Researchers in India have uncovered evidence to suggest drinking black tea could help prevent the development of oral cancer in subjects with leukoplakia, a disease that causes white spots to appear on mucous membranes on the tongue and in the mouth.
The preliminary results of a study at the Vivekananda Institute of Medical Sciences in Kolkata, published in the Journal of Environmental Pathology, Toxicology and Oncology, show that micronuclei frequency and chromosomal aberrations significantly decreased in the first 15 participants to complete a year-long program of drinking black tea ( Camellia sinensis ) three times a day.
Although the positive results relate to just a small group, they are consistent across all subjects who have completed the study so far. The results for another 67 participants will be available by April 2006.
Changes in the appearance and quantity of leukoplakia white spots in the mouths of the patients who have completed the study to date were also noted.
According to the researchers, oral carcinoma is the most common malignancy found in Indian men and the third most common in Indian women. In half of all cases, precancerous lesions, usually leukoplakia, appear prior to the development of full-blown cancer.
Most of the research into tea's potential for reducing the risk of various types of cancer has involved green tea which, although also derived from Camellia sinensis, contains different active compounds from black tea due to its production process.
For green tea, the leaves are steamed and dried, a procedure that preserves catechin polyphenols such as the powerful antioxidant epigallocatechin gallate (EGCG).
Black tea, on the other hand, is made by oxidizing the leaves, which converts the EGCG into other compounds. In the past scientists have unfavorably compared the benefits of compounds such as theaflavins and thearubigens to EGCG, but black tea is starting to gaining credence as a health-promoting preparation in its own right.
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