There is no scientific evidence to support a direct link between the relationship of an alkaline diet and cancer, according to Nutrition and Metabolism. The article "Examining the Relationship Between Diet-Induced Acidosis and Cancer" is considered to be the most comprehensive review available, according to Authority Nutrition, as of 2012.
Proponents of the alkaline diet argue that cancer only grows in an acidic environment and that cancer can be both treated and cured with it. Food cannot influence the pH levels of blood, according to the journal article. Even if it could, cancer cells can grow in alkaline and neutral environments too.