Researchers from Johns Hopkins University who worked on the study say broccoli contains a chemical called sulphoraphane which activates cancer fighting enzymes in the cells. The highest concentration of sulphoraphane is to be found in broccoli sprouts.
According to Voice of America (VoA), as part of the research, the scientists smeared extract from broccoli sprout on six volunteers for three days and then exposed them to high levels of ultraviolet radiation. Exposure to this type of radiation is the leading cause of skin cancer.
Findings showed the skin patches covered by broccoli sprout extract exhibited 37 percent less redness and sunburn; redness and sunburn are two indicators of skin damage which could result in skin cancer.
However, people should not stop using sunscreen altogether.
Paul Talalay, molecular pharmacologist and the author of the study, told VoA: "We want to avoid under all circumstances people doing weird things like making broccoli sprout soup and applying to their skin and thinking that they will be protected against the sun. They will have not have [sic] any protection whatsoever, because it's a totally different mechanism and one cannot possibly substitute for the other."
Sunscreen works by deflecting sun's harmful rays while extract from broccoli sprout gets under the skin cells and stimulates their cancer-fighting mechanism.
Talalay said the study's finding was supported by similar evidence from research on mice.
He also believes that sulphoraphane can work against cancer in other organs if it works on skin.
Part of the cabbage family, broccoli is already known as a good source of vitamin A, vitamin C and fiber.
Commercial products using the extract, like sun cream, are currently being researched.
