace elements (particularly aluminum and fluoride), the quality grade is most important. The more delicate the tea (e.g. white tea or first-flush darjeeling) the younger the leaves when harvested and the lower the amount of trace elements accumulated from the soil. The only reason why black tea contains more trace elements on avarage is that most black tea is of the low-quality bagged variety made from "dust" grade tea, the oldest and most tannic leaves ground into fine particles. This gives also the strongest taste and colour, due to the higher content of polyphenols and higher surface area. The good news is that the phenolic monomers we are after have a much higher water solubility than the trace elements contained in the cell wall and vacuole, where they are bound to fiber and largely rendered insoluble. The more processed and finely ground the tea leaves are, the more the cells become structurally damaged and the more aluminum and fluoride leaches into the water.

 

Keep in mind that there is a ton of epidemiology that says green tea is good for you overall.    I don't think it's crazy to want "better than good"-  Maybe green tea would help you stave off some problem into your nineties, but we want to stave them off  permanently.

 

I agree with the first part. However, it seems to me that too many people in this forum let the perfect be the enemy of the good. Like immortalists not caring to eat a healthy, calorie-restrained diet because doing so they would only gain a "few scant" extra years in good health, while they are longing for a scientific breakthrough that would enable us to "permanently fix" aging. Unfortunately, this eagerly anticipated breakthrough will probably never arrive during their lifetime and so they end up wasting the best (and most enjoyable!) opportunity we have thus far to stave off age-related diseases and gain precious health-span. In my opinion one should always give priority to what we know to be "good" and only then turn to speculative concerns on what could be "better". So, if the epidemiological evidence overwhelmingly shows that tea is good for you, it is unreasonable to avoid tea because of speculative concerns about trace element toxicity. It is perfectly reasonable, though, to choose high-quality tea over cheap tea bags based on these concerns. And of course, considering age-related diseases, it would be unreasonable to expect from tea or any food to "stave them off permanently", or to be worried about its hypothetical long-term toxicity at the age of 150

Edited by timar, 13 July 2014 - 04:21 PM.

[timar]

I've been brewing from bags. To wit:

 

Lead and other heavy metals in tea are pretty much a non-issue, as the levels are generally low enough not to be of any concern. The trace elements one should be concerned about, though, are aluminum and flouride, both occuring in the mg/l-range in brewed tea (as opposed to ng/l with lead). As I have explained above: it is best to avoid cheap bagged tea and to choose high quality-grade large-leaf varieties, which are generally not available as tea bags.

Edited by timar, 13 July 2014 - 04:27 PM.

[8bitmore]

Tea accumulates minerals from the soil, so just being labeled "organic" doesn't guarantee you that the levels of aluminum and transition metals are low, or even safe.   All you have to do to get an organic label is not use biocides.  I don't think there are any requirements regarding the use of soil from toxic waste dumps or whatever.  Even if there are, some soils contain all these metals naturally.   This topic has been discussed a lot here.  You're generally better off with high quality teas, while cheap teas may be more sketchy.  I'd like to think that a responsible producer would have their teas tested, but I doubt that a boutique brand could afford to do that, even though they might have the best tea.   Along with using a high quality tea, white tea is best, and black tea tends to be the worst, for a given soil. [...]

 

I get the point about high quality teas (best chosen for growing in virgin soil..) being better than random organic varieties, but no one is saying that buying organic teas should entail going cheap. I mentioned Clipper's variety of white tea I should probably be drinking one grown in India - at least according to http://www.hindawi.c...13/370460/tab4/ - all the same I still think big meta review's such as " Higher antioxidant and lower cadmium concentrations and lower incidence of pesticide residues in organically grown crops: a systematic literature review and meta-analyses" brings a sufficient amount of credibility behind organic food sources that drinking organic tea should certainly be on the list of fundamentally good consumer choices. Pair that organic choice with spending enough money to get a high quality tea and I think you have a winning proposition.

[Nathanial]

 

I've been brewing from bags.

 

Lead and other heavy metals in tea are pretty much a non-issue, as the levels are generally low enough not to be of any concern. The trace elements one should be concerned about, though, are aluminum and flouride, both occuring in the mg/l-range in brewed tea (as opposed to ng/l with lead). As I have explained above: it is best to avoid cheap bagged tea and to choose high quality-grade large-leaf varieties, which are generally not available as tea bags.

 

 

Thanks for the reassurance regarding the heavy metal issue. The bags I used were from Clipper, if anyone wants to perform an experiment on themselves, believing that I'm exaggerating and/or hysterical. They were cheap and very nasty.