Herbs and supplements: talk to your team first
After a leukemia diagnosis, many people turn to herbal teas, vitamins and “immune-boosting” products to help themselves or a loved one. That wish is very understandable. But “natural” does not always mean “safe”: some herbs and supplements can weaken leukemia medicines, raise the risk of bleeding or harm the liver. This topic explains what to watch out for and how to talk to your team about it.
01Short answer
02Simple explanation
Supplements (vitamins, minerals, plant extracts, fish oil, probiotics and “immune” powders) are sold in many countries without being tested the way medicines are. Their contents and dose may differ from what the label says.
The liver breaks down medicines using special enzymes. Some herbs speed these enzymes up or slow them down. As a result, a leukemia medicine may work too weakly, or too strongly and cause more side effects.
Some supplements affect blood clotting. When platelets are already low, this can raise the risk of bleeding.
Plant products grow in soil and can carry germs and mould. During neutropenia this can become a source of infection.
This does not mean everything is forbidden. The aim is to talk openly with your team and make a safe choice together. They will not judge you; they will try to protect you.
03Scientific explanation
St John’s wort and imatinib: in a 2004 study in healthy volunteers, St John’s wort sped up the clearance of imatinib by 43% and lowered its total amount in the blood by about 30%. The authors advise people taking imatinib to avoid St John’s wort. According to NCCIH, St John’s wort can weaken many medicines, including some cancer medicines.
Antioxidants and chemotherapy: in a 2020 observational study (SWOG S0221, breast cancer), taking antioxidant supplements (vitamins A, C and E, carotenoids, coenzyme Q10) before and during chemotherapy was linked to a higher risk of recurrence; vitamin B12 and iron were also linked to worse outcomes, while multivitamins were not. This is not direct evidence for leukemia, but it is a reason for caution.
Alternative treatment: in US studies from 2018, patients who chose only alternative treatment instead of standard treatment had about a 2.5 times higher risk of death; people who used complementary methods more often refused standard treatment, which worsened survival. These studies were in solid tumours, but the lesson applies generally.
Regulation: according to the US FDA, dietary supplements are not approved for safety and effectiveness the way medicines are before they go on sale. According to NCCIH, turmeric is usually safe as a spice, but cases of liver injury have been reported with supplements, and interactions with medicines are possible.
04What happens in the body?
Why tell your team first?
Your hematologist and pharmacist know your medicines, your blood tests and your stage of treatment. The same supplement can be harmless for one person and dangerous for another. They can check for interactions, suggest a safe alternative and, if needed, watch for changes in your blood tests.
Interactions
St John’s wort, grapefruit and pomelo, and some plant extracts affect liver enzymes. This can change the level of medicines taken by mouth, such as imatinib, dasatinib, venetoclax and ibrutinib. Folic acid supplements can interfere with methotrexate; do not take them unless your doctor has prescribed them.
Bleeding, liver and infection
Ginkgo, high-dose fish oil, garlic capsules and vitamin E can raise the risk of bleeding. Some plant extracts strain the liver, and many leukemia medicines also pass through the liver. Dried herbs, propolis and unpasteurised products can be a source of germs during neutropenia.
Folk remedies and “miracle” products
Black seed oil, mumiyo, aloe juice, propolis, “immune-boosting” powders and “anti-cancer” products sold online have not been studied enough in leukemia. There is no guarantee of what is in them. Be especially careful with products that promise too much, such as “a cure without chemotherapy” or “no side effects”.
What may be safe?
Ordinary amounts of spices and herbs in food, and weak herbal teas if your team agrees. If a deficiency is found, vitamin D or other supplements prescribed by your doctor. Safe complementary approaches such as relaxation, breathing exercises, gentle movement, music and conversation can improve wellbeing.
How to talk to your team
Take a list, or the actual packages, of everything you take or want to take to your doctor: vitamins, teas, drops, creams. Ask: does this affect my medicines? Is it dangerous if my platelets are low? When could I take it? Talking openly is the best way to protect yourself.
05Four steps before taking a supplement
A few minutes of conversation can prevent serious problems.
