Is a keto diet safe and effective for a cancer survivor?

Ketogenic Diet for Cancer Survivors: Safety and Effectiveness

The ketogenic diet is not recommended for cancer survivors due to lack of clinical evidence for efficacy and potential risks of malnutrition. 1

Current Evidence and Guidelines

The American Cancer Society and European Society for Clinical Nutrition and Metabolism (ESPEN) strongly discourage dietary approaches that restrict energy intake in cancer patients or survivors who are at risk of malnutrition 1. Despite the popularity of ketogenic diets among some cancer patients, there is insufficient evidence supporting their use:

• No clinical trials have demonstrated a benefit of ketogenic diets in cancer patients 1
• A systematic review of 39 studies with 770 patients found no conclusive evidence for anti-tumor effects or improved overall survival with ketogenic diets 2
• Most studies on ketogenic diets in cancer have low quality, high risk of bias, and are highly heterogeneous 2

Recommended Nutritional Approach for Cancer Survivors

Instead of restrictive diets like the ketogenic diet, cancer survivors should follow these evidence-based guidelines:

1. Focus on a balanced diet:

   • Consume a variety of vegetables and fruits (at least 5 servings daily) 1
   • Choose whole grains rather than refined grain products 3
   • Limit processed meat and red meat consumption 3
   • Maintain adequate protein intake from low-saturated fat sources (fish, lean meat, skinless poultry, eggs, low-fat dairy, nuts, seeds, legumes) 3

2. Maintain healthy body weight:

   • Achieve and maintain a healthy weight throughout survivorship 3
   • If overweight or obese, limit high-calorie foods and beverages while increasing physical activity 3

3. Engage in regular physical activity:

   • Aim for at least 150 minutes of moderate-intensity activity per week 3
   • Include strength training exercises at least 2 days per week 3
   • Return to normal daily activities as soon as possible after diagnosis 3

Risks of Ketogenic Diet for Cancer Survivors

The ketogenic diet poses several potential risks for cancer survivors:

• May lead to insufficient energy intake and unintentional weight loss due to low palatability 1
• Can contribute to malnutrition, which is already a concern for many cancer survivors 1
• Poor adherence rates reported in most studies, making it difficult to maintain 2
• Majority of patients on ketogenic diets experience significant weight loss and mild to moderate side effects 2

Individualized Nutritional Support

Cancer survivors with specific nutritional challenges should:

• Seek referral to a registered dietitian, preferably one who is a certified specialist in oncology 3
• Undergo nutritional assessment that considers treatment goals while focusing on current nutritional status 3
• Receive counseling focused on managing symptoms and encouraging intake of protein and energy-rich foods when needed 1

Conclusion

While ketogenic diets are often promoted as beneficial for cancer patients and survivors, current scientific evidence does not support their use. The American Cancer Society and other major organizations recommend a balanced diet rich in fruits, vegetables, and whole grains, along with regular physical activity, as the best nutritional approach for cancer survivors.