Emerging evidence indicates that cancer is primarily a metabolic disease involving disturbances in energy production through respiration and fermentation. The genomic instability observed in tumor cells and all other recognized hallmarks of cancer are considered downstream epiphenomena of the initial disturbance of cellular energy metabolism. The disturbances in tumor cell energy metabolism can be linked to abnormalities in the structure and function of the mitochondria. When viewed as a mitochondrial metabolic disease, the evolutionary theory of Lamarck can better explain cancer progression than can the evolutionary theory of Darwin. Cancer growth and progression can be managed following a whole body transition from fermentable metabolites, primarily glucose and glutamine, to respiratory metabolites, primarily ketone bodies. As each individual is a unique metabolic entity, personalization of metabolic therapy as a broad-based cancer treatment strategy will require fine-tuning to match the therapy to an individual’s unique physiology.
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Metabolic health, medical education, and the case for bringing clinicians and coaches together
At the 2026 Unbreakable Health Retreat in Miami, Emily Kaplan hosted a panel with Bob Kaplan, Professor Thomas Seyfried, and Dr. Derek Lee on what it means to treat cancer as a metabolic disease. They discussed the glucose-ketone index (GKI), nutritional ketosis, and strategies aimed at restricting the fuels cancer cells depend on while considering how metabolic therapy can fit alongside standard cancer treatment.
The conversation also addressed the practical realities patients face when trying to pursue a metabolic approach within the conventional oncology system, including questions about nutrition, repurposed drugs, inherited cancer risk, and how to evaluate different treatment options. Seyfried and Lee connected these clinical questions back to mitochondrial dysfunction, fermentation, and the metabolic vulnerabilities that may offer additional targets for cancer treatment.
An abbreviated version of this discussion is available here, for free.
At the 2026 Unbreakable Health Retreat in Miami, Professor Thomas Seyfried presented the case that cancer is fundamentally a mitochondrial metabolic disease rather than primarily a genetic one. He contrasts the dominant somatic mutation theory with a metabolic model in which impaired mitochondrial respiration drives a shift toward fermentation, dysregulated cell growth, and the mutations commonly associated with cancer.
Citing the work of Otto Warburg and research from his lab at Boston College, Seyfried explains how cancer cells rely heavily on fermentable fuels—particularly glucose and glutamine—and why mitochondrial dysfunction sits upstream of many of the genetic abnormalities seen in tumors. He also discusses reactive oxygen species, altered cellular signaling, and the role of mitochondria in regulating cell growth and behavior.
The presentation then turns to the therapeutic implications of this model. Seyfried explains strategies aimed at placing tumor cells under metabolic stress by restricting the fuels they depend on, including ketogenic metabolic therapy and approaches targeting glucose and glutamine. For Seyfried, the therapeutic target follows directly from the biology: restrict the fuels cancer cells depend on, exploit their metabolic weaknesses, and treat mitochondrial dysfunction as the central feature of the disease.
An abbreviated version of this discussion is available here, for free.
MetFix and BSI Members can view the full 54-minute video.
