Original Technology Daily Technology Daily
◎ Science and Technology Daily reporter Guo Guozhong and correspondent Jiang Wenrong
A few days ago, some domestic media interviewed experts said, “As there is no specific medicine for this epidemic, everyone is required to pay attention to improving immunity.” “Green tea contains a lot of tea polyphenols, catechins, amino acids and vitamins, which can improve immunity and prevent Aging, anti-cancer, sterilization and anti-inflammatory effects."
So, what are the active ingredients in green tea? What are the effects of tea polyphenols and catechins? Can people often drink tea to resist viruses and improve human immunity? On May 4, a reporter from Science and Technology Daily interviewed relevant experts.
The ancients have long recognized the health benefits of tea
China is the hometown of tea. Tea was discovered and used more than 4,700 years ago, and a unique tea-making and tea-drinking culture has gradually formed. There are many kinds of tea preparations in China. The main varieties are green tea, black tea, oolong tea (green tea), white tea, yellow tea, and black tea. Among them, Jiangnan is the main producer of fine green tea.
In the opinion of Dr. Yingchao Li, the leader of the food quality and safety discipline of the School of Inspection, Testing and Certification of Changzhou Engineering Vocational and Technical College, the custom of drinking tea in my country has existed in ancient times, and the ancients have long recognized the health effects of tea. "Drink" said. The "Supplements to Materia Medica" of the Tang Dynasty said: "Tea is the medicine for all diseases".
According to Li Yingchao, modern scientific research results also show that tea contains more than 450 organic compounds and more than 15 inorganic minerals, mainly including basic nutrients, such as vitamins and minerals. The most valuable thing is its rich health activities. Ingredients, such as organic compounds such as catechins, caffeine, flavonoids and tea polysaccharides; these active ingredients have anti-oxidation, anti-cancer, lowering blood lipids, lowering blood pressure, lowering blood sugar, sterilization, anti-inflammatory, and enhancing immunity. Among many types of tea, green tea has higher health value than other varieties.
The researchers pointed out that drinking 5 small cups of tea a day, the intake of theanine is enough to help the body significantly strengthen the resistance to specific bacterial infections, drinking tea beverages for two consecutive weeks can increase the resistance to bacteria.
"Under the high incidence of the global'new crown' epidemic, people are more concerned about the immunity enhancement effect of green tea. However, as far as the current research progress is concerned, tea extracts (mainly tea polyphenols and tea polysaccharides) are immune to the body. Although the enhancement effect of strength has been confirmed, it is still in the stage of animal experiments and no clinical application reports have been seen.” Li Yingchao said, therefore, everyone should be rational about the health benefits of tea, and the physiological regulation effect of food on the body is slow. The process, compared with medicines, is slow but without toxic side effects and requires long-term persistence.
Li Yingchao reminded that, from the current research, there is no doubt that tea has many health benefits, but it should not be overly dependent, let alone listen to rumors, and drink it in moderation. Because, in addition to the above-mentioned beneficial active ingredients in tea, there are inevitably food safety risks such as pesticide residues and mycotoxins during planting and storage, and excessive eating also has health risks.
In fact, after the outbreak of the new crown epidemic in China, the domestic research team reported on the Internet that "tea has good extracellular killing and intracellular proliferation inhibition of the new coronavirus" statement, relevant local governments and scientific researchers also made public. It is stated that although some experiments have been completed, convincing scientific data have not yet been obtained.
Experts pointed out that the in vitro test has an inhibitory effect on the virus and does not mean that the in vivo test will have the same results. It needs to undergo clinical trials to prove its efficacy on the new coronavirus. Therefore, based on the results of this in vitro cell experiment alone, it is not possible to conclude that "drinking tea can prevent new coronavirus infection." Consumers must not trust rumors.
In interviews with reporters, some people in the industry and outsiders generally believe that tea production enterprises should respect science and must not blindly expand the function of tea in their operations, misleading consumption, and causing adverse consequences and impacts in society. Relevant local government departments should pay more attention to guiding the promotion of tea culture, advocating tea ethics and the spirit of tea people, paying attention to scientific research, speeding up technological innovation, and giving better play to the health benefits of tea, improving people's health, and enriching people's dietary life. Promote the healthy development of my country's tea industry.