Due to over-farming, chemical farming, processing, and refining, the nutrient content of much of our food is questionable. Thus, many believe that the majority of Americans are overfed and under-nourished. One key to stopping premature aging and preventing many degenerative diseases is for the body to be able to repair the damage that does occur. The other key is to protect the body's tissue cells from the free radicals before they cause mutations. They include any substance that significantly delays, inhibits, or prevents oxidation caused by free radicals.
Phytochemicals are literally chemicals that come from plants.
These plant chemicals fight many diseases. Many photochemicals are antioxidants, but they also have other properties, such as stimulating plant growth, and providing color to plants and flavor to vegetables. In humans, phytochemicals enhance the body's own healing powers. One free radical can damage a million or more molecules. This damage is called oxidative stress.