Tea is one of the most common drinks in all over the world. Rapid urbanization and industrialization in recent decades has increased heavy metals in tea and other foods. In this research, heavy metal contents such as lead (Pb), cadmium (Cd) and arsenic (As) were determined in 105 black tea samples cultivated in Guilan and Mazandaran Provinces in north of Iran and their tea infusions. The amount...

Description and Constituents Tea is one of the most widely consumed beverages in the world today, second only to water, and its medicinal properties have been widely explored. The tea plant, Camellia sinensis, is a member of the Theaceae family, and black, oolong, and green tea are produced from its leaves. It is an evergreen shrub or tree and can grow to heights of 30 feet, but is usually prun...

BACKGROUND Recently, the anticarcinogenic effects of green tea have been studied in sites other than the urinary tract. The present study examined the inhibition by green tea of vesical tumors induced in rats by N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN). METHODS In the first series of experiments, 0.05% BBN was added to the drinking water of rats and remained present for 5 weeks. In one ex...

Tea is believed to be beneficial for health, and the effects of the fermentation process on its contributions to apoptosis and cell cycle arrest of gastric cancer cells have not been completely investigated. In this study, the chemical components in green tea, black tea and pu-erh tea aqueous extracts were analyzed and compared. The polysaccharide and caffeine levels were substantially higher i...

Consumption of tea has been shown to improve endothelial function. It is assumed that catechins are the tea components responsible for these beneficial effects. In black tea, catechin concentrations are significantly lower than in green tea. The present study was designed to compare green and black tea with regard to amelioration of endothelial function. Endothelial function in response to both...

There is substantial in vitro and in vivo evidence implicating tea polyphenols as chemopreventive agents against various cancers. In a case-control study conducted among Asian-American women in Los Angeles County, we reported a significant inverse relationship between intake of green tea and risk of breast cancer (A. H. Wu et al., Int. J. Cancer, 106: 574-579, 2003). Because catechol-containing...

Background: Green tea is a popular type of tea that is made of unfermented tea leaves. Green tea has been used for thousands of years by people in Eastern countries for a variety of health reasons. One of the primary benefits of Green Tea in regard to fertility is not in what it contains, but rather in what it does not contain. Materials and Methods: In the present study attempts to investigate...

Tea is the most widely consumed beverage in the world. Tea leaves are a source of polyphenols, especially catechins, a decisive group for their antioxidative activity. This paper reviews what is known of green tea species, its leaves processing and changes occurring in tea components. The main green tea polyphenols are catechins: (±)-catechin C, (-)-epicatechin EC, (+)-gallocatechin GC, (-)-epi...