A green tea extract is showing promising results in early leukemia clinical trials, according to a new report.

Mayo Clinic researchers have tested an active ingredient in green tea called epigallocatechin gallate (EGCG) to determine its impact on patients with chronic lymphocytic leukemia (CLL).

In the first phase of the trial, a total of 33 patients received oral doses of Polyphenon E, a proprietary compound whose primary active ingredient is EGCG. Doses ranged from 400 milligrams to 2,000 mg administered twice a day.

“We found not only that patients tolerated the green tea extract at very high doses, but that many of them saw regression to some degree of their chronic lymphocytic leukemia,” says Dr. Tait Shanafelt, Mayo Clinic hematologist and lead author of the study.

“The majority of individuals who entered the study with enlarged lymph nodes saw a 50 percent or greater decline in their lymph node size,” he adds.

The research has now moved to a second phase where participants will receive higher doses of the medication.

Green tea has a proven range of health benefits including relieving inflammation. Those who would like to enhance their diet with the antioxidant compounds found in green tea may turn to nutritional supplements.