U.S. researchers have discovered that as well as being healthy food, broccoli also helps skin cells fight off damage caused by harmful ultraviolet radiation.
The researchers say an extract from newly sprouted broccoli seeds reduced skin redness (erythema) and damage by more than one-third compared with untreated skin and the extract has already been shown to help skin cells fight UV damage in mice.
The team from Johns Hopkins University say this is the first time it has been seen that human tissue can be protected directly against a known human carcinogen.
Dr. Paul Talalay who led the study says the extract is not a sunscreen, but instead helps fortify skin cells to fight the effects of UV radiation.
Dr. Talalay says unlike sunscreens, which provide a physical barrier against UV rays by absorbing, blocking or scattering the light, the extract helps boost the production of protective enzymes that defend against UV-related damage.
Dr. Talalay has been studying the compound in broccoli sprout extract, sulforaphane, for more than 15 years and says it has been shown to prevent tumor development in a number of animals treated with cancer-causing agents.
For the study Talalay and his colleagues tried the extract on six people; they tested different doses of the extract on several small patches of skin, which was then exposed to a short pulse of UV radiation sufficient to cause varying degrees of sunburn.
The redness of the skin in the treated and untreated areas was then compared as redness is a measure of a series of processes that go on in the skin which are harmful, including DNA damage.
They found that the highest doses of the extract reduced redness and swelling by an average of 37 percent and the effect was long-lasting.
Talalay says there was still an effect two days after the treatment was stopped.