Scientists report that humans can be protected against the damaging effects of ultraviolet (UV) radiation by topical application of an extract of broccoli sprouts
/Broccoli Extract Reduces Redness, Inflammation Caused by Sun Exposure
Add sunscreen to the list of broccoli's health benefits. A new study suggests the potent vegetable may help protect the skin from sun damage.
Researchers found the compound sulforaphane, which is derived from broccoli sprouts, reduces the skin redness and inflammation caused by exposure to ultraviolet (UV) radiation.
Repeated sunburns are linked to a higher risk of skin cancer, and researchers say controlling the redness, known in medical terms as erythema, may be another way to fight skin cancer and sun-related skin damage.
Broccoli Skin Booster
In the study, researcher Paul Talalay of The Johns Hopkins University and colleagues examined the effects of sulforaphane on UV-induced erythema in six adults.
A solution containing sulforaphane derived from three-day old broccoli sprouts was applied to their skin before exposure to UV radiation using sun lamps.
The results showed the broccoli extract reduced redness by an average of 37% compared with untreated skin following UV exposure.
Researchers say the broccoli extract did not physically absorb the UV rays, but it appeared to work at the cellular level to prevent erythema. They say sulforaphane induces the formation of protective proteins in the skin and protects the skin from sun damage for several days.
Extract of broccoli sprouts protects against UV radiation
A team of Johns Hopkins scientists reports in this week's issue of the Proceedings of the National Academy of Sciences that humans can be protected against the damaging effects of ultraviolet (UV) radiation - the most abundant cancer-causing agent in our environment - by topical application of an extract of broccoli sprouts. The results in human volunteers, backed by parallel evidence obtained in mice, show that the degree of skin redness (erythema) caused by UV rays, which is an accurate index of the inflammation and cell damage caused by UV radiation, is markedly reduced in extract-treated skin.
Importantly, notes investigator Paul Talalay, MD, professor of pharmacology, this chemical extract is not a sunscreen. Unlike sunscreens, it does not absorb UV light and prevent its entry into the skin, so applying it to the skin will not give an immediate effect. Rather, the extract works more methodically, boosting the production of a network of protective enzymes inside skin cells to defend them against many aspects of UV damage. Consequently, the effects are long-lasting; the protection lasts for several days, even after the extract is no longer present on or in the skin.
As skin cancer incidence is rising dramatically due to the escalating exposure of aging populations to the UV rays of the sun, Talalay says 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 protective chemical agent in the broccoli sprout extracts is sulforaphane. It was first identified by Talalay and his colleagues more than 15 years ago and has been shown to prevent tumour development in a number of animals treated with cancer-causing chemicals.
After first testing mouse models of skin cancer to confirm sulforaphane's protective effects, Talalay and his team tested six healthy volunteers. Each one was exposed to a pulse of UV radiation on small patches of their skin (less than 1 inch in diameter) that were either treated or untreated with different doses of broccoli extract.
At the highest doses, UV-induced redness and inflammation were reduced by an average of 37 percent. The extracts were protective even when applied three days prior to UV exposure. The protection did vary considerably among the subjects, ranging from 8 percent to 78 percent, which Talalay notes may be due to genetic differences among individuals, local differences in the skin, or other factors such as dietary habits. He also points out that conventional sunscreens were essentially ineffective in these experiments.
This research was funded by the National Institutes of Health, American Cancer Society, American Institute for Cancer Research, and the Lewis B. and Dorothy Cullman Foundation. Authors on the paper are Jed Fahey, Zachary Healy, Scott Wehage, Andrea Benedict, Christine Min, Albena Dinkova-Kostova and Talalay, all of Johns Hopkins. Paul Talalay and Jed Fahey are unpaid consultants to Brassica Protection. Products LLC (BPP), which licenses the technology to produce broccoli sprouts. Talalay, Fahey and The Johns Hopkins University are equity owners in BPP (whose chief executive officer is Antony Talalay, son of Paul).