Cancer Loves Sugar – Truth or Rumor?

This familiar saying, "cancer loves sugar" has been around since the 1924 publication of Dr. Otto Warburg's paper, "On metabolism of tumors." Warburg was a Nobel Prize winning cell biologist who wrote, "Summarized in a few words, the prime cause of cancer is the replacement of the respiration of oxygen in normal body cells by a fermentation of sugar." Many people who referred to his work in later years misquoted Warburg's statement by saying, "cancer loves sugar."
Warburg's hypothesis stated that cancer growth was caused when cancer cells converted glucose into energy without using oxygen. Healthy cells make energy by converting pyruvate and oxygen. The pyruvate is oxidized within a healthy cell's mitochondria, and Warburg theorized that since cancer cells don't oxidize pyruvate, cancer must be considered a mitochondrial dysfunction.
Now that we know more about the genetics of cancer, we know that cancer is not a mitochondrial dysfunction, but is caused by genetic mutations, such as appear on the genes BRCA1 and BRCA2. It is true that healthy cells and cancer cells convert their food to energy in different ways, but that difference is an effect, and not a cause, of cancer.