Drinking Green Tea Hurts the Liver?
Drinking green tea hurts the liver? European Food Safety Authority issues health warnings:
Daily intake of catechins exceeding 800 mg or liver damage
Health Times reporter Chu Chao
Recently, the European Food Safety Authority released the “Safety Evaluation of Green Tea Catechin” report, which issued a health warning to the public: 800 mg or more of catechins per day (to be precise, EGCG, epigallocatechin Gallate), may cause elevated aminotransferases and damage the liver.
It is understood that green tea catechins are currently widely used in various parts of the world, and their products involve beverages, foods, health products and other fields. Especially in European and American countries, catechins are the main ingredients of common dietary supplements.
So, does this mean “drinking green tea hurts the liver”? The report states that it is not likely that excessive intake of catechins will be caused by drinking green tea daily, but those who eat green tea extracts or diet pills should look at the ingredient list carefully.
Liver injury has a great relationship with weight loss products containing green tea ingredients
Catechin is a general term for flavanols in tea. It is the most important type of tea polyphenols, accounting for 75% to 80% of the content of tea polyphenols. Due to the difference in the production process, the catechin content in unfermented green tea is the highest among the six major teas.
EGCG is the highest content of catechins, and it is also the main component of tea polyphenols’ biological activity. Many studies have been conducted with EGCG intake instead of catechins.
Regarding the hepatotoxicity of green tea extract, it mainly came from some weight loss products. For example, in 2003, a weight loss product containing green tea was withdrawn from the market because 13 liver injury cases were reported after marketing, and the incidence rate was 1 liver injury per 100,000 boxes of products sold. Since then, more weight loss products containing green tea have been recalled due to suspected hepatotoxicity, and research on the relationship between green tea and liver damage has begun to receive more and more attention.
Victims are mostly adolescents and middle-aged women
In 2012, a 17-year-old named Christopher was admitted to the emergency room of the Texas Children’s Hospital in the United States. According to his attending doctor, the patient’s chest, cheeks, and eyes looked “bright yellow like a highlighter.” The reason was that he had previously purchased a “burn fat” supplement (a concentrated green tea extract) from a nutritional supplement store, and suffered severe liver damage after taking it. Because the area of necrosis is too large, he needs a liver transplant
Christopher’s case is not isolated. An analysis conducted by the National Network of U.S. Liver Experts showed that liver damage caused by taking dietary supplements including green tea supplements accounted for about 20% of all drug-related liver damage in the hospital. Although many patients recovered after stopping taking supplements and receiving treatment, a few patients needed a liver transplant or died from liver failure.
Researchers said that young people with insufficient life experience are not the only high-risk consumer groups, and many middle-aged and elderly women who believe that green tea extracts can promote “fast weight loss” or “anti-cancer and anti-cancer” are especially popular.
A 2017 cancer prevention study found that after menopause women took green tea extract twice daily as a breast cancer medicine trial for one year, their liver enzymes rose, which is a potential sign of liver damage and is common in alcoholics . This amount of green tea intake has reached the borderline of liver injury, so everyone should be careful with green tea extract supplements.
EGCG daily intake of more than 800 mg may cause elevated aminotransferases
The European Food Safety Authority found 38 population intervention studies that investigated the relationship between EGCG and transaminase through a search, and a review article in 2016, and comprehensively analyzed them and concluded:
As of now, there is no evidence that daily EGCG intake below 800 mg can cause liver damage, but if this amount is exceeded, it may cause elevated aminotransferases.
It should be noted that 800 mg here is not necessarily the true threshold for EGCG liver toxicity, in other words, less than 800 mg daily intake may also cause liver damage. However, there is a lack of research in this area, and a rigorous dose-response relationship study is needed.
Just drink it, it’s safe to brew green tea
There are three main intakes of green tea catechins: brewed green tea, green tea beverages containing green tea extracts, and dietary supplements. How about their respective security? We first need to convert how much tea or tea soup is 800 mg EGCG.
According to the European Food Safety Agency estimates, 100 grams (dry weight) of green tea contains about 7,000 mg of EGCG, and 100 grams of green tea tea soup contains about 70 mg of EGCG, which refers to the average value of EGCG in different varieties of green tea.
After conversion, to consume 800 mg of EGCG, you need to chew 11 grams of dry green tea leaves daily, or drink 1100 grams of green tea head tea soup.
According to the analysis of “Status of China’s Tea Industry-Tea Domestic Sales Data”, the per capita consumption of tea in China in 2015 was about 1,300 grams, that is, the average daily tea consumption was about 3.6 grams. The study also found that among tea drinkers in China every week, the average daily consumption of tea by men was 4.5 grams, and that by women was 3.0 grams, which are far lower than the 800 milligrams of EGCG.
It can be seen that it is safe to brew green tea daily.
Drinking green tea in moderation does not hurt the liver, but be wary of high sugar and additives
What about green tea drinks? According to the “Research on the Content of Tea Polyphenols in Commercially Available Tea Beverages”, the two most popular green tea beverages on the market have tea polyphenol contents of 1121 mg and 930 mg per kilogram respectively, which are converted into EGCG amounts of approximately 680 mg and 523 mg. Moreover, after the green tea drink is opened, some tea polyphenols will be oxidized, and the EGCG content will be further reduced. Therefore, even if you drink 1 kg (about 1 liter) of green tea a day, the intake of EGCG is still below 800 mg, which is relatively safe.
However, drinking green tea drinks should pay attention to the health problems of high sugar and excessive additives, especially young people.
The European Food Safety Authority also stated that, based on the assumptions of the safety method, the catechin content of green tea soup and green tea beverages brewed in the traditional way is generally considered safe.
The most important thing to pay attention to is the “green tea essence” category of health products
Dietary supplements such as green tea catechins are very common in European and American countries. Some health care product brands have gradually entered the market, and they have been blown up.
The reporter searched on the shopping site with keywords such as “catechin”, “tea polyphenols” and “EGCG” and found that these health products are mainly divided into two categories: one is imported “green tea essence capsules” and the other is produced by domestic manufacturers “Green tea polyphenol powder”, and most of these two types of health products are under the banner of “anti-cancer, anti-bacterial, anti-virus,” “clearing lungs and removing smoke,” and “fat-reducing”.
Based on the report of the European Food Safety Agency, consumers need to pay attention: if you are taking health products containing green tea extracts such as “EGCG catechins”, then you must read the instructions carefully to calculate the amount of EGCG you consume in a day. If there are other intake routes, such as drinking green tea, then pay attention to whether EGCG intake is exceeded.