All the turmeric studies I read described the spice (and its derivative, curcumin) as generally safe for consumption. So I was surprised to see the full list of possible side effects on WebMD.
The first precaution was easy to dismiss – I was not pregnant or breast-feeding, though turmeric is deemed “likely safe” as long as women didn’t exceed amounts commonly found in food. So a plate of curry is probably fine, but not medicinal amounts of of turmeric.
The second contraindication is for people with gallbladder problems. I haven’t had issues with gallstones or bile duct obstructions – should be ok on that one.
The precaution on diabetes didn’t apply to me either, but those with diabetes should be aware that curcumin could decrease blood sugar. I’d count that as a positive side effect, unless of course your blood sugar gets too low.
People with stomach problems like gastroesophageal reflux disease (GERD) are also advised to proceed with caution, since turmeric can cause stomach upset and thus make GERD symptoms worse.
Two precautions concerned me the most: bleeding problems and interactions with hormone-sensitive conditions.
1) I’m taking warfarin (Coumadin) to prevent blood clots that I’m at a higher risk for as a cancer patient. The Xeloda chemo regimen that I’m on already interacts with warfarin to increase my risk of bleeding. Turmeric can slow blood clotting, so adding it into the mix with my meds might be risky, especially if I needed emergency surgery. However, I do get weekly monitoring through a lab test that measures my INR (international normalized ratio) to ensure that my blood clots within a specific time range. I told my oncologist that I would be taking a turmeric supplement, and she adjusts my warfarin dose as needed based on the INR results.
2) WebMD warns that curcumin supplementat
ion could make hormone-sensitive conditions — including breast, uterine and ovarian cancer — worse. This was the scariest contraindication for me, since my breast cancer is estrogen receptor positive.
But it was also contrary to most of the research I’d been reading. One study from 2010 did find a weak estrogenic effect, but their research only looked at curcumin’s behavior in a petri dish. Three of the study’s authors (including the lead author) published another article that same year in which they state:
…in vitro studies, ex vivo and first clinical investigations confirm the anti-tumor effects of Curcumin, either as an isolated chemoprevention substance or in combination with chemotherapeutic agents as supportive measure reducing pharmaceutical resistance of tumor cells to certain chemotherapeutics.
Besides, authors of the recent “Curcumin in Treating Breast Cancer: A Review” reference that 2010 study (which found the estrogenic effect), but come to a different conclusion than WebMD. They suggest that curcumin’s estrogenic effect actually help with breast cancer treatment:
…curcumin, acting as a phytoestrogen, competitively inhibited endogenous estrogen, which also contributed to the suppression of breast cancer cell growth.
I decided that enough research supported turmeric’s effectiveness against all types of breast cancer to justify dismissing WebMD’s warning, at least for now.
A few friends brought up two more concerns.
One woman’s oncologist told her not to take turmeric since she has liver mets and turmeric is metabolized by the liver. I have liver mets too, but my oncologist ok’d the turmeric supplementation. I didn’t come across any studies showing that turmeric could harm the liver – on the contrary, a 2016 review article described a few studies in which curcumin inhibited tumor growth in rats and mice with liver cancer. Maybe the liver mets keep me from processing turmeric as well as I otherwise would; I can only hope that I’m getting at least some of the benefits.
Finally, I looked into a concern brought up by another friend that wasn’t specific to turmeric, but questioned whether it was a good idea to supplement with any anti-oxidants at all while on chemo. Turmeric falls into this category since it demonstrates antioxidant activity. I hadn’t heard that before, but found a good summary of the issue from the Oncology Nutrition practice group of the Academy of Nutrition and Dietetics. My takeaway is that there’s no strong scientific evidence either for or against taking antioxidants during chemo, and it can depend on individual circumstances. Having read the studies that showed turmeric or curcumin working synergistically with Xeloda and other cancer treatments, I reaffirmed my decision to supplement with turmeric.
All that remained was to choose the brand of supplement and the dose. I’ll cover that decision-making process in my next post. I also resolved to eat more iron-rich foods like sardines and liver, since WebMD warns that turmeric can interfere with iron absorption. Still working on that part…