Keto Diet and Cancer: Beneficial or Concerning?

The ketogenic diet, or keto diet, has gained popularity in recent years as a potential approach to weight loss and improved metabolic health. 

However, its impact on cancer prevention and treatment remains a subject of debate. This article examines the existing evidence surrounding the keto diet and its potential benefits or concerns regarding cancer.

Understanding Cancer and Metabolism

Cancer cells display distinct metabolic characteristics, autonomously altering their metabolic pathways to meet increased bioenergetic and biosynthetic demands, and mitigate oxidative stress, thus promoting their proliferation and survival​​. 

The ketogenic diet, characterised by low carbohydrate and high fat intake, instigates a metabolic state termed “ketosis,” where the body predominantly uses fat, rather than glucose, as its fuel source​​.

Although some studies have suggested a link between the ketogenic diet and slowed tumour growth, these findings are largely based on animal models, and few human studies have shown promise​​. While the ketogenic diet may hold potential for some cancer patients, it’s crucial to note that it could also have adverse effects. The role of dietary interventions like the keto diet in cancer treatment continues to be a topic of active research​​.

Theoretical Benefits of the Keto Diet in Cancer Prevention

By limiting the availability of carbohydrates, it may reduce the levels of circulating glucose, potentially depriving cancer cells of their main energy source. This is particularly relevant given that cancer cells are known to predominantly use aerobic glycolysis (a process also known as the Warburg effect) for their metabolism. 

As such, this dietary manipulation could potentially target an important metabolic pathway of cancer cells. The role of the ketogenic diet in influencing cancer treatment and prognosis extends beyond inhibiting glucose/insulin signalling, potentially also involving mechanisms related to oxidative stress, mitochondrial metabolism, and inflammation​​.

While there is emerging evidence supporting the potential benefits of the ketogenic diet in cancer management, the diet’s effectiveness must be personalised to the individual patient. More research is needed to validate these findings and understand the potential risks associated with this dietary intervention.

Research Findings on the Keto Diet and Cancer

Cancer cells undergo metabolic reprogramming to support growth and manage oxidative stress. Research focuses on understanding metastatic cell metabolism and utilizing genetic analysis to stratify patients, exploring dietary interventions with metabolism-targeting therapies. The keto diet restricts carbs, promoting fat as the primary fuel source, inducing ketosis.

Studies show potential in slowing tumour growth in mice and certain brain tumours, but effects vary by cancer type or treatment. Digestive issues may occur due to difficulties in breaking down proteins and fats. The diet’s effectiveness in cancer management may involve inhibiting glucose/insulin signalling, reducing oxidative stress, and alleviating inflammation. Personalization is crucial, and further investigation is necessary.

Considerations and Potential Concerns

The ketogenic diet has potential advantages for cancer patients, but it also poses challenges and risks. Studies have noted that the diet’s restrictive nature can lead to nutritional deficiencies, including inadequate fibre intake. This is due to its heavy reliance on high-fat, low-carb foods, which may exclude nutrient-rich, high-fibre options. Additionally, the long-term feasibility of adhering to the ketogenic diet has been questioned, as many people find it difficult to maintain over time.

In the context of cancer treatment, recent research has highlighted a potential risk associated with the ketogenic diet. Studies in rodents have shown that while the diet can slow tumor growth, it may also accelerate a wasting disorder called cachexia. Cachexia leads to significant loss of muscle and fat tissue, which could shorten survival. However, these studies suggest that administering corticosteroids alongside the ketogenic diet might prevent the onset of cachexia while still slowing tumour growth, emphasizing the need for further investigation in this area.

The optimal macronutrient composition and duration of the ketogenic diet for cancer prevention and treatment are still subjects of ongoing research. Different types of cancer may respond differently to the diet, causing variations in its benefits and risks among patients. Therefore, it is important for individuals considering the ketogenic diet in the context of cancer treatment to consult with healthcare providers. These professionals can evaluate individual health needs and monitor for potential complications.

The ketogenic diet holds promise as an adjunct therapy for some cancers, but its downsides and the need for further study should be acknowledged. Ongoing research aims to provide clearer guidelines for its use in cancer prevention and treatment as our understanding evolves.


  1. Blackburn, K. B. (2018, April 18). The keto diet and cancer: What patients should know. MD Anderson Cancer Center.–what-patients-should-know.h00-159223356.html
  2. C. (n.d.). Ketosis: Definition, Benefits & Side Effects. Cleveland Clinic. 
  3. Could ketogenic diet “starve” cancer? Emerging evidence – PubMed. (2022, January 1). PubMed. 
  4. Martínez-Reyes, I., & Chandel, N. S. (2021, July 16). Cancer metabolism: looking forward – Nature Reviews Cancer. Nature.
  5. Eenfeldt, MD, D. A., Scher, MD, D. B., & Tamber, MD, D. M. (2016, June 27). A Keto Diet for Beginners: The #1 Ketogenic Guide – Diet Doctor. Diet Doctor.
  6. Staff, D. F. (2018, July 16). The Keto Diet and Cancer: What You Should Know | Dana-Farber Cancer Institute. Dana-Farber Cancer Institute.

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