1.1 What are tea leaves ?
Tea leaves are the leaves and leaf buds picked from tea plant Camellia sinensis (L.) O. Ktze., a species of flowering, fruit-bearing, evergreen shrub or small tree in genus Camellia in the tea family, Theaceae. Originated in southern China, the beverage tea (often made by pouring boiling water onto the dried leaves) is the most consumed drink in the world (not to be confused with herbal teas most of which do not contain tea leaves).
The flowers of the plant are yellow-white, 2.5–4 cm (0.98–1.57 in) in diameter, with 7 to 8 petals. The inedible fruit is multisphere, small in size between 1.1-1.5 cm in diameter with brown to reddish skin, mature fruits will dry in the trees and open to release the seeds. The plant in the wild can grow up to 30 m tall. Native to East Asia, the Indian Subcontinent and Southeast Asia, now extensively cultivated in tropical and subtropical regions (in areas with at least 1,500 mm of annual rainfall), habitats of Camellia sinensis include mountainous regions, forest, wasteland and shrubland (usually found from between 200 to 2,130 meters in elevation). Characteristics of tea plant include tolerance for shade, cold and drought, long lifespan (it may reach 200 years old), ability to withstand cultivation at high altitudes, favorable micronutrient contents.
1.2 What are the major types of tea in the world?
There are four major types of tea in the world that are popular and widely consumed: white tea, green tea, oolong tea and black tea. All of them are made from the same tea plant, i.e. camellia senensis. The differences come from how they are produced to the desired level of oxidation.
White tea is made from young tea leaves or new growth buds, using a fast and minimal processing method leaving the leaves close to the fresh and original tea leaves. Benefits of white tea include reduced risk of cancer, cardiovascular disorder, and improvement in oral health.
Green tea is tea leaves that are quick steamed or pan-fired rather than being exposed to air to reduce oxidation and prevent the breakdown (oxidation) of the catechins. Green tea is therefore lower in caffeine than black and oolong teas.
Oolong (semi-fermented) tea is more processed than green tea, but is not processed for as long as black tea. Oolong tea has unique sweet and fragrant aftertaste.
Black (fermented) tea is made by further processing of leaves, including exposure to heat, light and crushing. It is highly inspiring and energizing because it is enriched with caffeine.
1.3 Are tea leaves edible and how do tea leaves taste?
Yes, tea leaves are edible. But people often boil tea leaves into a concentrated liquid for drinking and do not eat the tea leaves whole because most tea leaves contain a strong bitter taste due to the existence of polyphenolic substances (especially catechins). Though different types of tea base on different tea production procedures tend to have varied tastes, typical teas have a flavor that is refreshing, cooling, mildly bitter, and slightly astringent.
1.4 What is the best time to drink tea?
During the day time, it is suggested that the tea time is between the meals. Taking tea on an empty stomach is bad because the caffeine contained in tea leaves may result in dehydration and also stimulate the release of gastric acid which can cause stomach upset or even ulcer. According to traditional Chinese medicine (CTM), taking tea on an empty stomach will lead to cold accumulation in the lungs and stomach. Also, we should avoid taking tea at meal time due to the fact that it can reduce the absorption of thiamin (vitamin B1).
During the night time, taking tea is not suggested because the caffeine can significantly affect our sleep. A study concluded that consuming caffeine 6 hours before bedtime may reduce the total sleep time by 1 hour. And it is for sure that not getting enough sleep can have profound impacts on a daily and potentially long-term basis for health and mental well-being (harvard.edu 2017).
1.5 How are tea leaves used in traditional Chinese medicine?
Tea leaves are considered sweet, bitter, mildly cold and nontoxic in nature and to be associated with the heart, lung and stomach meridians. It is used as heat-clearing drug, detoxicant, digestion aid, diuretic, astringent, anti-diarrhea drug in traditional Chinese medicine (CTM) and widely adopted in treating different diseases and health problems, such as dysentery and severe diarrhea with mucus or blood in the feces.
2. Uses, Health Benefits of Tea Leaves & Medical Formulas
2.1 Powerful Antioxidants
Though tea plant and tea culture are native to the East, it is becoming more and more popular in the western countries due to its numerous health benefits. One of the most prominent advantages of taking tea is that it contains powerful antioxidants – catechins and flavonoids. Our human body uses antioxidants to protect and heal cells from the free radicals which are produced during normal oxidation activities. Excess and uncontrolled free radicals may cause degenerative diseases associated with aging, Alzheimer’s disease and even different cancers (sheknows.com 2008).
2.2 Reduce Dark Circles Under The Eyes
Many people suffer from dark circles under the eyes. It is for sure that no body want to look decades older than he or she really is. Even children can develop these dark circles under eyes. One main condition that can make the dark circles appear more obvious is swelling under the eyes, commonly called bags. For young people, this swelling may be caused by allergic reactions, illness or an excessive buildup of fluid in the body (mercola.com 2016). External application of tea leaves may help to reduce such swelling as the rich caffeine will shrink blood vessels underneath the skin and therefore reduce darkness around the eye area.
