Mayo clinic researchers
in Rochester, Minn., report the conditions of some chronic leukemia patients
may improve by taking an extract of green tea.
In the small case study, the researchers
report four patients with chronic lymphocytic leukemia appeared to have
an improvement in the clinical state of their disease after consuming over-the-counter
products containing epigallocatechin gallate, or EGCG, an extract of green
tea.
Three of the four patients met the standard
criteria used to define a response treatment for clinical trials.
The same investigators had previously shown
EGCG kills leukemia cells from such patients in the test tube by interrupting
the communication signals they need to survive. That study was published
in the journal Blood in 2004.
Dr. Tait Shanafelt, Mayo Clinic hematologist
and lead author of the most recent article, urges caution. "We do not know
how many patients were taking similar products and failed to have any benefit.
We also do not yet know the optimal dose
that should be used, the frequency with which patients should take the
medication, and what side effects will be observed with long-term administration."
The findings are published online in Leukemia
Research.
