Phytochemicals are commonly referred to as phytonutrients and in fact used interchangeably by most. Phytochemicals are chemical compounds found in plants that are not needed for normal functioning in humans but which contain protective, disease-preventing properties. In other words, phytochemicals carry no nutritional value for human beings but do benefit humans by protecting us from diseases like cancer.

There are over 1,000 known phytochemicals and it is estimated that just one serving of vegetables may contain over 100 phytochemical compounds. Plants produce phytochemicals to protect themselves but recent discoveries have shown that phytochemicals also protect humans. Some of the well-known phytochemicals are isoflavones in soy, lycopene in tomatoes and flavanoids in fruit.

Many of the known phytochemicals work as antioxidants, stimulate enzymes, interfere with DNA replication, have an antibacterial effect and imitate hormones. Phytochemicals with antioxidant properties may be found in fruits and vegetables such as grapes, carrots, onions, leeks and garlic to name a few.

The phytochemical found in cabbage, indoles, stimulate enzymes that interact with estrogen and has been linked to a reduced risk for breast cancer. Beans contain a phytochemical named 'saponin' which interferes with the replication of cell DNA, inhibiting the multiplication of cancer cells. Garlic's phytochemical, allicin, has been shown to have antibacterial properties. Soy contains the isoflavones phytochemical, which imitates human estrogen, reducing symptoms of menopause and osteoporosis.

Four of the leading causes of death in the United States, cancer, diabetes, cardiovascular disease, and hypertension are associated with phytochemicals for prevention or treatment of these diseases. The easiest ways to get more phytochemicals into our diets is to eat more fresh fruits, vegetables, whole grains, beans and through supplementation. The USDA recommends 5 to 9 servings per day of fresh fruits and vegetables, while most people average 1 to 2 servings. One survey conducted showed that one in nine American ate not fruit or vegetables on the day the survey was taken.