Cancer

Cancer cells produce lactic acid even in the presence of adequate oxygen, a phenomenon known as the Warburg effect, which was first observed by Otto Warburg 1. This metabolic adaptation allows cancer cells to survive on protein and fats, rather than glucose 1. The Warburg effect is characterized by decreased oxidative phosphorylation, leading to impaired CO2 levels and increased lactate production 2.

The Warburg effect is part of a positive feedback cycle with the Randle cycle, where increased acidosis blocks glucose oxidation and increases fatty acid oxidation and synthesis 4. This vicious circle can be broken by providing extra glucose, which is a cheap and accessible method 4. The production of lactate, a byproduct of the Warburg effect, favors the oxidation of fat and can lead to the conversion of the body's own tissues to fuel the growth of cancer 5.

Recent studies have implicated lactic acidosis as a necessary and sufficient condition for cancerization of healthy tissue, and blocking systemic acidosis has been shown to have therapeutic effects, including shrinking primary tumors and preventing metastases 6. Lactate has been identified as an oncometabolite, promoting cancer without the need for genetic mutations 7. This suggests that cancer is a metabolic disease, rather than a genetic disorder.

The current understanding of cancer as a genetic disorder is being challenged by research that suggests that metabolic dysfunction, such as lactic acidosis, precedes and causes subsequent genetic mutations 7. This perspective is supported by the work of researchers who have shown that the Warburg effect drives oncogenesis, or the development of cancer 7.