There are 500 million molds in one gram of cooked tea. Will drinking too much cooked tea cause cancer? Can Pu-erh tea still be drunk?

China's tea culture can be said to have a long history. There are various types of tea, and how to drink tea is also very particular. Some time ago, Uncle Jiu posted an article about drinking tea. As a result, many people in the comment area had great "opinions" on Pu'er tea:

——Lin Xingkong : The Pu-erh tea in our house is just a decoration, and I have never opened it. I usually only drink green tea from that year, and I think it is healthier than Pu-erh tea.

——He Jing : The longer the wine is put, the more mellow it is, and the tea leaves will be different. If Pu’er tea is left for too long, no matter how the merchants lie and say how good old Pu’er tea is, I will not drink it.

——Uncle Li Jun : Pu-erh tea has been squeezed into brick cakes. It is impossible to judge whether it is good or bad by its appearance. You don’t even know if it is moldy inside. Beware of cancer.

In recent years, there have been rumors that " Pu'er tea contains mold, and one gram of cooked tea contains 500 million mold ", and even that drinking Pu'er tea can cause cancer. As rumors spread, the image of Pu'er tea in the minds of ordinary people plummeted. Many people have doubts about Pu'er tea, and do not know whether this rumor is true or not.

If we want to know the truth, we have to find scientific evidence. Today, Uncle Jiu will give you some popular science.

1. What kind of tea is cooked tea?

Ripe tea is boiled tea? Uncooked tea is raw tea? This is the most common misconception.

In fact, cooked tea refers to a kind of sun-dried green tea from Yunnan big-leaf species in Yunnan Province, which is processed by artificial stacking and fermentation . Ripe tea is not boiled tea, the key step is artificial fermentation. Generally speaking, Pu'er raw tea is made from sun-dried green tea that has not been fermented and processed by artificial fermentation, and it is commonly known as Pu'er cooked tea .

The difference between the two lies in the difference in the production process. Generally, raw tea is spread out, greened, twisted, and dried after picking. After being dried in the sun, it is directly pressed into shape. The cooked tea has to be piled and fermented, then dried , and finally autoclaved. Heap fermentation can speed up the aging of Pu-erh tea and produce a unique flavor.

Raw tea is relatively cold in nature, while cooked tea is relatively mild. The varieties of cooked tea generally include black tea, black tea, and Pu'er cooked tea. When brewed, the cooked tea is darker in color, showing a brownish red color, and has a unique aged taste. fragrant.

2. Is cooked tea really moldy and carcinogenic? Experimental results released

Ripe tea is really criticized by the rumors, one is that the mold exceeds the standard, and the other is that it contains the carcinogen aflatoxin?

In order to explore the truth of the rumors, the Guangdong Provincial Center for Disease Control and Prevention conducted random inspections of various types of Pu'er tea on the market to detect the content of aflatoxin and other mycotoxins. The specific process is as follows:

[Sampling samples] : 40 brands whose origin is mainly in Yunnan, some are bulk products, the price ranges from high to low, and the years cover 1 to 30 years, a total of 148 samples.

[Detection method] : Determination by the first method of "GB/T5009.23-2016 Determination of aflatoxin B1, B2, G1, G2 in food" isotope dilution liquid chromatography-tandem mass spectrometry, LOD=0.03μg/kg.

[Aflatoxin detection results] : Among the 148 samples sampled, 3 samples were detected with aflatoxin B1 , and the detection values ​​were 0.26μg/kg, 0.407μg/kg, and 0.56μg/kg.

The maximum value is similar to the minimum limit ( 0.5μg/kg ) for infant formula food stipulated in GB2761-2011 "National Food Safety Standard Limits of Mycotoxins in Food" , but far lower than the limit of 10μg/kg for rice and the limit for peanut oil 20 μg/kg .

【Detection results of other mycotoxins】 : No other mycotoxins were detected.

