The following are a selection of frequently asked questions put together by the MD Anderson cancer Center (at the University of Texas). It's great to see research like this coming out on the properties of natural foods, spices etc.

Frequently Asked Questions on curcumin

What is curcumin?

Curcumin is a component of an Indian spice, turmeric. It is estimated that 100 grams of turmeric contains three to five grams curcumin. Curcumin gives a yellow color to turmeric, also present in curry powder. Chemically, curcumin is called diferuloylmethane. Curcumin is yellow-orange in color. Curcumin is used as a natural yellow coloring in mustard, cereals, cheese and butter. In some countries, it is used as a natural coloring agent in the textile industry.

When was curcumin isolated?

Curcumin was isolated from the spice turmeric, as one of the active principles, more than 100 years ago.

What does curcumin do?

The activity of curcumin has been demonstrated against cancer, cardiovascular diseases, type II diabetes, Crohn's disease, psoriasis, atopic dermatitis, arthritis, etc.

How does curcumin work?

Turmeric has been described in Ayurveda (an ancient Indian system of medicine that means "long life") as an agent that can suppress inflammation. An extensive research during last 50 years has revealed that the anti-inflammatory activity of turmeric is due to curcumin. Curcumin can inhibit both the activity and the synthesis of cyclooxygenase-2 (COX2) and 5-lipooxygenase (5-LOX), as well as other enzymes that have been implicated in inflammation. Curcumin has also been shown to work through numerous other mechanisms. More than 700 genes have been shown to be modulated by curcumin.

Does curcumin work against cancer?

Curcumin has been shown to prevent a large of number of cancers in animal studies. Laboratory data indicate that curcumin can inhibit tumor initiation, promotion, invasion, angiogenesis and metastasis.

Epidemiological evidence indicate that incidence of certain cancers is less in people who consume curcumin than in those who do not. Recent evidence indicates that, besides chemopreventive activity, curcumin may also be effective in the treatment of cancer.

How does curcumin work against cancer?

Numerous mechanisms have been described for the anticancer activity of curcumin. Inhibition of proliferation of tumor cells, induction of apoptosis (a mode of cell death), inhibition of transformation of cells from normal to tumor, inhibition of invasion and metastasis and suppression of inflammation have been linked with the anticancer activity of curcumin. Down-regulation of COX2, 5-LOX, adhesion molecules, inflammatory cytokines, chemokines, growth factor receptors, vascular endothelial growth factor (VEGF) and transcription factors by curcumin have been linked to its antitumor activity.

Does curcumin work against arthritis?

Arthritis is also a proinflammatory disease. All current drugs approved for arthritis have anti-inflammatory activity. Anti-TNF (tumor necrosis factor) therapy has been approved for this disease. Curcumin has been shown to both suppress the TNF production and block the action of TNF. curcumin, when applied topically, has been shown to have activity against arthritis.

Does curcumin work against Crohn's disease (inflammatory bowl disease)?

Crohn's disease is also a pro-inflammatory disease. All current drugs approved for this disease have anti-inflammatory activity. Anti-TNF therapy has been approved for this disease. Curcumin has been shown to both suppress the TNF production and the TNF action. Curcumin taken orally has been shown to have activity against Crohn's disease.

Does curcumin accelerate wound-healing?

There is numerous experimental data that suggest that curcumin can accelerate wound healing. This has led Johnson & Johnson to supply a curcumin-containing Band-Aid (sold in India).

Does curcumin work against psoriasis?

Psoriasis is another proinflammatory disease. Considerable evidence, both in animals and humans, indicates that curcumin is quite effective against psoriasis when applied topically to the skin.

Does curcumin work against Alzheimer's disease?

Because Alzheimer's disease is caused in part by amyloid-induced inflammation, curcumin has been shown to be effective against Alzheimer's. Clinical trials are in progress at UCLA with curcumin for Alzheimer's.

Are there any human clinical trials done with curcumin?

There have been at least 10 different clinical trials performed with curcumin in patients with different diseases. These are mostly pilot studies that are proof of concept type. More than 10 trials are now in progress in the United States and other countries.

Has there been any toxicity associated with curcumin?

According to one of the phase I studies, curcumin was found to be safe in human subjects even when consumed at up to eight grams per day for three months. In spite of this finding, it is recommended that one take a lower dose of 500 mg/day, increasing to a higher dose gradually, if needed. Look for signs of both potential toxicity and improvement by talking to your body and to your doctor.

Did the 10 clinical trials use pure forms of curcumin or was curcumin in the form of turmeric?

The trials used almost pure curcumin.

Was other dietary intake of curcumin monitored closely during each trial?

Most trials have not monitored dietary curcumin because only people of the Indian subcontinent routinely use curcumin in their diets. A few trials (Plummer, 2001, and Sharma, 2001) have asked patients not to eat foods containing curcumin.

What is the basis for the large doses?

It is typical in medicine to find out the maximum tolerated dose (MTD).

