July 26, 2010 – A green tea extract highly concentrated in antioxidants would stabilize chronic lymphocytic leukemia in those for whom the disease is in the first stage.
In a small-scale study without a control group, 42 people with chronic lymphocytic leukemia (CLL) took the equivalent of 4 g of a green tea extract daily with a large dose of antioxidants from the family of catechins2.
This is a product called Polyphenon E, which is not yet marketed in Canada or the United States.3.
After 6 months, 2 in 3 (66%) patients saw a reduction of at least 50% in the activity of their lymph nodes, while 1 in 2 (52%) saw the number of lymphocytes (“deregulated” white blood cells) decrease by at least 20%.
Note that the study was conducted with patients whose leukemia was in its early stages (0 to 2) and who were not yet experiencing any symptoms of the disease. Their condition was not sufficiently advanced to be subjected to chemotherapy treatment.
Asked about the magnitude of the observed therapeutic effect, lead author Tait D. Shanafelt explained that it was “sufficient to stabilize the disease”. In a next phase of the study, he wants to “check whether green tea extract can delay taking chemotherapy drugs”.
In addition, the side effects of Polyphenon E were rather mild in intensity and manifested mainly by stomach aches, nausea, diarrhea and fatigue.
According to pharmacist Jean-Yves Dionne, these side effects can just as easily result from the leukemia itself as from taking green tea extract.
What about other green tea extracts?
Polyphenon E is not available on the shelves, but other green tea extracts – also containing catechins – are available on the market.
Nevertheless, Tait D. Shanafelt and Jean-Yves Dionne urge people with chronic lymphoid leukemia to consult their oncologist or their doctor before obtaining such an extract.
“If a person with leukemia is taking green tea extract supplements, it is important that they be monitored so that they are regularly tested for their effect in the blood and on the liver, in particular,” Shanafelt said.
Indeed, although they were of low intensity, the undesirable effects observed on the liver, during the study, deserve to be taken into account, concluded the researcher.
Martin LaSalle – PasseportSanté.net
1. Shanafelt TD, et al, Phase II trial of daily, oral green tea extract in patients with asymptomatic, Rai stage 0-II chronic lymphocytic leukemia (CLL), Journal of Clinical Oncology, 2010 ASCO Annual Meeting Proceedings (Post-Meeting Edition), vol. 28, no 15_suppl (May 20 Supplement), 2010; 6522.
2. The catechin used in this extract is called “epigallocatechin gallate” (EGCG). EGCG is one of the main substances contributing to the health benefits of green tea. For more information, see our Green tea fact sheet.
3. Polyphenon E is a product created by the company Polyphenon Pharma: www.polyphenon-pharma.com [site consulté le 23 juillet 2010].
