Dr. Elias Petrou, a Greek doctor and physiotherapist, came from America in 1935 where he studied and with a series of books he wrote and corresponding lectures he managed to change Greek society within a few years. His own actions with treatments of people suffering from serious or non-serious illnesses, within a few days and mainly in a natural way, made the Greeks believe in him and talk about the new "revolution" of natural hygiene. The therapeutic methods he applied were based on the following:
- Fasting for detoxification and correction of intestinal function, from where most diseases originate according to natural hygiene and natural therapeutic science.
- Fruit therapy for natural toning of the body, treating many diseases but also as a smooth re-entry into the diet after fasting.
- Alkaline diet for correction and increase of pH in the blood, as a means of prevention so that we do not get sick.
- Physical exercise for the proper functioning of the muscles and the elimination of toxins through burns from the body.
- Aerotherapy through exposure to clean environment and respiratory exercises.
- Heliotherapy through exposure to the sun -obliquely in the shade and not directly- with measure but steadily throughout the year, in order to acquire the bronze color that is indicative of a healthy person as he said, (not the sickly one of the solarium, nor the excesses of the sun).