Tea has been considered the healthiest drinks, which has been described in various historical documents. For example, “Shen Nong tasted hundreds of herbs, gotten poisoned by seventy-two poisons, and is detoxicated by tea.” indicates that tea can be used as a medicine to detoxify. In the Tang Dynasty book “Herbal Supplements”, it mentions that “regular medicine can be used to cure a specific diseases, but tea can be used to cure thousands of diseases”, which proofs that there are many health benefits associated with tea. In the pass, the cognition of the health benefits of tea is due to the accumulation of experience, but now that knowledge is also proofed by modern scientific research. Base on the researches conducted by domestic and foreign institutions, the health benefits of tea are described below.
Slowing Down Aging:
To prevent the chain damaging effects of free radicals in the body, usually there is an enzyme system designed to scavenge those free radicals and maintain a dynamic balance. But along with aging (after 35 years old), the enzyme system will gradually decline, which increase the amount of free radicals and accelerates aging.
In green tea, oolong tea and black tea, scientists have found catechins and oxides components, which have strong antioxidant effects. They can neutralize free radicals generated from different part of human body and thus, delay aging, prevent lipid oxidation and ameliorate allergies.
Lowering Blood Lipids and Preventing High Blood Pressure:
Tea has effects that can improve lipid condition, especially with lowering LDL and raising HDL. Japanese scholars have conducted a research on 33 healthy participants by giving each of them 500 mg of catechins per day (about 10 cups of tea). After 3 months, the effected was measured by the change in their lipid content: although the total cholesterol levels did not change, the high-density lipoprotein cholesterol concentrations increased significantly.
Hypertension is a common disease among the elderly, and one of the main causes is the high level of sodium in the blood. Tea is rich in “K” ions, which can promote the exclusion of blood “sodium” ions and thereby prevent hypertension. Experiments have proof that for a healthy person, a daily intake of 500 milligrams of catechins can significantly decrease the diastolic and systolic blood pressure in 3 months. As a result, casual tea drinking can prevent hdigh blood pressure in long-term.
Lowering Blood Sugar and Preventing diabetes:
Some of the components in tea have been shown to have a hypoglycemic effect, especially the water-soluble polysaccharide compound heterochain extracted from tea. After clinical trials on more than a hundred diabetic patients, tea has been proved to have the effect of lowering blood sugar level.
Prevention of Dental Caries:
The anti-caries effect is caused by the Fluoro in tea. Fluorine can replace tooth hydroxyapatite hydroxyl and convert it into Fluor apatite, enhance the resistance of enamel to acid erosion. Furthermore, catechins can also inhibit the cariogenic bacteria, which has been proven from clinical trails.
Catechins can significantly reduce plaque and periodontal disease index, but leave other microbes in the mouth unaffected. Therefore the catechins and fluorine in tea together can prevent dental caries.
Antibacterial and Antiviral:
The antibacterial and antiviral functions of tea have been recorded in Chinese medicine books in early Tang and Song Dynasty. Tea has long been used to treat inflammation. Modern science believes that catechins in tea can suppress and sterilize many human pathogenic bacteria such as Staphylococcus aureus, Vibrio cholerae, Escherichia coli and Clostridium botulinum; at the same time, it is not harmful to intestinal bacterial such as lactic acid bacteria and beneficial for digesting system.
China and Soviet Union had used tea to treat dysentery and inhibit pathogenic bacteria in clinical trails. Japanese clinical trials use catechins extract from tea to treat genital warts and achieved successful result. Catechins extracted from black tea can prevent influenza.
Preventing Anti-cancer Cell Mutations:
In Japan, researchers have conducted a survey in Shizuoka County region, where stomach cancer mortality rate is much lower than average. One possible answer is that this place is famous for tea and the residents drinks more tea than people from other places.
Catechins intake below 50 ~ 100 ppm, can prevent Pvroli bacteria (bacteria that cause stomach cancer). During an experiment, 34 Pvroli carrier were given 700 mg of pure catechin. After a month, almost all of them had reduced the number of bacteria and six of them even fully recovered. As a result, catechins may inhibit the action of gastric cancer.
Protecting from Radiation and UV:
A research conducted on people who were exposed to radiation in Hiroshima during World War II shows that those who keep drinking tea afterwards have longer life expectancy and health conditions are better.During the same period, scientists in France and Soviet Union during confirmed that tea catechins has protective effect for irradiated mice and proved that the catechins has the feature of radiation protection. In China, during radiation therapy, sometimes tea is used as leukocyte to increase agent during therapy.
Based on animal studies, researchers found that catechins can reduce skin cancer caused by the UV-B. According to this principle, a US company developed a cosmetic cream based on green tea processing system. The labeled function of this product is to protect from UV radiation, prevent skin cancer and early skin aging.
Help Strengthen the Bone:
From 1996, a hospital affiliate with a successful university has been conducting a survey on 497 men and 540 women. The biennial review showed that the more tea people drink, the higher bone density they have. In other words, participants who have been drinking tea for more than 10 years has the highest bone density; participants who have been drinking tea from 6 to 10 years have 2.3% higher bone density than non-tea drinkers. Over ninety percent of participants drink oolong tea and green tea. The result is contradictory to the conventional theory that tea can cause osteoporosis.
Thanks to technological progress, a number of researchers have suggested that in addition to promoting tea culture, people should also consider using new technology to extract catechins from tea in order to improve public health. Therefore, in the market there are health food products that are extracted from tea, some of them only contain catechins, some others have added multiple antioxidants extracts from other plant as well. While using those products with high catechins concentration, please pay attention to whether caffeine has been removed. If it is not, please make sure the dose is low because high caffeine can cause discomfort.
When medication, especially drugs containing iron, people should avoid drinking tea at the same time because tea catechins may react with some component in the drugs and make the drugs lose effect. If you want to drink tea, you should wait 1.5-2 hours after taking the medicine. This is something tea drinkers should keep in mind.
“Drink more tea can be beneficial for both physical and mental health.”–this is a slogan that can be hear very often when people promote tea drinking. But we must be aware of that tea is only a health food that can adjust our body system, instead of medicine. So we cannot use tea to treat diseases. However, in terms of preventing disease and enhance immunity, there is no doubt that tea is good for our health.
Content Resource: “Scientific Development” in July 2005, 391 edition, page 66-73