Media reports on the BBC and other websites commented on promising research on the use of green tea to prevent progression of prostate cancer.

This story was based on a research report from the US in which researchers carried out an "open-label" study on 26 patients scheduled for prostatectomy.  There was no control group (they all got the same treatment).

"Open-label" means that the researchers and patients all knew that they had received an active treatment (as opposed to a placebo, which was not used.)

The researchers found that patients given polyphenols (chemicals which are found in green tea) subsequently had lower levels of important biological markers of prostate cancer.

NHS Choices commented:

"Taking the Polyphenol E capsule led to a significant reduction in the blood levels of certain chemicals that are considered to be markers of the severity of prostate cancer. The authors suggest that this change in chemical levels may reflect a slowing down of the progression of disease. However, an actual slowing of the disease's progression has yet to be proven as this study did not assess clinical outcomes of the patients."

This is good news:  hopefully it means we will soon see larger-scale, longer-term studies of green tea and related compounds which assess clinical outcomes.

• NHS Choices' Behind the Headlines story

• Read the abstract of the publication in Cancer Prevention Research
  
• Comment from The Prostate Cancer Charity