It’s all a bit more complicated, of course, than the picture I posted above, as lactic acid leaving the cell makes it internally more alkaline, and the lactic acid now outside the cell, allows damaging polyunsaturated fats to enter the cell, damaging the mitochondria and suppressing respiration. Cells should normally be internally acidic with an alkaline halo, constituting the charge separation of the membrane electrical bilayer and the capacitor-like/stored potential energy of the cell. Here’s a quote from Ray Peat, with his usual contrarian take on how starving the cancer cell of glucose isn’t a good way to get rid of it because you would starve yourself before you’d successfully starve the tumour... “The increased intracellular alkalinity and intracellular calcium that result from the combination of those factors increase the tendency of cells to be overstimulated, leading to aerobic glycolysis, the cancer metabolism. Improving any part of the system tends to increase carbon dioxide and decrease lactate, permitting differentiated functioning. There are many people currently recommending fish oil (or other highly unsaturated oils) for preventing or treating cancer, and it has become almost as common to recommend a sugar free diet, "because sugar feeds cancer." This is often, incorrectly, said to be the meaning of Warburg&#39;s demonstration that cancer cells have a respiratory defect that causes them to produce lactic acid from glucose even in the presence of oxygen. Cancer cells use glucose and the amino acid glutamine primarily for synthetic purposes, and use fats as their energy source;the growth stimulating effect of the "essential fatty acids" (Sueyoshi and Nagao, 1962a; Holley, et al., 1974) shows that depriving a tumor of those fats retards its growth. The great energetic inefficiency of the cancer metabolism, which causes it to produce a large amount of heat and to cause systemic stress, failure of immunity, and weight loss, is because it synthesizes fat from glucose and amino acids, and then oxidizes the fat as if it were diabetic. Estrogen, which is responsible for the fact that women burn fatty acids more easily than men, is centrally involved in this metabolic inefficiency. When a tissue is exposed to estrogen, within minutes it takes up water, and begins to synthesize fat, with a tendency to produce lactic acid at the same time. The alkalizing effect of lactic acid production is apparently what accounts for the uptake of water. Since it takes longer, at least 30 minutes, to produce a significant amount of new enzymes, these early changes are explained by the activation of existing enzymes by estrogen. The transhydrogenases, or the transhydrogenase function of the steroid dehydrogenases, which shift metabolic energy between glycolytic and oxidative systems, have been shown to explain these effects of estrogen, but the transhydrogenases can be activated by many stressors. The biological function of the transhydrogenases seems to be to allow cells to continue growth and repair processes in a hypoxic environment. Estrogen can start the process by creating new pathways for electrons, and will promote processes that are started by something else, and progesterone is estrogen&#39;s natural antagonist, terminating the process. Recently, a group at Johns Hopkins University (Le, et al., 2012) has been working out the implications of this ability to change the metabolism under hypoxia: Using an isotope-labeled amino acid, ". . . glutamine import and metabolism through the TCA cycle persisted under hypoxia, and glutamine contributed significantly to citrate carbons. Under glucose deprivation, glutamine-derived fumarate, malate, and citrate were significantly increased." The implication of this is that if the tumor isn&#39;t supplied with sugar, it will increase the rate at which it consumes the host&#39;s proteins.” <a href='http://raypeat.com/articles/articles/cancer-disorder-energy.shtml'>http://raypeat.com/articles/articles/cancer-disorder-energy.shtml</a>