For the Chinese, drinking tea for health preservation is a tradition that has been passed down for thousands of years. In recent years, an increasing number of studies have been conducted on the health benefits of tea leaves: anti-cancer, cardiovascular protection, radiation protection... It seems that all potential health risks in people's lives can be resolved with a cup of tea. So, what nutrients are actually in tea leaves? Can drinking tea truly promote health? How should one drink tea to maximize its health benefits?

Cancer prevention is the main effect of tea

Professor Han Chi, a researcher at the Institute of Nutrition and Food Safety of the Chinese Center for Disease Control and Prevention, has been engaged in research on the nutrition and efficacy of tea for decades and is a leading tea expert in China. He told reporters that currently, the more definite health effects of tea include cancer prevention (including lung cancer, esophageal cancer, liver cancer, colon cancer, etc.), regulating blood lipids, lowering blood glucose, enhancing immune function, and preventing damage from smoking. "Drinking tea can repair DNA damaged by smoking, and the effect is very good. This is a conclusion we reached through human experiments, and it can be considered a relatively leading conclusion worldwide."

Han Chi explained, "Now there are many studies on tea around the world, but most are animal experiments using tea extracts. We, however, conducted human experiments using tea soup brewed from tea leaves, proving that people can obtain these benefits as long as they drink tea correctly in daily life."

Jiang Heyuan, an associate researcher at the Tea Research Institute of the Chinese Academy of Agricultural Sciences, who mainly researches tea and health, told reporters that the effective nutrients in tea leaves are diverse, such as the well-known tea polyphenols, as well as theanine, vitamins, caffeine, etc. "According to the production principle, Chinese tea is divided into six categories, namely green tea, black tea, yellow tea, white tea, oolong tea, and dark tea. Later, some reprocessed teas, such as scented tea, were developed based on these six categories." Jiang Heyuan said that different types of tea have different effective components and thus different effects.

Green tea protects the cardiovascular system.

Green tea is an unfermented tea, represented by West Lake Longjing, Dongting Biluochun, and Huangshan Maofeng. Its main effects are preventing cancer and cardiovascular diseases, as well as antioxidant effects, boosting immunity, and inhibiting and killing bacteria.

White tea relieves anxiety

"White tea, according to different classification methods, includes two types," said Han Chi. One is the well-known Anji white tea, which is actually a type of green tea. Due to its smoother taste compared to regular green tea, it has become very popular in recent years. Jiang Heyuan said that the main effects of white tea include protecting brain nerves, enhancing memory, and reducing anxiety. In addition, the theanine in white tea can neutralize some of the effects of caffeine. "People who are afraid that drinking tea will affect their sleep can drink some white tea." The other type is white tea produced in the Fuding area of Fujian Province. "This type of tea has a small yield and a stronger taste than ordinary green tea. According to current research, this tea has good effects on regulating immunity and lowering blood sugar," Han Chi said.

Oolong tea and black tea lower cholesterol

Oolong tea is a semi-fermented tea, represented by Wuyi Rock Tea (Dahongpao), Tieguanyin, Dongding Oolong Tea, and Fenghuang Dancong; while black tea is a fully fermented tea, represented by Keemun from Anhui, Yunnan black tea (Dianhong), and famous black teas from India and Sri Lanka. "Black tea, being fermented, is less irritating than green tea and has different effects, such as promoting blood circulation and lowering cholesterol," Jiang Heyuan told reporters.

Dark tea aids weight loss and reduces fat

Dark tea is a post-fermented tea, with the most familiar being Pu'er tea. It has a high total amount of tea polyphenols and has a good effect on reducing fat and losing weight. According to reports, Professor Benard Jacotot of the Henri Mondor Hospital in Paris gave 20 patients with high blood lipids three bowls of Yunnan Pu'er tea a day. After one month, the patients' blood lipids were reduced by almost a quarter. Japan's "Health" magazine introduced that Pu'er tea can inhibit weight gain and reduce cholesterol and triglycerides in the blood. "Some famous teas, such as Mingqian tea from Longjing, have the same types of effective components as ordinary tea, but the content may vary," Jiang Heyuan explained. Mingqian tea, because it is picked early, has higher content of theanine and Vitamin C, but lower content of tea polyphenols. "For health preservation purposes, there is no need to buy particularly expensive tea," Han Chi reminded. So which type of tea is the most nutritious? The two experts believe that in terms of the total amount of polyphenols, each type of tea is roughly the same. However, because the processing technology for green tea is the simplest, its nutrient components are better preserved.

