Does ketosis help fight cancer?

Ketogenic Diets and Cancer Treatment

Ketogenic diets are not recommended for cancer treatment due to lack of clinical evidence for efficacy and potential risks of malnutrition in cancer patients. 1

Current Evidence on Ketogenic Diets in Cancer

The ketogenic diet (high-fat, very-low-carbohydrate with adequate protein) has been proposed as a potential metabolic therapy for cancer based on the theory that it might exploit cancer cells' altered glucose metabolism. However, the clinical evidence does not support its use:

• No clinical trials have demonstrated survival benefits of ketogenic diets in cancer patients 1
• A 2021 systematic review of 39 studies with 770 patients found no conclusive evidence for anti-tumor effects or improved overall survival 2
• The European Society for Clinical Nutrition and Metabolism (ESPEN) strongly discourages dietary provisions that restrict energy intake in patients with or at risk of malnutrition 1

Potential Risks of Ketogenic Diets for Cancer Patients

Ketogenic diets may actually be harmful for cancer patients for several reasons:

• They may lead to insufficient energy intake and weight loss due to low palatability 1
• They increase the risk of insufficient intake of energy, fat, protein, and micronutrients 1
• Most studies report significant weight loss and mild to moderate side effects 2
• Patient adherence to ketogenic diets was rather low in most studies 2

Evidence-Based Nutritional Recommendations for Cancer Patients

Instead of ketogenic diets, guidelines recommend:

1. Adequate nutrition: Cancer patients should receive nutritional intervention to increase oral intake if malnourished or at risk of malnutrition 3
2. Balanced energy intake: Total energy expenditure of cancer patients generally ranges between 25-30 kcal/kg/day 3
3. Proper nutritional assessment: Including evaluation of food intake, body weight, muscle and fat reserves, physical performance, and inflammatory status 3
4. Symptom management: Nutrition counseling to manage symptoms that affect intake (e.g., xerostomia, nausea, mucositis) 1
5. Plant-based foods: Consuming a variety of vegetables and fruits (at least 5 servings daily) for their synergistic effects of vitamins, minerals, and phytochemicals 3

Common Misconceptions About Diet and Cancer

• Many "anti-cancer diets" including ketogenic diets are based on anecdotal evidence rather than scientific reasoning 1
• Sugar intake has not been shown to directly increase risk or progression of cancer, though limiting sugar is recommended to prevent weight gain 3
• There are no diets known to reproducibly cure cancer or prevent cancer recurrence 1

Future Research Directions

While preclinical studies suggest potential benefits of ketogenic diets as adjuvant treatments combined with standard therapies 4, current clinical evidence is insufficient to recommend this approach:

• More molecular studies and uniformly controlled clinical trials are needed 5
• Future research should focus on important clinical endpoints rather than surrogate markers 4
• Studies should investigate specific cancer types and stages where ketogenic diets might be more beneficial 6

In conclusion, while research on ketogenic diets in cancer continues, the current evidence-based approach emphasizes adequate nutrition with a focus on vegetables, fruits, and sufficient energy intake rather than restrictive diets that may compromise nutritional status.