Summary of the abstract
Dietary Polyphenols, Inflammation, and Cancer
A considerable amount of evidence indicates that tumorigenesis is associated with inflammation. Nuclear factor-kappa B (NF-κ B), a master regulator of infection and inflammation, has been identified as a key modulator in which inflammation could develop into cancer. Dietary polyphenols have been shown to have anti-inflammatory and anticancer activity partially through inhibition of NF-κ B activation.
Phytonutrients in plants, especially those that inhibit NF-kappaB, reduce the risk of cancer
Even the federal government (USDA) recommends increasing your intake of fruits and vegetables, in part because a higher dietary intake (especially of dark green, deep yellow and other colorful fruits,) will reduce your risk of cancer.
It is reasonable that the government does not explain why this would be so. However, scientific evidence overwhelmingly suggests that fruits and vegetables reduce your risk of cancer because they contain phytonutrients that reduce inflammation, primarily via inhibition of NF-kB.