The benefits of drinking tea
Tea can invigorate people's spirits, enhance their thinking and improve their memory. Tea polyphenols help the brain to localize, improve memory and improve learning efficiency. Foreign studies have confirmed that drinking tea can prevent and treat nervous system diseases, especially elderly cognitive disorders. In addition, caffeine can stimulate the central nervous system, and has the effect of refreshing, benefiting, and clearing the heart.
Excerpted from the book "Chinese Tea Culture" edited by Ding Yishou, Zhang Chuanzheng, belonging to the cultural common sense series of [Chinese sturgeon•Classic Reading Action]
The discovery and use of tea, the legend began in the Shennong era more than 4,700 years ago, people discovered that fresh tea function of detoxification ("Shen Nong Ben Cao Jing" is recorded in the book). The famous Chinese doctor Hua Tuo of the Eastern Han Dynasty proved that drinking tea can refresh body and benefit the health. According to the scientific determination, there are more than 700 compounds that have been isolated and identified in tea.
Tea composition and health functions:
1. Inorganic component
The inorganic component accounts for 3.5%-7.0% of the total dry weight of the tea. There are nearly 30 kinds of inorganic elements found in tea. Phosphorus and potassium are the most abundant, followed by calcium, magnesium, iron, manganese, aluminum, and sulfur. The trace elements are zinc, copper, fluorine, molybdenum, selenium, and boron. Lead, chromium, nickel, cadmium, etc.
Potassium can regulate the balance of body fluids. In summer, people must add potassium after sweating. Drinking tea is an effective way to supplement potassium.
Zinc is an essential element for human growth. Zinc deficiency can cause growth and development, and tea can supplement a part of zinc.
Fluoride is an essential element of the human body, and lack of fluoride can cause osteoporosis and tooth decay. However, excessively old tea leaves contain more than 30 mg/kg of fluoride. Frequent drinking of this high-fluorine tea can cause excessive fluoride and poisoning, and dental fluorosis and bone variability.
Selenium is an essential element of the human body and has many health effects. It can enhance immune function, anti-oxidation, eliminate excess free radicals, fight cancer, and resist mutation.
Calcium and iron are also essential elements of the human body. Drinking tea can supplement a certain amount of calcium and iron, which is beneficial to health.
2. Organic ingredients
Organic components account for 93%-96.5% of the total dry weight of tea
(1) Tea polyphenols
Tea polyphenols are a general term for polyphenols in tea, including catechins, anthocyanins, flavonoids and phenolic acids. Important among these are catechin compounds, which account for more than 70% of the total polyphenols.
Tea fresh leaves contain 20%-35% tea polyphenols. After making different teas, the amount of tea polyphenols is not the same , green tea has the most, followed by white tea, yellow tea, oolong tea and black tea again. After the reduction of tea polyphenols, oxidized polymers such as theaflavins, camellitin, and tea brown pigment are mainly formed.
The main health functions of tea polyphenols include antibacterial, anti-oxidation, anti-oxidation, inhibition of arteriosclerosis, blood pressure lowering, blood sugar lowering, anti-radiation, anti-cancer, anti-HIV, anti-allergy, detoxification and deodorization of heavy metals.
(2) Proteins and amino acids
The protein content in tea accounts for more than 20% of the total dry weight of tea, but only accounts for about 2% of water. This part of the water-soluble protein is one of the ingredients that form the taste of tea soup. The amino acid is the basic substance that constitutes protein, and its content accounts for 1%-4% of the total dry weight of tea, and spring tea is higher than in summer and autumn tea. Fine tea is higher than coarse old tea, and the content of bud and the tender stem is higher than the mature leaf. , higher than the old leaves.
The functions of amino acids include: improving brain nerve communication ability, protecting sperm cells, calming, improving memory, losing weight, protecting liver, anti-oxidation, enhancing the efficacy of anticancer drugs, and enhancing immune function.
The sugars in tea include monosaccharides, disaccharides, and polysaccharides. Most of them are water-insoluble polysaccharide compounds, such as starch, cellulose, hemicellulose, lignin, etc., accounting for more than 20% of the total dry matter. The more the tea leaves, the lower the polysaccharide content.
The bioactive complex polysaccharide in tea is a kind of acidic polysaccharide or acid glycoprotein which is combined with protein.
The main effects of tea polysaccharides are: lowering blood sugar, lowering blood fat, and resisting radiation.
The alkaloids in tea include caffeine, theobromine, and theophylline. Among them, the content of caffeine is the highest, accounting for 2%-5% of the dry weight of tea, and the other two alkaloids are rare. Caffeine is easily soluble in water and is an important ingredient in the formation of tea soup. Drinking tea can refresh and diuretic is the role of caffeine. The content of caffeine, summer tea is higher than spring tea, and young leaves are higher than old leaves.
The positive effects of caffeine include the impact on excitement, heart, diuresis, promotion of digestive juice secretion, weight loss, etc.
(5) Tea pigment
The pigment in the tea includes two parts, a fat-soluble pigment, and a water-soluble pigment, and the content is only about 1% of the dry weight of the tea. A water-soluble tea pigment that is effective against the human body. Here, "tea pigment" refers to a tea polyphenol oxidation high polymer and a cracking product thereof which are extracted and extracted from black tea. Oxidation of tea polyphenols forms high-oxidation polymers such as theaflavins, camellitin, and tea brown pigment. The content of these oxidized polymers is highest in black tea, followed by oolong tea, and yellow tea and white tea again. There is only a very small amount of oxidized polymer of tea polyphenols.
