Lactic acid

Lactic acid (lactate in blood chemistry) is produced when glucose is not fully oxidized to CO₂ in the mitochondria. Under oxygen, cells normally restrain glycolysis so glucose becomes CO₂ (Pasteur effect); cancer and stress keep making lactic acid anyway (Warburg effect), and lactate can then inhibit respiration (Crabtree effect). Cancer cells are highly adapted to survive on protein and fats, not "living on glucose."

Lactate appears in rosacea, arthritis, heart disease, diabetes, neurological disease, and cancer; suppressing it can be curative after fifty years of denial that treated it only as a marker. See CO2, Mitochondria, Stress, Randle cycle.

Stress metabolism

Lactate and inflammation promote each other in a vicious cycle. In 10 patients with mitochondrial DNA mutations, lactate levels and production during cycling were several-fold higher than in controls, yet working muscle oxidized lactate to the same extent.

Stress metabolism pairs excess adaptive hormones with depleted glucose, rising lactate and cortisol, and a shift toward consuming fat and protein rather than glucose; cortisol activates the Randle effect and fatty acid synthase.

Political turn away from respiration

Through the 1920s, work by Otto Warburg and Albert Szent-Györgyi put respiration at the center of cancer and metabolism. After the wars, U.S. research financing concentrated on genetic and viral interpretations; nutrition was said not to matter once calories and a vitamin minimum were met.

Hartmann and hospital lactate

Johann Joseph Scherer first demonstrated lactic acid in human blood in shock in January 1843.

In 1932 Alexis Hartmann injected sodium lactate into acidotic patients, some of whom already had excess lactate; hospital lactate solutions became standard and helped deny lactate's toxicity. Methylglyoxal can form from D- or L-lactate (and from MDA of lipid peroxidation) and glycates proteins; aging and diabetes get framed around glucose instead.

Vessels, matrix, clotting, brain

Lactate causes vasodilation and edema, stimulates collagen synthesis, and drives neovascularization even when oxygen is present, disrupting the matrix cells need to stay differentiated. It increases blood viscosity, promotes red-cell aggregation ("blood sludge"), leaks endothelium via VEGF/VPF, and can break down the blood-brain barrier. Lactated Ringer's contributes to shock tissue damage; hypertonic saline (and sometimes hypertonic glucose) has compared favorably.

Koch and the respiratory defect

W.F. Koch held that restoring efficient oxygen use could correct cancer metabolism and that a respiratory defect drove immunodeficiency, allergy, and failed muscle, nerve, and gland function, colliding with the doctrine of genetic irreversibility; Szent-Györgyi pursued lactate metabolites and oxidation without naming Koch during the U.S. campaign against him.

Fat-synthesis sink

When mitochondria cannot consume pyruvate, it becomes lactate; backed-up lactate feeds fat synthesis. Fatty acid synthase is high in cancers (worse outlook with more of it); cortisol and estrogen induce it.

Ammonia loop

Glycolysis is a poor energy yield, and the liver spends energy turning lactate back into sugar. The resulting hypoglycemia raises cortisol, which frees amino acids and free fatty acids that block glucose use. Ammonia rises while less CO₂ is available to convert ammonia to urea; ammonia stimulates lactate, CO₂ inhibits it.

Tumors, fasting, stem cells

Fasting an animal with a tumor can speed the tumor; tumors grow by recruiting stem cells that fail to differentiate in a lactate-rich, CO₂-poor matrix.

Opposing stack

Practical opposition to the high-lactate stress pattern includes vitamin B1 / thiamine (raise CO₂, cut lactate), niacinamide (lower free fatty acids), sugar, salt, and thyroid hormone (raise CO₂); vitamins D, K, B6, and biotin sit on related CO₂ axes. Dietary protein should be adequate without excess tryptophan, because serotonin increases inflammation and glycolysis.

Hard exercise while fasted and gut endotoxin raise lactate and nitric oxide, impair mitochondria, and favor estrogen accumulation; salt protects while lactate solutions harm. Aspirin interrupts excitotoxic and growth signals tied to that cascade. Dichloroacetate can stop lactate production by blocking glycolysis but is pursued as a toxic drug path; correcting respiration is the preferred frame.

