The study, published in the November issue of Cancer Epidemiology Biomarkers & Prevention, was conducted by a team from Johns Hopkins University School of Medicine and Bloomberg School of Public Health, in collaboration with scientists from cancer institutes in Shanghai and Minnesota.
It is understood that this is the first report to provide direct evidence that broccoli sprouts can enhance the body’s detoxifying system to help prevent cancer.
The blinded, placebo-controlled study was conducted in Jiangsu Province near Shanghai, a rural area where the incidence of liver cancer is extremely high due to consumption of foods tainted with aflatoxin, a powerful carcinogen produced by mold contaminating the grain that the population grows and eats. The toxin binds to DNA and becomes a chemical indicator, or biomarker, for an increased risk of developing liver cancer.
Three-day-old broccoli sprouts with known levels of sulforaphane glucosinolate (SGS) were grown at the site in China and prepared as a liquid extract to ensure standard dosages. One hundred test subjects drank five ounces of the extract – equivalent to eating about two ounces of broccoli sprouts – each day for two weeks. A control group drank a similar extract that contained virtually no SGS.
Tests of subjects’ urine showed carcinogens were being detoxified and removed from the body in those who drank the SGS extract. As the levels of sulforaphane derivatives in the urine increased, the amount of DNA damage decreased, which may indicate a reduction in cancer risk.
“While this study did not directly look at liver cancer, it is clear that liver cancer has had devastating consequences in this region of China and in other parts of the world,” said participating epidemiologist Dr Jian-Guo Chen from the Qidong Liver Cancer Institute. “This study is an initial step in evaluating dietary methods for preventing this disease, and it may be applicable to other types of cancers,” said.
Further studies are in the planning phases to examine dose levels and implications for other high-risk populations.