|Would all commercially available teas have to be labeled like this?|
The corresponding experiment, the results of which were published in the peer-reviewed open-access Journal of Toxicology in October 2013, already, addresses the increasing concern about contamination of foodstuffs and natural health products. With the emphasis being on foodstuff and health, it's only logical that tea, or more precisely all currently available off-the-shelf varieties of black, green, white, and oolong teas sold in tea bags were used for analysis in the said study.
So what did the researchers do?
Schwalfenberg, Genius (no joke, the 2n author is a real 'Genius by name') and Rodushkin conducted a three-step analysis in the course of which they analyzed the content of previously identified tea contaminants like aluminum, fluoride, mercury, lead, cadmium and arsenic (Fujimaki. 2004; Lung. 2008; Wang. 2008; Alvarez-Ayuso. 2011; Tan. 2012) in commercial tea preparations.
|Table 1: There are not just bad, but also healthy minerals in tea!|
- Cardiovascular benefits - When we are talking about health in general and heart health in particular, most people will think of green tea. That's pretty unfortunate, because there is ample research for all varieties of teas that they can lower blood lipids, provide "clean" and thus heart healthy energy, and exert antithrombotic and anti-hypertensive effects.
- Anticancer effects - Despite the fact that the anti-cancer effects have mostly observed in in-vitro studies, there is plenty of epidemiological evidence that tea drinkers have a lower cancer risk, than the average coke guzzler (not necessarily breast cancer, though ➫ SuppVersity Facebook News).
- Metabolic syndrome - While more recent studies clearly suggest that the active weight loss effects of tea, in general, and green tea, in particular, have been totally overblown, there is still a host of controlled trials, where adding tea (not necessarily green tea) improved the effects of a energy restricted diet. Compared to the rodent trials which are still fueling the myth of the potent thermogenic effects of (green) tea, the real world results in human beings are however downright disappointing.
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- Other beneficial effects - Under "Miscellaneous Effects", Schwalfenberg et al. also list the nephropotective effects of green tea, which could come very handy if you guzzle mercury contaminated green tea, everyday (unfortunately, mercury is your least problem with tea), the anti-depressive researchers have observed in people consuming 4+ cups of tea per day and the hitherto unconfirmed hypothesis that tea drinkers are (better) protected against Alzheimer’s and neurological decline.
Organic is not better than regular tea
To obtain a dataset that would be as comprehensive, accurate and practically relevant as possible the authors bought 30 different organic and non-organic white, green, oolong, and black teas from the the shelves of Canadian supermarkets and analyzed (a) the "raw" tea leaves (LEAF), (b) tea that had been steeped for 3-4 minutes (3MIN), (c) tea that had been steeped for 15–17 minutes (15MIN).
"Public health warnings or industry regulation indicated" -- It sounds pretty fearmongering and I would not have used it as a subheading right beneath the introduction, if the statement "Public health warnings or industry regulation might be indicated to protect consumer safety." (Schwalfenberg. 2013) was no literal citation from the conclusion of the paper I have here right in front of me.
|Table 3: Levels of mercury (Hg), lead (Pb), aluminum (Al), arsenic (As) and cadmium (Cd) in tea infusions after 3-4 or 15-17 min of brewing; all values in µg/L (Schwalfenberg. 2013)|
"All teas contained significant amounts of aluminum. Tea leaves contained from 568 to 3287 ng/g of tea. All brewed teas steeped for 3 or 15 minutes contained detectable levels of aluminum. The range was 1131µgm/L to 8324µgm/L steeping for 3 minute and 1413µgm/L to 11449µgm/L steeping for 15 minutes. Only 2 teas had levels above acceptable limits at 3 minutes of brewing but 6 of the teas had levels greater than the upper acceptable daily limit of 7000µgm/L. Clearly letting tea steep for longer than 3 minutes is not advisable. Two of the organic green teas had levels above 10,000µgm/L brewed for 15 minutes."In view of the fact that tea is by far not the only aluminum source you are expose to, the high levels of this toxic metal that easily accumulates in the body should be reason enough not to brew your tea - especially not organic tea - for more than 3 minutes.
Organic tea is a worse offender than regular
If you take a look at the amount of lead in the various tea samples it becomes even more obvious that "organic" tea is not necessarily better for your organs, as well. This is particularly true for the best-sellers green and black tea, both of which contain significantly more lead in the "organic" vs. "regular" variety.
|Table 4: Toxicant levels according to origin; Pb: lead, Cd: cadmium, Al: aluminum, As: arsenic (Schwalfenberg. 2013)|
"...[a]ll tea leaves had detectable levels of cadmium. 21 teas had detectable levels after 15 minutes brewing while only 18 teas had detectable levels after 3 minutes brewing suggesting that there is further leaching of this toxicant into the water over time. [As the overview in Table 4 already suggests] the highest level was 0.067µgm/L found in standard oolong tea from China." (Schwalfenberg. 2013)Not listed in the tables are the levels of tin, barium, antimony and thallium, which were detected in all tea samples, but at levels of which the authors state that they don't have to be "considered to be of concern" (Schwalfenberg. 2013).
- Álvarez-Ayuso, E., Giménez, A., & Ballesteros, J. C. (2011). Fluoride accumulation by plants grown in acid soils amended with flue gas desulphurisation gypsum. Journal of hazardous materials, 192(3), 1659-1666.
- Hayacibara, M. F., Queiroz, C. S., Tabchoury, C. P. M., & Cury, J. A. (2004). Fluoride and aluminum in teas and tea-based beverages. Revista de Saúde Pública, 38(1), 100-105.
- Lung, S. C. C., Cheng, H. W., & Fu, C. B. (2007). Potential exposure and risk of fluoride intakes from tea drinks produced in Taiwan. Journal of Exposure Science and Environmental Epidemiology, 18(2), 158-166.
- Steinmann, J., Buer, J., Pietschmann, T., & Steinmann, E. (2013). Anti‐infective properties of epigallocatechin‐3‐gallate (EGCG), a component of green tea. British journal of pharmacology, 168(5), 1059-1073.
- Tan, Z., & Xiao, G. (2012). Leaching characteristics of fly ash from Chinese medical waste incineration. Waste Management & Research, 30(3), 285-294.
- Schwalfenberg, G., Genuis, S. J., & Rodushkin, I. (2013). The Benefits and Risks of Consuming Brewed Tea: Beware of Toxic Element Contamination. Journal of toxicology, 2013.
- Wang, X. P., Ma, Y. J., & Xu, Y. C. (2008). [Studies on contents of arsenic, selenium, mercury and bismuth in tea samples collected from different regions by atomic fluorescence spectrometry]. Guang pu xue yu guang pu fen xi= Guang pu, 28(7), 1653-1657.