[Recent biochemical viewpoints on the development of tumors and the effect of nutrition]

DNA-analyses of the cytoblasts in many types of tumour cells show that in a considerable part an activation of certain protooncogens by mutation, translocation, amplification or deletion is present. Thus a dysregulation of the transcription is evoked. Changes in the structure of the protooncogens may be induced by numerous connections which are partly taken with the food and may be formed in the gastro-intestinal tract, respectively. In many forms of tumours an immunosuppression develops. In experimental animals the development of a tumour after administration of a carcinogen is furthered by a large content of the food of multifariously unsaturated fatty acids of certain chain length. A permanently unphysiologically high consumption of fat as well as of meat rich in fat and of sausages with simultaneously small intake of fruit and vegetables increases the risk of the formation of tumours of the colon and of the lactiferous gland. Aspects of the tumour prophylaxis concerning the physiology of nutrition are discussed.