2.3 Heart Health
Heart disease is the leading cause of death in developed countries. One main cause of heart disease is narrowing or blockage of the coronary arteries, the blood vessels that provide blood to the heart. This is called coronary artery disease, and it happens slowly over time. It’s the major situation that people have heart attacks. Different studies have proven that polyphenolic compounds found in green and black tea are associated with beneficial effects in prevention of cardiovascular diseases, particularly of atherosclerosis and coronary heart disease. Also the high provided by coffee tends to last shorter and drop quicker because
2.4 Boost And Maintain Productivity For A Whole Day
While both tea and coffee provide caffeine that are stimulants that keep energetic, studies find out that tea is actually a better choice over coffee. Coffee gives a more powerful stimulating effects than tea, but it can even be so powerful that it may affect the work productivity – the excessive stimulant effect of coffee can make us spend a lot of time on unproductive tasks instead of focusing on working. In comparison, tea has less caffeine than coffee, but it also have other stimulant substances and together provide a more lasting stimulant effect than coffee.
2.5 Better Weight Control
It is a fact that adult obesity rates maintain high in the developed countries. For example, in the US the rate exceeds 35 percent in 4 states, 30 percent in 25 states and are above 20 percent in all states (stateofobesity.org 2016). Tea leaves contain a high level of catechins which can increase fat oxidation (or using body fat as energy) and increase heat production which would result in increased energy expenditure (or calorie burning), meanwhile catechins also decrease appetite which results in reduced food intake (teamworkshealth.ca 2013). A study also found out similar conclusion as exercisers who took of 4-5 cups of green tea and had a 25-minute workout lost 2 more pounds than the non-tea-drinking exercisers.
2.6 Cold, Flu, Fever And Coughing
[CTM Formula] Medicated soju with pork fat, honey, sesame oil and tea leaves is taken orally to treat coughing associated with cold-phlegm syndrome.
[CTM Formula] Alum, fine tea leaves and honey can be processed into pills for oral taking to clear wind related phlegm.
2.7 Reducing Inflammation, Swelling And Relieving Pain
[CTM Formula] A decoction of sichuan lovage rhizome and tea leaves can be taken before meal to heal wind-heat type headache.
2.8 Remove Ulcers
[CTM Formula] Ointment made with powdered rhizomes of picrorhizae, manis pentadactyla (burnt with original property possessed) and tea leaves is to be applied on affected part to treat ulcers.
2.9 The Excretory System
[CTM Formula] Powdered Lygodium japonicum spores and tea leaves is taken with licorice root soup to treat difficulty in passing urine.
[CTM Formula] A decoction of Verbena officinalis and old tea leaves is used in treating dysentery and severe diarrhea with mucus or blood in the feces.
The Ben Cao Medical Book (also known as Compendium of Materia Medica or Ben Cao Gang Mu; Chinese: 本草纲目) is the most famous and comprehensive medical book ever written in the history of traditional Chinese medicine (TCM). Compiled and written by Li Shi-zhen (1518~1593), a medical expert of the Ming Dynasty (1368-1644) over 27 years.
The Ben Cao Medical Book records and describes all the plants, animals, minerals, and other objects that were believed to have medicinal properties in TCM. The book reflects the pharmaceutical achievements and developments of East Asia before the 16th century. On the basis of his predecessors’ achievements in the pharmacological studies, Li contributed further by supplementing and rectifying many past mistakes and misconception in relate to nature of many medicinal substances and causes of various illnesses. Charles Darwin, originator of the biological theory of evolution, regards the book as the “ancient Chinese encyclopedia”.
Disclaimer: The Ben Cao Medical Book is translated by ChinaAbout.net. The information on this website is not intended to replace a one-on-one relationship with a qualified health care professional and is not intended as medical advice. It is intended as a sharing of CTM knowledge and information from the research and experience from the author Li Shi-zhen. Kindly be alert that the CTM knowledge and ancient formulas given above are likely NOT medically proven and may contain misconceptions.
List of reference
harvard.edu 2017 Sleep and Disease Risk [online] Retrieved 21 August 2017. Link: http://healthysleep.med.harvard.edu/healthy/matters/consequences/sleep-and-disease-risk
mercola.com 2016 What Causes Dark Circles Under Eyes? [online] Retrieved 21 August 2017. Link: http://articles.mercola.com/what-causes-dark-circles-under-eyes.aspx
sheknows.com 2008 High-antioxidant teas: Green tea, white tea, red tea and more [online] Retrieved 21 August 2017. Link: http://www.sheknows.com/health-and-wellness/articles/804230/highantioxidant-teas-green-tea-white-tea-red-tea-and-more
stateofobesity.org 2016 Adult Obesity in the United States: The State of Obesity [online] Retrieved 21 August 2017. Link: https://stateofobesity.org/adult-obesity/
teamworkshealth.ca 2013 Green Tea Powder in Weight and Abdominal Fat Loss [online] Retrieved 21 August 2017. Link: http://teamworkshealth.ca/matcha-in-weight-and-abdominal-fat-loss/