A clinical trial involving nearly 300 Chinese men and women residing in one of China’s most polluted regions found that daily consumption of a half cup of broccoli sprout beverage produced rapid, significant, and sustained higher levels of excretion of benzene, a known human carcinogen, and acrolein, a lung irritant. Researchers from the Johns Hopkins Bloomberg School of Public Health, working with colleagues at several U.S. and Chinese institutions, used the broccoli sprout beverage to provide sulforaphane, a plant compound already demonstrated to have cancer preventive properties in animal studies. The study was published in the June 9 online edition of the journal Cancer Prevention Research.
“Air pollution is a complex and pervasive public health problem,” notes Dr. John Groopman, Anna M. Baetjer Professor of Environmental Health at the Johns Hopkins Bloomberg School of Public Health and one of the study’s co-authors. “To address this problem comprehensively, in addition to the engineering solutions to reduce regional pollution emissions, we need to translate our basic science into strategies to protect individuals from these exposures. This study supports the development of food-based strategies as part of this overall prevention
The 12-week trial included 291 participants who live in a rural farming community in Jiangsu Province, China, approximately 50 miles north of Shanghai, one of China’s more heavily industrialized regions. Participants in the control group drank a beverage made of sterilized water, pineapple and lime juice while the beverage for the treatment group additionally contained a dissolved freeze-dried powder made from broccoli sprouts that contained glucoraphanin and sulforaphane. Sixty-two men (21 percent) and 229 women (79 percent) with a median age of 53 (ranging from 21 to 65) years were enrolled in the study. Urine and blood samples were taken over the course of the trial to measure the fate of the inhaled air pollutants.
The research team found that among participants receiving the broccoli sprout beverage, the rate of excretion of the carcinogen benzene increased 61 percent beginning the first day and continuing throughout the 12-week period. In addition, the rate of excretion of the irritant acrolein, rapidly and durably increased 23 percent during the 12-week trial. Secondary analyses by the investigators indicated that the sulforaphane may be exerting its protective actions by activating a signaling molecule, NRF2, that elevates the capacity of cells to adapt to and survive a broad range of environmental toxins. This strategy may also be effective for some contaminants in water and food.