What are the benefits of mistletoe for medical conditions, including cancer?

Mistletoe Benefits in Medical Conditions

Mistletoe can be considered for improving quality of life in the short term for breast cancer patients, but there is limited evidence supporting its use for other medical conditions or for improving mortality outcomes. 1

Evidence for Mistletoe in Cancer Care

Quality of Life Benefits

• Mistletoe has received a Grade C recommendation for improving quality of life specifically in breast cancer patients undergoing chemotherapy 1
• Four randomized controlled trials (RCTs) conducted between 2004-2014 showed some evidence of quality of life improvement in breast cancer patients 1
• Different mistletoe preparations were tested in these trials:
  • PS76A2 (subcutaneous injection)
  • Helixor A (subcutaneous injection)
  • Iscador (subcutaneous injection)
  • Sample sizes ranged from 61 to 352 participants 1

Administration and Safety Considerations

• Mistletoe is typically administered as a subcutaneous injection in clinical trials 1
• Important safety considerations:
  • Subcutaneous mistletoe is not FDA-approved in the United States 1
  • There is evidence of reversible hepatotoxicity at high doses 1
  • Orally available mistletoe exists but ingestion of high doses of mistletoe berry or leaf can cause serious adverse reactions 1
  • Limited data exists on long-term effects, drug interactions, and toxicities 1

Recent Research

• A 2023 phase I trial of intravenous mistletoe extract (Helixor M) in advanced cancer patients found:
  • Manageable toxicities (primarily fatigue, nausea, and chills)
  • Disease control rate of 23.8% in heavily pretreated patients
  • Improved quality of life scores from baseline to week 4 2

Limitations of Current Evidence

Methodological Issues

• Studies on mistletoe have several limitations:
  • Variable formulations and preparations across studies 1
  • Inconsistent quality of research methodology 3, 4
  • Small sample sizes in many trials 1
  • Limited data on long-term outcomes 1

Conflicting Results

• A 2019 systematic review found that studies with better methodological quality showed less or no effects on quality of life 3
• The 2008 Cochrane review concluded that evidence supporting mistletoe's impact on survival or ability to fight cancer is weak 4

Clinical Application

When to Consider Mistletoe

• May be considered for breast cancer patients during chemotherapy to improve quality of life 1
• Should be administered by healthcare professionals where available 1
• Not recommended as a primary cancer treatment or with expectation of survival benefit

Monitoring and Precautions

• Monitor for potential side effects:
  • Injection site reactions
  • Fatigue
  • Nausea and chills 2
  • Potential hepatotoxicity at high doses 1
• Avoid in patients with known allergies to mistletoe components
• Should be used as complementary therapy alongside conventional cancer treatments, not as a replacement 5

Common Pitfalls

• Assuming mistletoe has proven anti-cancer effects beyond quality of life improvement
• Using non-standardized or unregulated preparations
• Self-administration without medical supervision
• Expecting survival benefits when evidence primarily supports quality of life improvements
• Using oral preparations which may have different safety profiles than the injectable forms studied in trials

While some evidence suggests mistletoe may improve quality of life in specific cancer populations, particularly breast cancer patients undergoing chemotherapy, the overall evidence remains limited and of variable quality. More high-quality research is needed before stronger recommendations can be made.