Can milk and tea be drunk together?

　　After modern scientific investigation, people who drink a lot of tea have cardiovascular disease disease wait slowly sexually transmitted diseases The incidence rate is lower. Scientists speculate that polyphenolic compounds in tea play a role. The polyphenolic compounds in tea, often called "tea polyphenols", have antioxidant functions and can reduce oxidative damage to cells. However, the proteins in milk may be bound to polyphenolic compounds. Whether this combination will affect the efficacy of drinking tea has attracted people's attention. Although the history of adding milk to tea is quite long, perhaps because there are not that many Europeans who believe that "what their ancestors passed down must be correct", this issue has triggered many scientific studies. Testing this question in a test tube is not difficult. Scientifically, there are many ways to test the antioxidant activity of a substance. Scientists used these methods to test brewed tea - and sure enough, the tea had pretty good antioxidant activity. If you add the amount of milk that British people usually add to tea, the result is that the antioxidant activity is greatly reduced!

　　This seems to indicate that milk can indeed inhibit the "health function" of tea. However, this suppression is caused by the combination of milk and polyphenols. After drinking it into the stomach, the protein will be broken down and digested, and the polyphenols may be released. Can these polyphenols be absorbed? Is it still active? This is the more important question.

　　So scientists need to design other experiments to answer such questions. They found some volunteers, and after starving them for a night, they first drew their blood, then gave them a cup of tea, and then drew blood again every few dozen minutes. On the one hand, these blood levels of polyphenolic compounds can be analyzed directly. Tea polyphenols is a general term for a variety of substances, and the most important types can be analyzed. This method is very intuitive, but it can only analyze known polyphenol types, and inevitably misses some unknown ones. On the other hand, antioxidant activity in blood can be measured directly. Then find another day and do it again, but this time drink tea with milk.

　　The volunteers contributed many blood samples, and the scientists were able to draw a curve describing changes in the levels of polyphenolic compounds, or antioxidant activity, in the blood over time before and after drinking the tea. The results show that after drinking tea, the polyphenols and antioxidant activity in the blood gradually increase. Different teas will reach a maximum value at different times, and then gradually decrease until they return to the levels before drinking tea. In other words, it is a reliable method to detect whether tea polyphenols have reached the blood by analyzing the blood.

　　Italian scientists published a study, and their results showed that when milk was added to tea, the antioxidant activity in the body was completely inhibited. This result is consistent with the results of test tube experiments conducted by other scientists. However, their own test tube experiments showed that milk had no effect.

　　This result is somewhat unexpected, and other scientists have conducted other experiments. In the May 1998 issue of the same magazine, Dutch scientists published a similar experiment. They directly measure the levels of catechins - the most important tea polyphenols - in the blood. The result is: adding milk to tea has no effect on the absorption of catechins.

　　These two results are quite conflicting. However, in healthy field, such situations are not uncommon. If we selectively accept the conclusions we "expect", support can be found for both positive and negative conclusions. “Will milk affect the absorption of tea polyphenols? This question requires more experiments by other scientists to verify. In the following 10 years, scientists from the Netherlands, India, and the United Kingdom published other experiments, and the results were that milk did not affect the absorption of polyphenols in tea.

　　In this way, the issue seems to have been settled. However, this actually just proves that we can get the same amount of tea polyphenols regardless of whether milk is added to the tea. It is still unclear whether these tea polyphenols really play a "health care role" in the body. Although epidemiological surveys show that people who drink more tea have lower rates of chronic diseases such as cardiovascular disease, it is entirely possible that this is caused by other lifestyles of these people - for example, they tend to eat healthier, etc. To explain the "health benefits" of drinking tea, more scientific data is still needed.

　　Because the polyphenol compounds in green tea are much higher than those in black tea, it is generally believed that green tea has better "health benefits". The U.S. Food and Drug Administration (FDA) once carefully analyzed 223 papers on "green tea anti-cancer" and believed that only a few studies could explain the problem, but the results were inconsistent - some showed no effect, and some showed a weak effect. ； And studies that showed usefulness were not subsequently replicated by other researchers. As a result, the FDA concluded that green tea is "highly unlikely" to have anti-cancer effects.

　　In fact, it is not that important whether tea polyphenols can be absorbed and whether they can play a health-care role after absorption. Regardless, tea is still a great drink. It contains no sugar, no salt, and almost no calories. The best thing is that it allows us to drink water happily to quench our thirst. Its "health care effect" may be used as a source of conversation over tea, but there is no need to take it too seriously.