06Some products and possible risks (examples)
| Product | Possible risk | Note |
|---|---|---|
| St John’s wort | May lower the level of some leukemia medicines | Not advised for people taking imatinib |
| Grapefruit, pomelo | May raise the level of some medicines | Check the leaflet for your medicine |
| High-dose antioxidants | May interfere with chemotherapy | Agree with your team |
| Ginkgo, fish oil, garlic capsules | May raise the risk of bleeding | Especially when platelets are low |
| Turmeric and other extracts | Cases of liver injury reported | Usually fine as a spice in food |
| Folic acid | May interfere with methotrexate | Only if your doctor prescribes it |
| Dried herbs, propolis | May carry germs and mould | Especially during neutropenia |
* This list is not complete and is general information. Only your hematology team and pharmacist can tell you whether a product is safe for you.
07Key terms
- Dietary supplement
- A product made of vitamins, minerals, plants or other substances; not tested like a medicine.
- Interaction
- One substance changing how a medicine works.
- Liver enzymes
- Proteins that break down medicines, such as CYP3A4.
- Antioxidant
- A substance that reduces oxidation in cells; it may interfere with some treatments.
- Complementary approach
- A method used alongside standard treatment.
- Alternative treatment
- A method used instead of standard treatment; dangerous.
- Pharmacist
- A specialist in medicines and their interactions.
- St John’s wort
- A plant that interacts with many medicines.
08Key points
- “Natural” does not always mean “safe”.
- Discuss every supplement with your team first.
- St John’s wort can weaken some leukemia medicines.
- Grapefruit changes the level of some medicines.
- Some supplements raise the risk of bleeding.
- High-dose antioxidants are not advised.
- Alternative treatment should not replace standard treatment.
- Bring all packages and your list to the doctor.
09Frequently asked questions
Can I drink herbal tea?
Many weak herbal teas cause no problems in ordinary amounts, but some interact with medicines, and dried herbs can carry germs. Tell your team which tea you drink and get their agreement.
Will vitamin C boost my immunity?
Vitamins do not reverse neutropenia caused by treatment. High-dose vitamin C and other antioxidants may interfere with some treatments. A balanced diet is usually enough.
Relatives sent me an “anti-cancer” remedy from abroad. What should I do?
Appreciate their care, but show the product to your hematologist before taking it. Untested products can interact with medicines or be contaminated.
Can I eat honey?
Pasteurised, packaged honey usually causes no problems. Some centres advise avoiding raw honey after a transplant or during deep neutropenia. Ask your team.
Can I take supplements after treatment?
Some medicines (for example targeted medicines) may continue for a long time after the main treatment ends. Keep discussing every new supplement with your team.
Will my doctor be annoyed by my questions about supplements?
No. A good team values openness. Supplements taken in secret are more dangerous, because unexpected changes in blood tests then have no clear explanation.
10Questions for your doctor
Take these questions to your appointment. The ones you save are collected on the “My questions” page and stay on this device only.
Could the herbs, vitamins or supplements I take affect my treatment?
Which herbal teas and supplements should I avoid completely?
Does grapefruit or similar fruit affect my medicines?
If I want to take a supplement, whom should I ask first?
12Sources
- National Center for Complementary and Integrative Health (NCCIH). Cancer and Complementary Health Approaches: What You Need To Know
- National Center for Complementary and Integrative Health (NCCIH). Using Dietary Supplements Wisely
- National Center for Complementary and Integrative Health (NCCIH). St. John’s Wort
- National Center for Complementary and Integrative Health (NCCIH). Turmeric
- National Cancer Institute (NCI). Complementary and Alternative Medicine (CAM)
- Memorial Sloan Kettering Cancer Center. About Herbs, Botanicals & Other Products
- American Cancer Society. Dietary Supplements: What Is Safe?
- U.S. Food and Drug Administration (FDA). Dietary Supplements
- U.S. Food and Drug Administration (FDA). Grapefruit Juice and Some Drugs Don’t Mix
- Clinical Pharmacology & Therapeutics, 2004. Effect of St John’s wort on imatinib mesylate pharmacokinetics
- Journal of Clinical Oncology, 2020. Dietary Supplement Use During Chemotherapy and Survival Outcomes of Patients With Breast Cancer Enrolled in a Cooperative Group Clinical Trial (SWOG S0221)
- Journal of the National Cancer Institute, 2018. Use of Alternative Medicine for Cancer and Its Impact on Survival
- JAMA Oncology, 2018. Complementary Medicine, Refusal of Conventional Cancer Therapy, and Survival Among Patients With Curable Cancers