What Is In Sencha Green Tea?

Sencha tea is the most popular type of green tea in Japan. At the coming of spring, the Japanese look forward to the first picking of sencha, or "shincha," according to the In Pursuit of Tea website. A highly fragrant tea, it contains natural polyphenols, or antioxidant plant chemicals. Green tea extract has a number of promising therapeutic applications.

Production

Camellia sinensis, the tea plant, is the source of green, black, white and oolong teas, which are differentiated only by their processing. The production of sencha begins with tea plants that flourish in moist soil conditions and full sun. The In Pursuit of Tea website explains that gently steaming the leaves to stop oxidation and maintain their deep green color is the first step. The leaves are then partly dehydrated and twisted by a machine, which gives sencha tea leaves their tightly rolled appearance. Sencha does not need to be cured but can be used immediately, and stays fresh for about six months.

Brewing

Imbibing extremely hot sencha or other green teas on a constant basis can injure throat and esophagus tissue, and give rise to an increased risk of throat and esophagus cancer. According to Wayne Kalyn, author of "The Healing Power of Vitamins, Minerals, and Herbs," to optimally prepare sencha tea, heat water to the boiling point and then pour it over the tea leaves. In Pursuit of Tea notes that sencha needs gently handling and brews best with soft water and a brief steeping period.

Health Conditions

In the laboratory, green tea extract has shown potential to act against liver disease, cancer, diabetes and high cholesterol, notes the University of Maryland Medical Center, UMMC. For example, a 2011 issue of "Molecular Nutrition & Food Research" published a study on green tea catechins, or natural plant antioxidants, and cancer treatment. According to the authors, green tea's main catechin, EGCG or epigallocatechin-3-gallate, can hinder the growth of liver and colorectal cancer cells. Green tea catechins, or GTC, demonstrate anticancer properties and inhibit the growth of colorectal adenomas, or precancerous growths. Consult your doctor before using green tea medicinally.

Safety

Speak with your physician before taking green tea supplements or drinking sencha green tea. Sencha green tea is generally safe, but may interact with medications, such as adenosines, beta-lactam antibiotics, beta-blockers, aspirin, blood thinners, chemotherapeutics, ephedrine or lithium, according to the UMMC. Sencha tea contains approximately 40 mg. of caffeine per 8 oz. cup, and pregnant and nursing women should drink a maximum of two cups a day, advises Kalyn.