【Experimental conclusion】 : According to the test results, the claim that Pu'er tea causes cancer is not established, and its health risk is very low.

In addition, a literature search on the carcinogenicity of Pu’er tea revealed that most of the molds isolated from aged Pu’er tea were Aspergillus niger, Penicillium, and Mucor, which were normal bacteria in the fermentation process, and Aspergillus flavus was not present. Among them .

Therefore, the two rumors about Pu'er tea are not true.

3. Research from Jiaotong University: Drinking Pu'er may reduce fat

Jia Wei, Zhao Aihua and others from the Sixth People's Hospital Affiliated to Shanghai Jiaotong University published a research paper in Nature Communications, a sub-journal of the top international academic journal Nature. The study shows that Pu'er tea may be beneficial to regulate blood lipids.

The study confirmed that Pu'er tea contains an active substance called theabrownin , which can regulate the body's intestinal flora and bile acid metabolism, thereby reducing hypercholesterolemia.

Theabrownin is one of the components with the highest active content in Pu- erh tea . It helps to adjust the structure of the intestinal flora in the human body and significantly reduces the abundance of bacteria related to the activity of bile salt hydrolase (BSH). Further studies have shown that the activity of BSH is significantly decreased, which can promote the production of bile acids in the liver and excretion of feces, and ultimately reduce the production of fat.

4. If you love tea, you need to know 5 things

Tea is deeply loved by the people, but there are some precautions for drinking tea. If you drink tea in the wrong way, it will increase your risk of disease. If you love tea, it is recommended to understand the following 5 points.

1. Do not drink hot tea

Some people like to make tea with freshly boiled hot water and drink it right away, especially Gongfu tea. In fact, drinking tea that is too hot will burn the esophageal mucosa and increase the risk of esophageal and gastric cancer . The most suitable temperature for drinking tea is 50°C. Boiling water can be used for brewing, but wait for a while before drinking.

2. Drink less strong tea

The content of tannic acid and caffeine in strong tea is relatively high. Tannic acid can hinder the absorption of iron. Excessive intake of caffeine may cause discomfort such as rapid heartbeat and palpitations. Therefore, when brewing, pay attention to controlling the amount of tea leaves and drinking less strong tea.

3. Do not drink tea on an empty stomach

Drinking tea on an empty stomach will increase the stimulation of caffeine and tannic acid on the stomach. Some active substances in tea will combine with the protein in the stomach to promote gastric acid secretion, which is not conducive to the health of the stomach.

4. Do not drink tea to hangover

Some people get drunk and want to hangover by drinking strong tea, which is actually wrong. ,

When drunk, people's heart rate and breathing speed up, and the theophylline and caffeine contained in strong tea will also speed up the heart rate. Not only will it not have the effect of hangover, but it will increase the burden on the heart.

5. Drink less sugar-sweetened tea drinks

When buying tea drinks, it is recommended to choose sugar-free or low-sugar ones. If conditions permit, it is best to make tea yourself. Some tea beverages are packed with tea, but put a lot of sugar, which not only makes the tea lose its original flavor, but also makes the human body consume excessive sugar, which is not good for health.

All in all, the claim that Pu'er tea causes cancer is not established. When drinking tea, we should pay attention not to drink hot tea, drink less strong tea, and not drink tea on an empty stomach, and drink tea in the correct way to keep our body healthy.

References:

[1] Liao Yuting. "Puer tea carcinogenic theory" is not established! ——Interview with Zhang Yonghui, director of Guangdong Provincial Center for Disease Control and Prevention[J]. Consumer Reports, 2018(2):1.

[2] Xu Jingyi, Shao Wanfang, Zhang Jun, et al. Isolation and identification of main molds in Puer tea (cooked tea) [J]. Food Industry Science and Technology, 2010(12):110-114.

[3] The latest research from Shanghai Jiaotong University shows that Pu'er tea can reduce the three highs, treat obesity, and reveal the specific mechanism behind it, Biological World, 2019-11-03

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