A large number of clinical trials have shown that "tea pigment" has a certain effect on the prevention and treatment of cardiovascular diseases, can lower blood lipids and cholesterol, and prevent atherosclerosis.
Tea is rich in vitamins, which account for 0.6% to 1% of the total dry weight of the tea. Water-soluble vitamins C, B, fat-soluble vitamins A, D, K, etc., so drinking tea is an excellent source of vitamins needed to supplement the body. Among them, vitamin C content is the highest, and the content of 100 grams of high-grade green tea can reach 250 mg. In general, green tea has a higher vitamin content, and less is contained in oolong tea and black tea.
Vitamin C has the antioxidant capacity, can enhance the body's immune function, prevent colds, promote iron absorption, anti-cancer, anti-aging, and prevent scurvy.
In addition to vitamin C, tea also contains vitamin A, vitamin B, vitamin E, K, F and so on.
Vitamin A can maintain the normal function of vision and hearing, maintain the health of skin and mucous membranes, and promote growth.
Vitamin B1 promotes growth and maintains normal activities of nerve tissue, muscles, and heart.
Vitamin B3 can participate in the metabolism of nucleotides and amino acids, promote cell proliferation, and prevent anemia.
Vitamin E has an antioxidant effect, which can delay aging, prevent infertility, and prevent arteriosclerosis.
Vitamin F (linoleic acid, linoleic acid, etc.) has an effect of preventing arteriosclerosis and maintaining skin and hair health.
Vitamin K can promote the synthesis of prothrombin, prevent and treat bleeding, and promote the absorption and deposition of calcium in bone.
Both tea and tea seeds contain saponin compounds, which have the functions of improving immune function, antibacterial, anti-oxidation, anti-inflammatory, anti-viral and anti-allergic effects.
(8) Aromatic substances
The aromatic substance in tea refers to the general name of volatile substances in tea, and the content is only 0.005%-0.03% of the dry weight of the tea. The aroma of the tea is the combination of different aromatic substances at different concentrations and the combination of olfactory nerves. Although there are not many aromatic substances in tea, the types are very complicated, and they belong to more than ten kinds of alcohols, phenols, aldehydes, ketones, esters, lactones, nitrogen-containing compounds, sulfur compounds, hydrocarbons, and oxides. There are about 700 kinds of tea aromatic substances that have been isolated and identified so far, but only a few of them are mainly composed. Some of them are synthesized during the growth of fresh leaves, while others are converted during the processing of tea. In general, fresh tea leaves contain less than 80 kinds of aromatic substances, while there are more than 260 kinds of green tea and more than 400 kinds of black tea. The combination of different types and different amounts of various compounds constitutes a variety of unique tea aromas.
There are many kinds of aromatic substances in tea, and the content of each aroma substance is extremely small. Many aroma substances have many functions such as calming, analgesic, sleeping, relaxing (reducing blood pressure), antibacterial, anti-inflammatory, deodorizing and so on.
In the Tang Dynasty, "The Supplement to Herbal Medicine" the discussion about tea has mentioned that "long-term food is thin," modern scientific research confirms this. The caffeine in tea can promote the secretion of gastric juice, help digestion, and enhance the body's ability to break down fat. Foreign studies have also shown that regular tea drinking can reduce waist circumference and lower body mass index (BMI), which can help prevent diabetes and cardiovascular and cerebrovascular diseases.
In summary, tea contains a variety of inorganic substances and organic substances, which have both nutritional value and obvious physiological regulation functions and health effects. Therefore, drinking tea cannot only quench your thirst but also promote health.
About the Author:
Ding Yishou, Executive Deputy Director of the Institute of Chinese Culture, Anhui Agricultural University, Master Instructor, Deputy Secretary General of Anhui Tea Society, Secretary General of Anhui Huicha Culture Research Association, Member of Academic Committee of China International Tea Culture Research Association. He has been engaged in the teaching and research of tea culture for a long time. He is the editor or co-author of "Chinese Tea Culture", "Chinese Tea Ceremony", "Chinese Tea Art", "Huang Shan Mao Feng", etc., compiling or co-authoring "Tea Culture" and "Chinese Tea History", ", "Chinese tea spectrum", "tea table, tea party" and other textbooks and books, published more than 40 papers.
Zhang Chuanzheng, Doctor of Tea Science, Postdoctoral Fellow, Director and Associate Professor of Tea History Research Office of China Tea Culture Research Institute of Anhui Agricultural University, Director of Anhui Huicha Culture Research Association, Member of Expert Committee of China Tea Circulation Association. He presided over the "Anhui Tea Science and Technology Development History and Academic Evaluation" of the Anhui Provincial Department of Education, the Provincial Postdoctoral Science Fund, "Human Business Model and Performance Research of Huizhou Merchants", and the "Easy Homemade Health Tea", and participated in the "Chinese Tea Ceremony". 5 textbooks and books such as "Chinese Tea History" and "World Tea Culture".