How to drink tea most healthily? After choosing tea that suits you, how to make it exert its maximum effect is also a science. Han Chi said: "Different teas have different methods of storage, brewing, and drinking."

Storage: Tea is most afraid of moisture and odors

The best containers for storage are tin cans, porcelain jars, and colored glass bottles; followed by iron containers, wooden boxes, bamboo boxes, etc.; plastic bags and paper boxes are the worst. The container should be dry, clean, and free of any odor. The properly stored tea should be kept in a dry and ventilated place, away from moisture, high temperature, unclean environment, and direct sunlight. These places should not have items with strong odors such as camphor, medicines, cosmetics, cigarettes, and cleaning products. New green tea from the current year can also be sealed and stored in the freezer compartment of a refrigerator, where it can be kept for 3-6 months.

Brewing: Rinsing tea should be no more than 15 seconds

"Nowadays, people like to rinse tea before drinking, but I don't agree with excessive rinsing," Han Chi said. In our experiments, we found that the extraction rate of effective components after rinsing green tea twice was over 70%, and for black tea, over 60%. That is, if you rinse tea excessively, a large amount of nutrients will be lost. Jiang Heyuan reminded that if tea must be rinsed, the rinsing time should not exceed 15 seconds. Green tea and white tea should preferably not be rinsed. "But there is an exception: people who are sensitive to caffeine can rinse the tea once before drinking, because caffeine leaches out faster than tea polyphenols, and a quick rinse can remove some of the caffeine."

Consumption: 12 grams per day is most suitable

Jiang Heyuan suggests that for ordinary people, drinking about 12 grams of tea per day, divided into 3-4 infusions, is appropriate. People who consume a lot of greasy food, smoke, or drink heavily can appropriately increase the amount of tea. Pregnant women, children, people with neurasthenia, and those with tachycardia should appropriately reduce the amount of tea they drink. Han Chi reminded that with the popularity of Gongfu tea, people are drinking tea "hotter and hotter," which is very wrong. "People drink tea for health preservation, but drinking hot tea increases the incidence of cancers such as esophageal cancer, which is not worth the gain. The optimal temperature for drinking tea should be around 60 degrees Celsius, not exceeding 70 degrees."

In addition, different teas can be drunk at different times of the day: drink a light cup of green tea in the early morning to refresh the mind; drink jasmine tea in the morning for its fragrance and to improve work efficiency; drink a cup of black tea in the afternoon to relieve drowsiness and refresh; in the evening, when gathering with family or friends, brewing a pot of oolong or Pu'er tea adds a special charm without affecting sleep. This daily tea drinking arrangement can be tried.

Leftover tea can also be put to good use

It is no exaggeration to say that tea is entirely a treasure. As long as it is properly utilized, "outdated" tea leaves can still play a role.

One: Overnight tea.

Jiang Heyuan said that drinking overnight tea is actually not harmful, but tea is easily oxidized, so the teacup for overnight tea often has tea stains. In addition, the temperature is high in summer, and tea is easily contaminated by bacteria, becoming moldy and smelly, leading to diarrhea. Therefore, it is better not to drink overnight tea in summer. If you are reluctant to throw it away, it can be used for the following purposes: 1. Overnight tea is rich in acids and fluorides, which can not only prevent capillary bleeding but also play a bactericidal and anti-inflammatory role. For example, bleeding in the mouth or on the skin can be washed and rinsed with it; 2. Using overnight tea to wash your hair can treat scalp itching; 3. Bad breath troubles many people. If you rinse your mouth with overnight tea three times a day, you can eliminate the trouble of bad breath.

Two: Old tea and tea dregs.

For green teas like Longjing, people prefer to drink the new tea of the current year. If some is left over, these tea leaves can still be used effectively: 1. Making dishes. When stewing meat or cooking other greasy, fishy dishes, a bit of tea can be added to remove grease and reduce greasiness; 2. Tea dregs can be dried and stored, and together with old tea, made into tea pillows, which are especially suitable for summer use. If there isn't enough tea, it can also be made into small tea bags for applying to the eyes to relieve visual fatigue; 3. Spread the brewed tea leaves after drying in damp places in the house, such as under the bed, to absorb moisture.