The undesirable effects of turmeric

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Turmeric (Curcuma longa) is a polyphenol derived from a plant of Indian origin of the same name. It is used as a spice and is recognizable by its pronounced yellow color, typical of curry, of which it is one of the ingredients (1).

In Asia, turmeric has been used in medicine for many centuries. It has anti-inflammatory, antioxidant, anti-cancer and anti-infectious properties. It would also exert a protective action vis-à-vis the heart and liver (1).

Turmeric is also available in many forms of dietary supplement. Its active substances consist of three types of curcumin (1).

The undesirable effects of turmeric:

It is contraindicated in patients who suffer from obstruction of the bile ducts (stones). Those with liver disease should consult their doctor before taking turmeric. It is also contraindicated in people who have developed signs of allergy to this plant. High dose turmeric is not recommended for stomach or duodenal ulcers as it may increase irritation.

Situations related to cancer treatments

Turmeric would slow the development of many types of cancer. Combined with radiation therapy and chemotherapy, turmeric would promote greater cell death, and reduce metastasis formation and treatment toxicity (including skin damage caused by radiation therapy during breast cancer) (1,2 11,13,15,16).

Two recent studies have also established a positive effect on the quality of life of patients with different types of cancer treated with radiotherapy and / or chemotherapy. It should be noted, however, that the turmeric supplement analyzed in these studies presents a very specific formulation, which allows a better assimilation by the body. (11,12)

Although these studies seem to indicate a positive effect of turmeric during radiotherapy and certain chemotherapies, it is advisable not to consume them the same day of treatment (see section “Possible negative effects on cancer treatments” below).

In addition, it is assumed that the treatment effect is improved in the specific case of metothrexate-based chemotherapies (Emthexate®, Ledertrexate®, Metoject®, Metothrexate®) (2,3). The same effect is found in the treatment of advanced breast cancers with docetaxel-based chemotherapy (Docetaxel®, Taxotere®, Tevadocel®) (3,4), as well as pancreatic cancer (4) with chemotherapies. based on gemcitabine. However, further studies are needed to confirm these data (4,5).

In 2011, a review48 analyzed the efficacy of turmeric (360 mg 2 to 3 times daily for 3 days) on inflammatory bowel diseases, in combination with standard treatments. It appears that this combination turmeric-standard treatment significantly reduces symptoms and markers of inflammation (eg C-reactive protein). However, the effects of turmeric alone are not known and the limited number of participants does not allow definitive conclusions to be drawn.

In addition, turmeric and curcumin have given encouraging results for the treatment of postoperative edema90 and certain inflammations of the eye. Source

Possible negative effects on cancer treatments

It is best not to use turmeric in combination with certain chemotherapies, which it would reduce the action. This would be the case for cyclophosphamide (Endoxan®) (3,6) and, although further studies are needed to verify it, also for epipodophyllotoxins (Celltop®, Eposin®, Vepesid.® ..) (3,14 ) as well as for camptothecin-based breast cancer treatments (Campto®, Irinosin®, Irinotecan® …) (3) and Doxorubicine® (6).

Because of its antioxidant effect, turmeric may reduce the action of some conventional treatments based on an oxidative effect. This is the case with radiotherapy, cyclophosphamides, dacarbazine, platinum analogues, anthracyclines and some antitumor antibiotics such as bleomycin and mitomycin (2,8,9).

General side effects

Turmeric is not recommended for people with gallbladder problems (11) and heartburn (7). It can indeed aggravate these affections (7)

Since turmeric has an anticoagulant effect, it is advisable to stop all consumption 2 weeks before surgery (7).

Overdose of turmeric

The side effects of turmeric are dry mouth, flatulence and heartburn (at high doses). Some people with allergies may have intense reactions. Overdose results in nausea and vomiting.

Interactions with other medicines and dietary supplements

Turmeric can have an anticoagulant effect and lower blood sugar levels. If you follow a “classic” treatment that has the same effects, it is imperative to consult your doctor before using turmeric.

For the same reasons, caution should be exercised when simultaneous consumption of turmeric and other food supplements lowering blood sugar (garlic, aloe vera, beta-glucans, milk thistle, co-enzyme Q10, ginger, ginkgo, ginseng, omega-3 or EPA / DHA fatty acids) or having an anticoagulant effect (garlic / quercetin, milk thistle, grape seed extract / resveratrol, ginger, ginkgo, ginseng, flaxseed, omega-3 or EPA / DHA fish fatty acids, vitamin E). Always tell your doctor about this type of combination (1,7).

