US media: new research shows that drinking green tea instead of black tea may contribute to longevity

Chinese researchers have found that people who drink green tea rather than black tea may live longer, especially for men, US media said A new study shows that drinking tea at least three times a week can reduce the risk of death from cardiovascular disease, and that drinking tea is related to longevity and health, at least in China The researchers studied the data of 100902 Chinese people who had no history of heart disease, stroke or cancer and divided them into two groups: those who drank tea habitually (i.e people who drank tea more than three times a week) and those who never or did not drink tea habitually (i.e people who drank tea less than three times a week) They followed up the respondents for seven years Their analysis found that regular tea drinkers had a 20 percent lower risk of heart disease and stroke and a 22 percent lower risk of dying from heart disease and stroke Compared with those who don't drink tea very often, those who often drink tea may live 1.26 years longer at the age of 50 "We found that for men, the protective effect of tea drinking habits is very obvious, but for women in general," Gu Dongfeng, Ph.D., from the National Cardiovascular Center, Peking Union Medical College Hospital and the Chinese Academy of Medical Sciences, said in an email "One reason may be that the proportion of men who have the habit of drinking tea is about 2.5 times that of women," Gu said About 48% of men in the survey regularly drink tea, compared with 20% of women Chinese women are more likely to drink rose tea or lotus leaf tea, but that information is not included, Gu said In their analysis, the researchers controlled factors such as smoking, drinking, diet and physical activity to explain the relationship between tea drinking and longevity However, as an observational study, it can not determine causality, only the relationship Jody Ralph, a spokesman for the British dietician Association and registered dietician, said: "other questions not mentioned in the report include: first, what did those who did not drink tea drink - was tea replaced by sugary or caffeinated drinks, and did this increase the risk?" Professor Gu said the benefits of drinking black tea were "not statistically significant," but this could be because there were far fewer black tea drinkers in the study - only about 8% said they liked black tea Professor Gu also said that green tea is rich in flavonoids, especially tea polyphenols, which can prevent cardiovascular disease Although black tea comes from the same plant, the processing method of black tea after picking is different from that of green tea "Black tea is fully fermented, and polyphenols can be oxidized into pigments and inactivated during fermentation," he said Therefore, green tea is often more effective than black tea in antioxidation, so as to improve blood lipid status and protect cardiovascular system more effectively " As the most popular drink in the world, Gu said that tea drinking habits vary from place to place, and this research result may not be applicable to western countries In the west, black tea is a more popular choice - usually with milk or sugar Duane mailer, a registered nutritionist and senior assistant professor at Aston medical school at Aston University, said that although green tea is safe and may also have benefits, green tea health products "should be cautious, because there are a large number of cases of liver injury reported, and these people have taken a large number of green tea health products."