[How useful are diets against cancer?].

BACKGROUND: Diets against cancer are attractive for patients who try to influence disease progression.

METHODS: In order to determine the most influential cancer diets in Germany, we analyzed the chatroom for cancer patients "Krebs-Kompass", the search machines Google and Bing and our own counseling experience as experts. We conducted a systematic literature review of clinical data in Medline also considering preclinical data on safety.

RESULTS: The most often mentioned "cancer diets" are Budwig diet, Gerson's regimen, lowcarb diet, cancer cure of Breuß and macrobiotic diet. These diets can be classified according to the principle idea of carcinogenesis as follows: cancer as a lack or abundance of a substance or as a consequence of pathological metabolism of cancer cells. Staying in line with a specific diet the patients are thought to be able to cure themselves or at least substantially contribute to cure. However, we did not find any scientific publication of a clinical study which describes positive results regarding survival. On the contrary, data show malnutrition and side effects.

CONCLUSION: There is no indication to consume a "cancer diet". In some cases adverse effects can occur. Cancer patients who are discussing nutrition should be warned about taking up a "cancer diet".