For decades, the prevailing view in oncology has framed cancer as a genetic disease driven by DNA mutations—a perspective that has shaped billions of dollars in research and treatment strategies. However, Thomas Seyfried, a professor of biology with over 30 years of cancer research experience, challenges this dogma. His theory is that cancer is not primarily a genetic disease but a metabolic one, rooted in damaged mitochondria. By targeting the body’s cellular powerhouses the hope is to offer a better understanding how to prevent and treat the disease in a non-toxic way.
Seyfried’s core argument is that cancer originates from damaged mitochondria, not genetic mutations. He asserts that DNA damage, often cited as the cause of cancer, is merely a symptom of a deeper issue: mitochondrial dysfunction. When mitochondria—the organelles responsible for producing energy through oxidative phosphorylation—become impaired, cells revert to an ancient fermentation pathway, burning glucose and glutamine without oxygen. This metabolic shift, known as the Warburg Effect, leads to uncontrolled cell growth, a hallmark of cancer. Seyfried’s research demonstrates that cells with damaged DNA but healthy mitochondria do not develop cancer, while cells with healthy DNA but damaged mitochondria do, underscoring the pivotal role of mitochondria in cancer’s onset.
This theory builds on the work of Otto Warburg, who won the 1931 Nobel Prize in Medicine for observing that cancer cells ferment sugar even in the presence of oxygen. Warburg believed cancer was a metabolic disease, a view Seyfried revives and expands upon. Modern science largely ignored Warburg’s theory in favor of the somatic mutation theory, but Seyfried argues this was a mistake. He points to additional support from biologist Michael Levin, whose research suggests cancer is a disease of failed bioelectric signaling, further challenging the genetic model. Seyfried’s unified view is that all cancers, regardless of the organ they affect (e.g., breast, lung, brain), are fundamentally one disease caused by mitochondrial dysfunction. Current medical approaches, which treat tumors based on their location, are thus addressing symptoms rather than the root cause.
Why the Genetic Model Falls Short
Seyfried’s critique of the genetic model is sharp. He notes that despite billions spent on the “war on cancer,” the disease’s prevalence is rising: 1,676 people die daily from cancer in the U.S., and young, seemingly healthy individuals are being diagnosed more frequently than ever. Even inherited cancer genes like BRCA1, often cited as evidence for the genetic model, link back to mitochondrial dysfunction. These genes affect mitochondrial proteins in the electron transport chain, key to energy production, raising cancer risk but not directly causing it without mitochondrial impairment. Seyfried argues that the focus on genetic sequencing and mRNA cancer vaccines misses the point if cancer’s root lies in metabolism.
What Damages Mitochondria?
Seyfried identifies numerous factors that impair mitochondrial function, contributing to cancer risk. These include ultra-processed foods, high-carb diets at inappropriate times, insulin resistance, chronic inflammation, lack of exercise, poor sleep, chemical toxins, heavy metals, mold, EMFs (e.g., Wi-Fi, 5G), chronic stress, viruses (e.g., HPV, Hepatitis), and artificial blue light. These stressors disrupt the mitochondria’s ability to produce energy efficiently, setting the stage for metabolic dysfunction and, ultimately, cancer.
A Metabolic Approach to Cancer Management
Seyfried acknowledges that standard treatments like chemotherapy, radiation, immunotherapy, and surgery can save lives but that they often cause serious long-term damage. He advocates using metabolic therapy to weaken tumors first, making low-dose chemo or immunotherapy more effective. However, he strongly advises against brain radiation, as it releases glucose and glutamine, fueling brain tumors. Seyfried sees metabolic therapy as safer and more effective, yet it remains ignored because it lacks profit potential—fasting and ketosis, for instance, are not lucrative for the medical industry.
Seyfried’s therapeutic strategy targets cancer cells’ reliance on glucose and glutamine, which they use for fermentation due to their damaged mitochondria. His approach includes nutritional ketosis through a ketogenic diet or fasting that starves cancer cells, as they cannot efficiently use ketones or fat for fuel. To this he adds targeting glutamine, an amino acid cancer cells depend on. However, long-term elimination is not advised due to glutamine’s role in immune function, and then Hyperbaric Oxygen Therapy (HBOT). HBOT is a medical treatment that involves breathing 100% oxygen in a pressurized environment, typically at a pressure higher than sea level atmospheric pressure. The therapy is designed to increase the amount of oxygen dissolved in the blood, thereby enhancing oxygen delivery to tissues throughout the body. HBOT is used to treat a variety of medical conditions by promoting healing, reducing inflammation, and addressing issues related to hypoxia (low oxygen levels) or ischemia (reduced blood flow). Combined with the ketosis and glucose restriction HBOT floods tumors with oxygen, benefiting normal cells while stressing and killing cancer cells, which cannot handle the oxidative stress.
Unfortunately, the adoption of metabolic therapy faces significant hurdles. It is not part of standard care, lacks billing codes, and doctors risk losing their licenses if they deviate from guidelines. The medical system, Seyfried argues, prioritizes treatment over prevention, a disconnect evident in 2025 as genetic-focused initiatives continue to dominate funding.
Prevention Through Mitochondrial Health
It is Seyfried’s opinion that you don’t get cancer if your mitochondria are healthy. He emphasizes early prevention through lifestyle changes to protect mitochondria, including intermittent and water fasting, high-quality sleep, seasonal whole foods, eliminating seed oils and ultra-processed foods, limiting alcohol/drugs/smoking, daily sunlight exposure, grounding, blue light protection, exercise, cold exposure, sauna, meditation, finding purpose, dental hygiene, limiting EMFs, eating seafood 3-5 times a week, walking 7,500-10,000 steps, nasal breathing etc
There is such a need for a true open scientific debate to advance knowledge, comparing outcomes rather than relying on dogma.
Cancer as a Metabolic Disease: On the Origin, Management and Prevention of Cancer
