Whether pu 'er tea causes cancer

The 2017-09-30 health

      "Can you prevent cancer or cancer by drinking tea?" by fang zhouzi, a popular science scholar. The report of the puer tea association of yunnan province said fang zhouzi's remarks greatly damaged the reputation of yunnan province's pu 'er tea industry, and will Sue fang zhouzi for a loss of 6 million yuan. If the case can be fought, it will be a great opportunity for the public to know whether pu 'er tea is carcinogenic or not. However, if there are some basic questions about pu 'er tea, some preliminary judgment may be obtained.

      First, whether the market of pu-erh tea contains aflatoxin, is it a normal? Second, how many of these flavonoid levels of pu-erh tea are consumed, and how many of them enter the body, and whether or not aflatoxin can cause cancer? Third, what are the factors that influence aflatoxin in life?

      Whether the city sells pu 'er tea contains aflatoxin

      Your first question, it's all the fact that in 2010 the guangzhou center for disease control and prevention researchers guangzhou court selectiving examination of 70 samples of pu 'er tea, were all detected aflatoxin, there are eight pieces of aflatoxin content beyond the aflatoxin limit stipulated by the grain standard of China (5 micrograms/kg).

      However, some researchers believe this is the result of inaccurate market sampling. 2010 guangzhou selectiving examination are inferior puer tea samples, but in 2014, guangzhou liwan district center for disease control and prevention from tea wholesale market bought 140 random samples of pu 'er tea, eight of the detected aflatoxin B1, detection rate of 5.7%. In other words, if random sampling is detected, the sample of pu 'er tea without aflatoxin is the majority (94.3%). A random sampling of a product's quality results is more objective and more realistic than a sample of a certain type of product (best or worst).

      Aflatoxin is a recognized carcinogen, which is not disputed. The key is how much of the dose is going to cause cancer, and there's no epidemiological data, just animal test results. Aflatoxin B1 was 10 micrograms per day for oral cancer in rats, and the teratogen was 1 4mg/kg (pregnant rats were given in the abdominal cavity). Aflatoxin can also cause the chromosomal aberration of animal and plant cells, which can also cause the proliferation of epithelial cells in animal bile duct and spleen, kidney, testes, brain and nervous system lesions. Aflatoxin also has the characteristic of suppressing immunity, which may be related to the inhibition of protein synthesis.

      The principle of dose-determining toxicity should be adhered to

      Based on the principle of dose decision toxicity, aflatoxin B1 in rats (SD rats, weight about 150 g) oral dose of 10 micrograms per day of cancer, time is a few months (3 ~ 6 months), for a 60 kg weight, carcinogenic dose is equivalent to 2.5 mg/day, whether you need for 3 ~ 6 months, it remains to be proved.

      But, in 2010, the centers for disease control and detection of aflatoxin B1 in guangzhou is the highest content of 8.52 micrograms/kg (tea), carcinogenic dose in rats corollary to people is 2.5 mg/day, check out than the market 8.52 micrograms/kg 293 times higher than that of the amount of (tea), but also to drink a kilogram of puer tea, and aflatoxin absorbed by people, all of them to reach 8.52 micrograms of aflatoxin. In addition, 293 times continuous drinking of pu 'er tea can only be carcinogenic in March and June. Obviously, this can't happen in real life.

      People eat food every day in life there are many, pu 'er tea was part of a few food containing aflatoxin actually has a lot of, such as peanuts, corn, rice, wheat, beans, nuts, meat, milk and dairy products, aquatic products contain aflatoxin, of which the highest content of peanut and corn. Therefore, even if aflatoxin is harmful to people, it can't be the yellow aspergillus in pu 'er tea alone.

      Several factors inhibit the production of aflatoxin

      In addition, there are several factors that inhibit aflatoxin. One is that chlorophyll in green leafy vegetables can inhibit aflatoxin, and people eat a lot of green vegetables every day, which inhibits the carcinogenic or pathogenic effects of aflatoxin. The second is the modern production of pu 'er tea, through a way to call heap "w", this is a solid state fermentation process, which involves more microbial species, such as aspergillus Niger, aspergillus and both can inhibit the growth of aflatoxin, and contains some of the compounds in tea such as tannin, caffeine can inhibit the generation of aflatoxin. The test showed that when the caffeine content was 0.5mg/ml, 86% of aflatoxin was suppressed, and aflatoxin was completely inhibited when 2mg/ml was reached.

      Puer tea in the process of production, therefore, is not so easy to produce aflatoxin, only in the storage, transportation, storage may produce some aflatoxin, and with the restriction of various factors, only by aflatoxin content of pu 'er tea is difficult to separate and direct cause human cancer and poisoning. But now that indeed some puer tea in the detection of aflatoxin, this also for the food safety supervision put forward the more strict requirements, also for the public to carry a wake, when to buy and drink tea, should buy those through formal channels to produce and sell high quality products, quality control, which could reduce aflatoxin may cause the damage of puer tea.