THURSDAY, Nov. 30 (HealthDay News) -- Tea extracts can help reduce skin damage caused by cancer radiation therapy, according to a study by American and German researchers.

They examined the effects of green tea and black tea extracts and found that they reduced the duration of radiation-induced skin damage by five to 10 days. The tea extracts work at the cellular level to inhibit inflammatory pathways and reduce inflammation, said the team from the University of California, Los Angeles, and the University of Freiburg.

As well as testing the extracts on patients, the researchers studied the effects of green and black tea extracts on human and mouse white blood cells in laboratory cell cultures.

They found that the extracts reduced the release of pro-inflammatory cytokines, such as IL-1beta, IL-6, IL-8, TNF-alpha and PGE2, in human white blood cells. Green tea extract appeared to have higher anti-inflammatory properties than black tea extract.

Both green and black tea extracts inhibited one major inflammatory pathway in mouse white blood cells.

The researchers said that the high amount of polyphenols in tea is likely responsible for its anti-inflammatory activity, but added that other pathways are likely involved in its clinical effectiveness.

The study is published in the journal BMC Medicine.