Drinking tea can reduce the risk of stroke? Why are there rumors that it can cause cancer? An article to give you popular science!

The culture of growing and drinking tea in China has a long history. According to relevant research, China is the starting point of the tea culture in the world. Even now, many young people like to drink a cup of tea in their spare time.

　　They found that the aromatic smell in tea has the magical effect of refreshing and increasing vitality. Moreover, health experts have also said that drinking tea does have certain benefits to health.

　　Not only that, but related studies have pointed out that drinking tea can also reduce the risk of stroke!

　　Stroke must be familiar to everyone. It is one of the cardiovascular and cerebrovascular diseases with high incidence in middle-aged and elderly people. Its scientific name is "stroke" in clinical practice .

　　According to the current clinical information, the causes of stroke are quite complex, including genetics, age and vascular aging, three high diseases, unhealthy life and eating habits , etc.

　　The Chinese research team has conducted related investigations and research on tea. Since the middle of 2000, the research team has focused on people aged 50 to 74 , and the number of volunteers has reached 365,682. At the same time, the research team also paid attention to people who had not had a stroke before, and followed up for a total of about 11.4 years .

　　Among these volunteers, 10,053 stroke patients were identified . The research results show that people who drink 3-5 or 4-6 cups of tea a day have a relatively lower risk of stroke, which can be reduced by about 32% . The reason for this is that tea contains many beneficial ingredients, including tea pigment, theophylline, and tea polyamines , etc. These beneficial ingredients have the effect of maintaining blood vessels.

　　Of course, this study cannot point to an absolute equivalence between stroke and tea. As mentioned above, there are many high-risk factors for stroke. This experiment did not exclude many high-risk factors, and the age of the survey is the high-risk age for stroke . Therefore, this experiment can only show that tea has the effect of health preservation, but it does not mean that it can directly prevent stroke.

　　So here comes the question, since tea has the effect of health preservation, why are there rumors that it can cause cancer?

　　In 2019, the Chinese research team also conducted a follow-up survey on more than 500,000 Chinese people who drank tea. The results showed that compared with those who drank tea less than once a week, those who drank more than 4g of tea per day had a significantly higher risk of cancer. The increase can reach about 26% , especially the incidence of gastric cancer and lung cancer , which has increased to about 29% and 62% .

　　However, the research team also clearly pointed out that the reason for this conclusion does not directly explain the relationship between tea and cancer. Because some people in this group also have other bad habits, such as smoking and drinking .

　　Moreover, they tend to think that drinking tea can offset the harm caused by tobacco and alcohol, so they are prone to unscrupulous smoking. After adjusting the amount of smoking, the association between drinking tea and cancer becomes weaker, so drinking tea causes cancer so far, and there is no clear conclusion.

　　However, there may be a close relationship between tea drinking and esophageal and gastric cancer. However, it's not about the tea or the tea itself, but the temperature of the tea. Many Chinese people are used to drinking hot tea, thinking that only when it is hot can the aroma of tea be stimulated.

　　And this will just cause damage to the mucous membrane of the digestive tract, which in turn increases the chance of canceration. The World Health Organization has already discovered this, and has included food or water above 65°C in category 2a carcinogens.