Dr. Thomas Rau, father of Swiss Biological Medicine, explains that repairing the internal milieu is central to restoring health. The internal milieu is comprised of blood, lymph, and the interstitial fluids that surround and bathe our cells and whose state or condition is represented by pH (acidity) and tissue oxygenation, which determine whether natural creative or destructive processes occur within the body. The nutritional status within this milieu is the primary determinant for either health or disease processes, and bacteria are drawn to diseased cells, tissues, and organs as scavengers but not the causes of disease. Thus, Biological Medicine focuses on treating the internal milieu to restore metabolic processes to their full functionality and to support healthy mitochondrial function that is necessary for the energy required to drive all biological processes in the body.

In Biological Medicine, nutrition is one of its foundational treatment strategies because all people require energy for their survival, and energy from the world/universe is stored within foods via sunlight, the soil, and water. Healthy, organic foods that have experienced minimal modern industrial processing are best suited to restore lost health and maintain health. We are what we eat is an exceptionally appropriate phrase to convey the importance and the power contained in properly grown foods and in drinking clean water.