TUESDAY October 23, 2007 (Foodconsumer.org) -- Ultraviolet (UV) radiation damages the skin and raises cancer risk. But a new study showed that topical application of an extract of broccoli sprouts reduced the skin cancer risk associated with UV-induced inflammation, according to Johns Hopkins scientists who reported the finding in this week’s issue of the Proceedings of the National Academy of Sciences.
The tested broccoli sprout extract, which is not a sunscreen, according to the researchers, reduced the UV-induced redness and inflammation, which is the accurate indicator of cell damages, by up to 37 percent on human skin when a high dose was used, according to the researchers.
The study was conducted by Paul Talalay, M.D., professor of pharmacology.
He and colleague Jed Fahey and The Johns Hopkins University are equity owners in Brassica Protection Products LLC (BPP), which licenses the technology to produce broccoli sprouts.
Unlike sunscreens, the extract does not block entry of UV light and prevent absorption of UV rays by the skin.
Instead, the extract gets into the skin and boosts production of certain protective enzymes that help defend cells against many types of UV damage. This means that the protective effect can last several days even after it disappears from the skin.
With skin cancer incidence on the rise and the protective effect of common sunscreens in doubt, Talalay said that “treatment with this broccoli sprout extract might be another protective measure that alleviates the skin damage caused by UV radiation and thereby decreases our long-term risk of developing cancer.”
The active ingredient in the broccoli sprout extract is a chemical known as sulforaphane, which was first identified by Talalay and his colleagues more than 15 years ago, according to the news release by Johns Hopkins Medical Institutions. This compound has been found to have other protections against tumor development induced by carcinogens as showed in a number of animal studies.
The protective effects of sulforaphane against skin cancer were initially tested in mouse models.
The extract was also tested in six healthy people on their skin in the study. Each individual was exposed to a pulse pf UV rays on small patches of their skin that was treated or untreated with different doses of broccoli extract, according to a news release by Johns Hopkins.
The protection of the broccoli sprout extract was still effective when the extract was applied on the skin three days prior to the exposure to the UV radiation.
In contrast, conventional sunscreens were ineffective in these experiments.
However, the magnitude of the protective effect varied from person to person depending upon certain genetic makeup, location of exposed skin, and other factors such as dietary habits.
Sulforaphane found in broccoli has been studied as a chemoprevention agent and it potentially protects against a number of cancers.
For instance, the compound induces cell type-specific apoptosis in human breast cancer cell lines, according to a study by who published their findings in the March 2007 issue of Molecular Cancer Therapy.