Dosage for adults

Taking turmeric should be considered with caution when combined with certain treatments. This is the case of radiotherapy, platinum analogues, anthracyclines and some antitumor antibiotics such as bleomycin and mitomycin. If you are taking any of these treatments, avoid taking turmeric on the day (s) of the treatment and the two days before and after it (2,8,9).

Turmeric is contraindicated for treatment with cyclophosphamide (Endoxan) and doxorubicin (Adriblastina®, Caelyx®, Doxorubicin®, Myocet®) (3,6); as well as in case of treatment of breast cancer based, for example, camptothecins (Campto®, Irinosin®, Irinotecan® …) (3) and doxorubicin (Adriblastina®, Caelyx®, Doxorubicine®, Myocet®) ( 6).

Turmeric is not recommended during pregnancy (8).

In all other cases, 8 g per day is generally well tolerated (1,5,8). Combined use with black pepper and fat increases the availability of turmeric in the body. Larger doses, intolerance or prolonged intake may cause indigestion, diarrhea and nausea (10).


  • American Institute for Cancer Research.Dietary Options for Cancer Survivors.2002.
  • Vandebroek A. Dietary supplements. Symposium on non-conventional cancer treatments, Stichting tegen Kanker, 2011.
  • Bayet-Robert M. et al.Phase I dose escalation trial of docetaxel plus curcumin in patients with advanced and metastatic breast cancer. Cancer Biol. Ther. 2010;9:8–14.
  • Anticancer fund. Supplements during cancer therapy. 2011.
  • Bauvet F. Use of complementary and alternative medicines, especially dietary supplements and phytotherapies, by patients undergoing oncological treatment. Unconventional Treatments Symposium, Foundation Against Cancer, 2011.
  • Belcaro G. et al. A controlled study of a lecithinized delivery system of curcumin (Meriva®) to alleviate the adverse effects of cancer treatment. Phytother Res. 2014 Mar;28(3):444-50. Epub 2013 Jun 15. PubMed PMID: 23775598
  • Panahi Y. et al. Adjuvant therapy with bioavailability-boosted curcuminoids suppresses systemic inflammation and improves quality of life in patients with solid tumors: a randomized double-blind placebo-controlled trial. Phytother Res. 2014 Oct;28(10):1461-7. Epub 2014 Mar 19. PubMed PMID: 24648302.
  • Jagetia GC.Radioprotection and radiosensitization by curcumin. Adv Exp Med Biol. 2007;595:301-20. Review. PubMed PMID: 17569217.
  • Saleh EM et al. Antagonism between curcumin and the topoisomerase II inhibitor etoposide: a study of DNA damage, cell cycle regulation and death pathways. Cancer Biol Ther. 2012 Sep;13(11):1058-71.
  • Bordoloi D. et al.Multi-Targeted Agents in Cancer Cell Chemosensitization: What We Learnt from Curcumin Thus Far. Recent Pat Anticancer Drug Discov. 2016;11(1):67-97.
  • Ryan J.L. et al.Curcumin for radiation dermatitis: A randomized, double-blind, placebo-controlled clinical trial of thirty breast cancer patients. Radiat. Res. 2013;180:34–43.

Learn more? Not found what you were looking for?

Looking for even more detailed information? You have not found a particular supplement? You may find answers to your questions on the following sites:

  • Complementary and Alternative Medecine for Cancer (CAM-Cancer)
  • Anticancer Fund
  • MedlinePlus
  • National Center for Complementary and Alternative Medicine (NCCAM)
  • Office of Dietary Supplements (ODS)
  • University of Maryland Medical Center (UMMC)

This application was made by the Foundation against Cancer. It was developed under the supervision of Dr. An Vandebroek, medical oncologist at ZNA Antwerpen, and Dr. Fanny Bauvet, medical oncologist at St. Anne’s Hospital St. Remi in Brussels. The content of the various forms has also been validated by the Anticancer Fund.

The content of these sheets is purely informative, only for personal use and does not replace a medical consultation. The card can not be released in any way without mentioning the Foundation Against Cancer as a source.

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