How it rises

Free fatty acids block glucose oxidation. Polyunsaturated free fats are the worst. The cell still takes in sugar and turns it to lactate.

Low thyroid, hyperventilation (low CO₂), endotoxin, estrogen, and hard over-breathing raise the same pattern. See Thyroid, Endotoxin, Estrogen.

Altitude and CO₂

CO₂ from full oxidation opposes the leaky, swollen, high-lactate state. After acclimatization to high altitude, peak exercise lactate falls (the "lactate paradox"): similar at sea level (11.0 mmol/L) and on acute severe hypoxia (9.9 mmol/L), then 5.6 mmol/L after one week at 5,400 m, partly rebounding to 7.8 mmol/L by four weeks.

Buffering acid load with sodium bicarbonate

Sodium bicarbonate before exercise alkalizes blood and can improve muscular endurance in meta-analyses, without improving strength; typical studied doses are 0.2–0.4 g/kg. That buffers acid after glycolysis rather than restoring CO₂-producing sugar oxidation.

Resistance exercise and cognition

One moderate resistance session raised blood lactate from 1.38 to 8.22 mmol/L (rest group 1.37 to 1.91) in an acute randomized between-subjects trial of 121 adults aged 18–50, with individual post-exercise values from 2.8 to 18.3 mmol/L. Flanker and N-back response times improved, and exploratory mediation did not support lactate as the path; the systolic blood pressure rise did. See Brain.

Dichloroacetate

Dichloroacetate (DCA) is a small-molecule drug that inhibits pyruvate dehydrogenase kinase (PDK), which normally suppresses pyruvate dehydrogenase (PDH). By releasing that brake, DCA pushes pyruvate into full mitochondrial oxidation rather than conversion to lactic acid, reversing the Warburg-style glycolytic shift seen in many cancer cells.

Dosing

DCA for cancer was described as "essentially non-toxic in moderate amounts," similar to methylene blue in that respect. The cited account records people taking as much as 10 to 12 grams a day intravenously and "feeling great." That figure describes anecdotal IV use under presumed medical supervision, distinct from the 10 mg/kg oral case-report dose above; see Side/Adverse effects for the dose-limiting neuropathy seen in formal trials.

Function/Mechanism of Action

Many cancer cells rely on glycolysis and lactate production even when oxygen is available (the Warburg effect), sustained partly through PDK-mediated suppression of PDH. DCA blocks that suppression, restoring glucose flux into the mitochondrial Krebs cycle.

Fructose, alpha-lipoic acid, and vitamin B1 (thiamine) act on the same pathway rather than opposing it: alpha-lipoic acid and B1 are cofactors for the pyruvate dehydrogenase complex itself, and fructose feeding in rats was shown to inhibit hepatic PDH kinase and raise the active fraction of PDH by 44% relative to glucose feeding, the same direction of effect as DCA rather than the opposite.

Medical uses/Effects

A case report describes a 58-year-old man with medullary thyroid carcinoma who relapsed with widespread tumors in October 2008 after a prior 7-year remission (achieved with an older chemotherapy drug, dacarbazine/DTIC) and after exhausting other chemotherapy options. His calcitonin tumor marker, initially 38,611 pg/mL (normal is under 20 pg/mL), fell to 2,000 pg/mL within about 4 months of starting DCA (10 mg/kg), and a May 2009 PET scan showed marked reduction across tumor sites; remission was maintained on continued DCA through the report's published follow-up.

Diisopropylamine dichloroacetate (DADA), a DCA derivative marketed in Japan for chronic liver conditions under the brand LiverAll, showed greater antitumor efficacy than DCA itself in a mouse breast-tumor model.

Side/Adverse effects

Human clinical trials of DCA have shown limited efficacy against solid tumors and a dose-limiting peripheral neuropathy, the main barrier to sustained higher dosing. Medullary thyroid carcinoma is a distinct tumor type from more common cancers, so a strong single-case response may not generalize; the case above is a call for further study rather than established treatment.