Turmeric, Ashwagandha, Giloy and Wheatgrass — Are They Safe During Cancer Treatment?

Cooking with turmeric in normal amounts — a small amount in a curry or dal — is generally not what oncologists are concerned about. The concentration of curcumin in a teaspoon of turmeric cooked in food is far lower than in a supplement capsule or extract. What your team is asking you to pause is the concentrated supplement form. That said, mention it to your oncologist so they have the full picture, particularly on chemotherapy days or if you are eating large amounts regularly.

No. What matters is simpler: your liver controls how much of a drug stays in your blood at any given time, and many common herbs interfere with that control. The result is that your drug level goes higher or lower than your oncologist intended, without anyone knowing. You do not need to understand the biochemistry. What you need to do is tell your team about every supplement you are taking — in capsule, powder, or liquid extract form — before you continue.

This is one of the most understandable misunderstandings in oncology, and it is worth naming directly. A stimulated immune system is not the same as an immune system that targets cancer cells. Cancer cells have specific ways of hiding from the immune system, and the treatments that address that — checkpoint inhibitors — work by blocking those hiding mechanisms precisely. Adding a general immune stimulant on top of an immunotherapy drug is more likely to worsen immune-related side effects than to help the treatment work. Tell your team if you have been taking giloy.

Ashwagandha can influence hormone levels, including testosterone and thyroid hormones. In hormone-sensitive cancers — breast cancer, prostate cancer, and certain thyroid cancers — anything that affects hormone levels needs to be reviewed by your oncologist before you take it. If you are on hormone therapy such as tamoxifen, letrozole, or enzalutamide, an unplanned change in hormone signalling from a supplement is particularly important to avoid. Pause it and bring the question to your next appointment.

Chemotherapy lowers your white blood cell count — the part of your blood that fights bacterial infection. Unpasteurised juice, including wheatgrass and raw vegetable juices, can carry bacteria that a healthy immune system would handle without trouble but that a suppressed immune system cannot. The risk is not the wheatgrass itself; it is the bacterial load in a raw, unpasteurised product entering a body whose defences are reduced. If you are drinking any kind of juice during treatment, ask your team whether it needs to be pasteurised or avoided entirely.

Tell your oncologist at your next appointment, or call today if you are mid-cycle. Do not stop any of them suddenly on your own without asking first — your team will tell you the safest way to stop. The reason to tell them now is that they may want to review how your treatment has been going in light of what you have been taking. This is not a confrontation; it is information your team needs to look after you properly. Most oncologists have this conversation regularly and the aim is to help, not to judge.

The answer depends on which treatment you had and whether you remain on any long-term therapy. Some people finish active chemotherapy but continue on targeted therapy or hormone therapy for months or years — in that case, the interaction risk continues. Others who complete all treatment may be able to take certain supplements with guidance. Ask your oncologist specifically when it would be safe to restart and which supplements they would advise against long-term. Do not assume that finishing your main treatment means all supplements are now safe.

This is a real and common difficulty, and it comes from a place of love. One approach is to bring the conversation to your oncologist so they can explain the interaction risk directly to your family member — hearing it from a doctor often carries weight that you saying it yourself cannot. Another is to frame it around timing rather than belief: the doctor has asked me to pause these during treatment, and we can ask together when I can restart. You do not need to argue against the tradition. You just need the supplement paused while treatment is active.