What nutritional supplements are recommended for cancer patients undergoing chemotherapy and radiotherapy?

Nutritional Supplements for Cancer Patients in Chemotherapy and Radiotherapy

Intensive dietary counseling with oral nutritional supplements (ONS) as needed is the recommended approach for cancer patients undergoing chemotherapy and radiotherapy, rather than routine use of specific supplements. 1

Assessment and General Recommendations

Nutritional Assessment

• Nutritional risk should be assessed in all cancer patients before and during therapy 1
• Assessment should include:
  • Body mass index calculation
  • Food intake estimation
  • Presence and degree of weight loss
  • Muscle mass evaluation
  • Presence of anorexia and other nutritional impact symptoms
  • Performance status
  • Metabolic derangements

Basic Nutritional Support

• Nutritional intake should cover at least 30 kcal and 1.0-1.5 g protein per kg body weight 1
• Provide recommended daily allowance for all micronutrients 1
• Standard formulas are recommended for enteral nutrition 1
• Multivitamin-multimineral supplements in physiological doses (approximately equal to the RDA) are safe and useful when dietary patterns are restricted 1

Specific Recommendations by Treatment Type

During Radiotherapy

• For patients receiving radiotherapy to head/neck or gastrointestinal regions:
  • Individualized nutritional counseling by trained professionals is strongly recommended 1
  • ONS should be offered when dietary counseling alone is insufficient 1
  • Enteral tube feeding should be initiated if oral intake remains inadequate despite counseling and ONS 1
  • Weekly contact with dieticians during radiotherapy is recommended, especially for head and neck cancers 1

During Chemotherapy

• Routine enteral nutrition during chemotherapy is not recommended 1
• However, nutritional support should be provided if patients are malnourished or at risk of malnutrition 1
• Nutritional intervention should focus on increasing oral intake through dietary advice and symptom management 1

Specific Supplements

Fish Oil/Omega-3 Fatty Acids

• Evidence regarding fish oil supplementation is mixed 1
• Some studies show improvements in appetite, energy intake, body weight, and lean body mass in patients undergoing chemotherapy 1
• Long-chain N-3 fatty acids at doses up to 5 g/day are generally well-tolerated 1
• Caution: Patients receiving ibrutinib should avoid fish oil supplements due to risk of epistaxis 1

Antioxidants

• High-dose antioxidant supplements are discouraged during cancer treatment 1, 2, 3
• Antioxidants may potentially reduce the effectiveness of chemotherapy and radiotherapy 3
• The use of single high-dose micronutrients should be avoided 1

Vitamin D

• Vitamin D deficiency is common in cancer patients 1
• Supplementation to normalize levels may be beneficial, though evidence for improved outcomes is limited 1

Common Pitfalls and Cautions

• Avoid restrictive diets: Diets that restrict energy intake should be avoided in patients with or at risk of malnutrition 1
• Avoid unproven diets: Ketogenic diets and fasting have insufficient evidence of benefit and may increase risk of malnutrition 1
• Avoid high-dose supplements: High-dose micronutrients, particularly antioxidants, may interfere with cancer treatments 2, 3
• Avoid delay in nutritional intervention: If oral intake is inadequate despite counseling and ONS, tube feeding should be initiated promptly when weight loss reaches 5% from the initiation of treatment 1

Route of Nutrition Delivery

1. First line: Dietary counseling with food enrichment
2. Second line: Oral nutritional supplements
3. Third line: Enteral tube feeding if oral intake remains inadequate
4. Fourth line: Parenteral nutrition if enteral feeding is not tolerated or feasible 1

For patients receiving radiotherapy to the head/neck region, percutaneous gastrostomy (PEG) may be preferred over nasogastric tubes due to radiation-induced oral and esophageal mucositis 1.