Research supports the hypothesis that one's diet has a great impact on his or her risk of cancer. Many studies have found that increased fruit and vegetable intake decreases the risk of cancer. Cruciferous vegetables such as broccoli and cauliflower seem to be especially protective against cancer. Most studies show that phytochemicals in crucifers up-regulate many detoxification enzyme systems in the animal that consumes them. Recent reports of the molecular events involved in the activation of a gene promoter called the antioxidant responsive element have begun to provide clues as to how a single substance may induce a battery of many genes.