Cancer metabolism

Cancer metabolism is a complex process involving an imbalance of the organism's demands and resources, leading to an excess of adaptive hormones. This results in the production of lactic acid, increased cortisol, and a shift to the consumption of fat and protein rather than glucose 2. The Randle effect, a process in which free fatty acids inhibit glucose oxidation, is activated by increased cortisol, accelerating the breakdown of protein into amino acids and producing fatty acids from amino acids and pyruvate 2.

The Warburg effect, observed by Otto Warburg, describes how cancer cells produce lactic acid even in the presence of adequate oxygen. This is not because cancer cells "live on glucose," but rather because they are highly adapted to survive on protein and fats 4. The Pasteur effect, which normally restrains glycolysis in the presence of adequate oxygen, is also relevant to cancer metabolism 4.

Ray Peat argues that sugar starvation does not starve cancer, but rather causes the Randall cycle to take effect, blocking the ability to oxidize sugar fully and promoting cancer metabolism 1. Peat also notes that once the body is in a ketogenic state due to starvation, it is unable to fully oxidize glucose, leading to the production of lactic acid and the shift to cancer metabolism 5.

Georgi Dinkov and Danny Roddy discuss the role of lactic acid in cancer metabolism, noting that it is a potent inducer of tumors and can create a state of virtual hypoxia, leading to the activation of cancer metabolism 6. Dinkov also notes that cancer cells can express both fatty acid synthase and mitochondrial fatty acid oxidation simultaneously, which is irregular and may be driven by the overactivation of mitochondrial β-oxidation 7.

In contrast to the common view that cancer cells "live on glucose," Peat and others suggest that cancer is an attempt to heal a tissue, and that providing glucose to the tumor in sufficient amounts can actually help to dissolve the tumor 8.