Can green tea slow cancer in smokers?

Green tea is made from leaves of the Camellia sinensis plant, which are heated after harvest to destroy enzymes that would break down catechins, natural antioxidant substances that may prevent or delay some types of cell damage.

A study by University of Illinois at Chicago researchers aims to determine whether green tea can inhibit the growth of cancer cells in smokers

Combined with the caffeine found in tea, catechins - especially the most active and abundant one, epigallocatechin-3-gallate - has been shown in animal models to be effective in preventing lung and other cancers.

Guy Adami and Joel Schwartz, associate professors of oral medicine and diagnostic sciences in the UIC College of Dentistry, hope to see whether green tea can induce a protective process of cell death called apoptosis, which occurs when cells of a living organism are damaged, for example by carcinogens.

The researchers will analyze RNA collected from cells in the mouth and cheek of study participants to determine, based on gene expression, cell pathways that are regulated by moderate levels of green tea consumption.

To enroll in the study, subjects must be between the ages of 20 and 45; smoke more than 10 cigarettes per day; have smoked for at least five years; and are willing to drink five cups of green tea each day.

In an earlier study, Schwartz discovered increased apoptosis in cells taken from the tongue of tobacco smokers after a month of exposure to the catechins from green tea.

''We believe the cathechins found in green tea are a possible daily preventative approach for head and neck cancers,'' Adami said.