Whereas much attention is focused on distinguishing newly diagnosed prostate cancers that will progress to become aggressive forms of the disease from those that will remain indolent, it is also appropriate to explore therapeutic and lifestyle interventions to reduce the risk of progression. Diets rich in broccoli have been associated with a reduction in risk of progression, which has been attributed to the compound sulforaphane. Although the mode of action of sulforaphane has been extensively studied in cell and animal models and a multiple of mechanisms that could underpin its protective effects have been proposed, recent evidence from human intervention studies suggests that sulforaphane is involved in a complex interplay between redox status and metabolism to result in a tissue environment that does not favour prostate cancer progression.