Oral cancer represents 2-4% of all diagnosed cancers, showing an annual increase of 5,000 new cases. Unfortunately, due to delays in diagnosis the 5-year survival rate is only 25%. For this reason, any measures to restrict the consumption of tobacco and alcohol and that will help preserve oral health and maintain a balanced diet will lead to benefits in terms of a reduction in the occurrence of this pathology. There are many articles that warn us of the implications of smoking, of oral infections from Candida or papillomavirus, of the consequences of iron or folic acid deficiencies, all elements considered to favour the development of oral cancer. On the other hand, less well known are dietary aspects, the study of which called our attention. In this article we summarize some of the more relevant knowledge on carcinogenesis and the phases in which certain groups of foods and nutrients act as preventive factors.