The one thing on which all nutritionists seem to agree is that consumption of vegetables and fruit helps fight many chronic diseases.
"It is often said that phytochemicals are to the twenty-first century what vitamins were to the twentieth. Just as the intensive study of vitamins led to a new understanding of nutrition, so research on phytochemicals will lead to a new science of prevention through diet," said AICR Nutrition Advisor Karen Collins, RD.
Perhaps the best known function of phytochemicals is elimination of free radicals that can cause DNA damage leading to cancer. In fact, phytochemicals act in at least eight different ways we know of to reduce cancer risk. These ways range from causing spontaneous cancer cell death (apoptosis) to regulating hormones: http://www.infozine.com/news/stories/op/storiesView/sid/15953/.
[Note: Phytochemicals (phytonutrients) are found ONLY in plants. Meat, dairy and eggs do NOT contain them. Most processed foods have very little or none. Eat a diet of mostly local, organic, whole unprocessed plant foods for the best health!]