Characteristics and Health Benefits of Phytochemicals.

In food science the term 'phytochemicals' includes a variety of plant ingredients with different structures that are capable of health-promoting effects. Phytonutrients are natural substances but are not called nutrients in the traditional sense, since they are synthesized by plants neither in energy metabolism nor in anabolic or catabolic metabolism, but only in specific cell types. They differ from primary plant compounds in that they are not essential to the plant. Phytonutrients perform important tasks in the secondary metabolism of plants as repellents to pests and sunlight as well as growth regulators. They occur only in low concentrations and usually have a pharmacological effect. Since antiquity, these effects have been used in naturopathy in the form of medicinal herbs, spices, teas, and foods. With the development of highly sensitive analytical methods, a variety of these substances could be identified. These phytochemicals may have health benefits or adverse health effects, depending on the dosage. In the past, these effects were studied in cell and tissue cultures as well as in animal models. Meanwhile there are numerous epidemiological data that point to the extensive health potential of phytochemicals in humans. A high dietary intake of phytochemicals with vegetables, fruits, nuts, legumes, and whole grain is associated with a reduced risk for cardiovascular and other diseases.