Suddenly The question and article "How to see 'Pu'er tea causes cancer'" have been ignored. In fact, this problem has appeared for several years. The legend of "Pu'er tea causes cancer" is that there is aflatoxin in Pu'er tea, and the Pu'er tea industry has been trying to prove that "there is no aflatoxin in Pu'er tea".
Here are some facts about this problem:
1、 The production of aflatoxin requires two factors: "Aspergillus flavus" and "suitable conditions". The production process of Pu'er tea is not conducive to the production of aflatoxin in these two aspects. In other words, the Pu'er tea industry "proves" that there is no aflatoxin produced in the production process of Pu'er tea, which does not mean fraud.
2、 It is true that Pu'er tea (in fact, there is black tea recently) has been detected with aflatoxin. The most famous is the test results of 70 wet puer in a market in Guangzhou released by the Guangzhou Center for Disease Control and Prevention in 2010, which not only detected, but also 8 samples exceeded 5ppb (1 ppb is one part of a billion, i.e. micrograms/kg). Since then, other similar tests have also detected aflatoxin in some Pu'er tea. In other words, it is not uncommon to detect aflatoxin in Pu'er tea. Recently, there are reports of aflatoxin detection in black tea. It is not clear whether other teas are "not detected" or "not detected".
3、 The previous articles 1 and 2 are not contradictory. The Pu'er tea industry has proved that "no aflatoxin is produced in the production process of Pu'er tea". In addition to the "production process", aflatoxin may be introduced (not necessarily produced) into raw materials and subsequent storage. For example, 70 samples tested by the Guangzhou Center for Disease Control and Prevention were all "Pu'er in wet warehouse". The so-called "wet warehouse" is actually intended to store tea in a warm and humid warehouse to make it more quickly undergo "post fermentation". In essence, it is similar to the "old" treatment in collectibles. In such an environment, there is not only the possibility of tea being polluted by aflatoxin, but also the possibility that aflatoxin and toxin already exist in the warehouse, polluting the product during storage. In addition, due to climate, planting conditions and other reasons, the raw materials may be contaminated with aflatoxin (more common in corn). Whether there is a similar situation in tea has not been reported at present.
4、 From the "detection of aflatoxin" to deduce that "drinking Pu'er tea causes cancer", it is a typical rogue behavior of talking about toxicity without dose. The concentration of aflatoxin in food is very low, and it is impossible to cause acute poisoning. Its main harm is that long-term intake will increase the risk of liver cancer. Among the various types of aflatoxins, B1 Is the most carcinogenic. According to the results of epidemiological investigation, scientists concluded that aflatoxin B1 The relationship between intake and liver cancer risk of one NAK aflatoxin B1 For every 10 million non hepatitis B patients, approximately one case of liver cancer is added every year; For hepatitis B patients, there are three more cases per million people every year. The United States stipulates that the total amount of Aspergillus flavus in all foods except dairy products shall not exceed 20ppb (Relatively speaking, China's standards are stricter, see the following section six Article). If you eat half a kilogram of peanuts, rice, corn, soybeans and various nuts every day B1 The content reaches the upper limit 20ppb The total amount is ten Micrograms. At adult weight sixty Kg, the intake per kg of body weight is about one hundred and seventy Nak. For non hepatitis B patients, the risk of liver cancer increases every year six 1/10000; For hepatitis B patients, it is equivalent to an increase every year two 1/1000 ” 。
5. Connected to No four Article. At present, most of the aflatoxins detected in tea are 5ppb Below, only a few exceed this amount. We press 10ppb To calculate, the average person drinks a few grams of tea every day ten In gram, the total amount of aflatoxin contained in it is zero point one Micrograms. Moreover, the aflatoxin in grain and oil is directly eaten into the body, and the aflatoxin is difficult to dissolve in water, not easy to dissolve into tea water. In fact, the amount of aflatoxin drunk into the body is lower than that in tea. Even if it is all soaked in tea, zero point one The microgram content is only equivalent to the total amount of food intake calculated above 1% 。 in other words, If you are worried that drinking Pu'er tea will cause cancer, the risk of cancer caused by eating is higher than it one hundred Times!
6、 In fact, aflatoxin is almost unavoidable in agricultural products. No country in the world can regard "no aflatoxin" as the safety standard of grain and oil. The current Chinese standards are: Peanuts and corn and their products, limited to 20ppb ； Rice and its products, limited to 10ppb ； For wheat, soybeans, nuts and their products, the limit standard is 5ppb 。 This standard is not too low internationally.
7、 The national standard does not set the limit of aflatoxin in tea, which is not a "lack of legislation", but after risk assessment and comprehensive consideration of "possible aflatoxin content" and "daily tea consumption of consumers" in tea, it is believed that aflatoxin in tea will not harm public health, so "it is not necessary to set standards".
In short, Pu'er tea and even other teas may indeed contain aflatoxin due to the existence of raw materials, storage and other links. However, its content is low, not as high as the possible content in various cereals and oils. Based on its "possible content" and "daily consumption", the aflatoxin in tea is not worth worrying about at all.
"Carcinogenesis" is a keyword with the ability of "attracting demands". The hype of "Pu'er tea causes cancer" is typical of "talking about toxicity without dose". If the "cancer risk" of Pu'er tea needs to be worried, what should we do about the food and oil, pig, beef and mutton, and sunlight, which are much higher than the "cancer risk" of Pu'er tea?
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