Cancer as a Metabolic Disease

Based on the work of Thomas Seyfried, a professor of biology and researcher in cancer metabolism

Dr. Thomas Seyfried has spent decades studying cancer metabolism. He argues that cancer is fundamentally a metabolic disease, with impaired mitochondrial energy metabolism playing a central role in its development and growth.

His work builds on the Warburg effect—the observation that many cancer cells consume unusually large amounts of glucose and rely heavily on fermentation even when oxygen is available. Seyfried also emphasizes glutamine as an important fuel for many cancers.

Based on this theory, Seyfried proposes metabolic therapy aimed at restricting fuels that cancer cells depend upon while supporting healthy cells. His research has investigated ketogenic diets, fasting, glucose reduction, glutamine-targeting drugs, and other metabolic approaches.

Cancer metabolism is an important area of research, but Seyfried's therapeutic approach has not been established as a treatment for prostate cancer. Much of the evidence for his specific strategy comes from laboratory and animal studies, with human research still developing.

The Warburg Effect

Nearly a century ago, Nobel Prize-winning scientist Otto Warburg observed that cancer cells often process energy differently from normal cells.

Many cancer cells consume unusually large amounts of glucose and convert much of it to lactate through fermentation, even when oxygen is available. This is known as the Warburg effect.

This altered glucose metabolism is well established and helps explain why FDG-PET scans can detect many tumors: the radioactive tracer resembles glucose and accumulates in tissues with high glucose uptake.

Seyfried goes further, arguing that the Warburg effect reflects underlying mitochondrial dysfunction that plays a central role in causing and sustaining cancer. This interpretation is a key part of his theory.

Glucose, Glutamine and Cancer

Seyfried emphasizes two fuels used by many cancer cells: glucose and glutamine.

A ketogenic diet lowers blood glucose and insulin while raising ketones, which healthy cells can often use for energy. But Seyfried argues that reducing glucose alone is not enough because many cancer cells can also use glutamine.

This is why his approach is more complex than the popular phrase “sugar feeds cancer.” His strategy attempts to create metabolic stress in cancer cells by targeting more than one fuel pathway.

Seyfried's Metabolic Therapy

A central component of Seyfried's approach is therapeutic ketosis, usually achieved through a very-low-carbohydrate ketogenic diet, sometimes combined with fasting or calorie restriction.

He also studies ways to target glutamine metabolism. One experimental drug used in his research is DON (6-diazo-5-oxo-L-norleucine), a glutamine antagonist. Research involving DON remains largely preclinical.

Seyfried has also investigated combining metabolic therapy with approaches such as hyperbaric oxygen and conventional cancer treatments.

The goal is to alter the metabolic environment of the cancer while simultaneously targeting pathways that tumor cells may depend upon.

What Does the Research Show?

There is strong evidence that altered metabolism is a hallmark of cancer, and researchers are actively studying how cancer cells use glucose, glutamine, fats, and other fuels.

Laboratory and animal studies of ketogenic diets, calorie restriction, glutamine-targeting drugs, and other metabolic approaches have produced interesting results.

Human evidence is much more limited. Metabolic therapies have not been shown in large clinical trials to replace standard cancer treatment or improve survival across cancers.

For prostate cancer specifically, these approaches remain experimental and investigational.

What About Prostate Cancer?

Researchers have found connections between obesity, insulin resistance, metabolic health, and prostate cancer outcomes, and are investigating how prostate cancer cells use glucose, fats, and glutamine.

Researchers are also studying whether ketogenic diets and other metabolic interventions might eventually be useful alongside conventional treatment.

At present, there is not enough clinical evidence to recommend a ketogenic diet as a treatment for prostate cancer itself.

This distinction is important: maintaining good metabolic health may benefit overall health, while therapeutic ketosis as an anti-cancer treatment remains an area of research.

Learn More

Book

Thomas Seyfried — Cancer as a Metabolic Disease

Seyfried's major book explaining his theory of cancer metabolism.

Videos