|"Pesticide pollution: Chinese tea may not be safe to drink," this is what you could read on the website of Greenpeace in 2012, already and obviously this has not changed over the last 2 years | read more|
Apropos "Guess where it's from!", if I had to guess, I would say that 99% of the black, green and olong tea extracts in green tea, fat burner, pre-workout, anti-oxidant, and other commercially available supplements will be from China. The fact that cadmium (Cd), inorganic and thus toxic chromium (Cr) and lead (Pb) were present in samples from Zhejiang, Fujian, Yunnan, Anhui, Hunan, Guangdong and Taiwan is relevant for ~95% of the SuppVersity readers.
You think that's an old hat? Well, what about the perfluorinated compounds (PFCs) the researchers, who are by the way working for the China Ministry of Agriculture and thus certainly not interested in making Chinese tea look like a poisonous swill, detected in all samples. The concentration of these emerging and ubiquitous organic pollutants in the samples varied. In view of the already established negative health effects of which Eriksen et al. (2009), Corsinia et al. (2012) and Posta et al. 2012) write that they encompass...
Would all commercially available teas have to be labeled like this? A previous study which found also Aluminum & Arsenic in tea bags, would suggest just that | read more
- increased risk of high cholesterol
- increased risk of cancer,
- liver dysfunction,
- disruption of the immune system,
- disturbances of the endocrine (=hormone) system,
- developmental delays, and
- fertility issues
PFCs are everywhere: Due to their toxic effects in humans and other organisms, PFCs were added to the list of banned chemicals in the Stockholm Convention on Persistent Organic Pollutants in 2009 (Ma and others 2012). Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) have been detected in animals and water samples from rain, river, wastewaters, and sea. They are present in plants and crops, including all twenty foodstuffs that were examined in 2004 in Great Britain by Gem et al. in 2006. PFCs are present in wheat, oats, potatoes, and maize (Stahl. 2009) and their concentration is the highest in plants / crops that grow in or close to the ground - including the peeled edible parts of carrots, potatoes, and cucumbers.If you look at the maximal heavy metal content (individual circles in Figure 1) you will see that eventually, even the high manganese content of up to 240mg/100g could become problematic.
And while the combination of cadmium, lead and chromium is etching away your brain and nervous system, the PFCs, which were detected in form of PFOS in only 6 samples and in form of PFOAs in 33 samples, will launch an attack on your endocrine system. Unfortunately, there is no reliable information on whether or not chronic exposure to teas with 250ng/kg dw of this endocrine disruptor will or will not have permanent negative effects on your health.
|Table 1: Contents of PFOA and PFOS according to origin (left) and type (Zhang. 2014)|
- Dobson, Allison W., Keith M. Erikson, and Michael Aschner. "Manganese neurotoxicity." Annals of the New York Academy of Sciences 1012.1 (2004): 115-128.
- Ma, Jin, et al. "State of polybrominated diphenyl ethers in China: An overview." Chemosphere 88.7 (2012): 769-778.
- Stahl, T., et al. "Carryover of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) from soil to plants." Archives of environmental contamination and toxicology 57.2 (2009): 289-298.
- Zheng, H. et al. "Analysis of Trace Metals and Perfluorinated Compounds in 43 Representative Tea Products from South China." Journal of Food Science (2014). Accepted Manuscript. doi: 10.1111/1750-3841.12470