Is it plausible to explore the lowest dose that provides the maximal benefit?

Yes, in fact there is some evidence that curcumin is an antioxidant even at low doses. There is also evidence that curcumin taken on an empty stomach is more effective.

Do subjects experience dyspepsia, ulcers, dermatitis and other side effects when taking curcumin in the pure form or as a component of curry or turmeric?

A few people have experienced diarrhea or transient nausea, but no major toxicity has been detected.

Are there any interactions between curcumin and other herbs or drugs?

Yes! Many potential interactions are described in turmeric and Curcumin: A review by Natural Standard.

To avoid potential interactions, be sure to let your health care provider know if you use this or any other type of complementary therapy.

Where do I read more about curcumin?

• Shishodia S, Sethi G, Aggarwal BB. Curcumin: getting back to the roots. Ann N Y Acad Sci. 2005 Nov;1056:206-17.
• Garg AK, Buchholz TA, Aggarwal BB. Chemosensitization and radiosensitization of tumors by plant polyphenols. Antioxid Redox Signal. 2005 Nov-Dec;7(11-12):1630-47.
• Aggarwal BB, Shishodia S, Takada Y, Banerjee S, Newman RA, Bueso-Ramos CE, Price JE. Curcumin suppresses the paclitaxel-induced nuclear factor-kappaB pathway in breast cancer cells and inhibits lung metastasis of human breast cancer in nude mice. Clin cancer Res. 2005 Oct 15;11(20):7490-8.
• Aggarwal S, Ichikawa H, Takada Y, Sandur SK, Shishodia S, Aggarwal BB. Curcumin (diferuloylmethane) down-regulates expression of cell proliferation and antiapoptotic and metastatic gene products through suppression of IkappaBalpha kinase and Akt activation. Mol Pharmacol. 2006 Jan;69(1):195-206.
• Shishodia S, Amin HM, Lai R, Aggarwal BB. Curcumin (diferuloylmethane) inhibits constitutive NF-kappaB activation, induces G1/S arrest, suppresses proliferation, and induces apoptosis in mantle cell lymphoma. Biochem Pharmacol. 2005 Sep 1;70(5):700-13.
• Siwak DR, Shishodia S, Aggarwal BB, Kurzrock R Curcumin-induced antiproliferative and proapoptotic effects in melanoma cells are associated with suppression of IkappaB kinase and nuclear factor kappaB activity and are independent of the B-Raf/mitogen-activated/extracellular signal-regulated protein kinase pathway and the Akt pathway.Cancer. Aug 15;104(4):879-90.
• Yan C, Jamaluddin MS, Aggarwal B, Myers J, Boyd DD. Gene expression profiling identifies activating transcription factor 3 as a novel contributor to the proapoptotic effect of curcumin. Mol cancer Ther. 2005 Feb;4(2):233-41.
• Aggarwal BB, Shishodia Suppression of the Nuclear Factor-{kappa}B Activation Pathway by Spice-Derived Phytochemicals: Reasoning for Seasoning. Ann N Y Acad Sci. 2004 Dec;1030:434-41.
• Takada Y, Bhardwaj A, Potdar P, Aggarwal BB. Nonsteroidal anti-inflammatory agents differ in their ability to suppress NF-kappaB activation, inhibition of expression of cyclooxygenase-2 and cyclin D1, and abrogation of tumor cell proliferation. Oncogene. 2004 Dec 9;23(57):9247-58.
• Dorai T, Aggarwal BB. Role of chemopreventive agents in cancer therapy. Cancer Lett. 2004 Nov 25;215(2):129-40.
• Li L, Aggarwal BB, Shishodia S, Abbruzzese J, Kurzrock R. Nuclear factor-kappaB and IkappaB kinase are constitutively active in human pancreatic cells, and their down-regulation by curcumin (diferuloylmethane) is associated with the suppression of proliferation and the induction of apoptosis. cancer. 2004 Nov 15;101(10):2351-62.
• Aggarwal BB, Takada Y, Oommen OV. From chemoprevention to chemotherapy: common targets and common goals. Expert Opin Investig Drugs. 2004 Oct;13(10):1327-38.
• Aggarwal, BB, Kumar A, Bharti A. Therapeutic potential of curcumin derived from turmeric (Curcuma longa), Invited review for Herbal and Traditional Medicine: Molecular Aspects of health (ed by Lester Packer, Choon Nam Ong and Barry Halliwell); Marcel Dekker, New York; p781-812; 2004.
• Aggarwal BB, Kumer A, Aggarwal MS, Shishodia S. Curcumin derived from turmeric (Curcuma longa): A spice for all seasons, in phytochemicals in cancer Chemoprevention (ed by Debasis Bagchi, pH.D., and Harry G. Preuss, M.D.) CRC Press
• Aggarwal S, Takada Y, Singh S, Myers JN, Aggarwal BB. Inhibition of growth and survival of human head and neck squamous cell carcinoma cells by curcumin via modulation of nuclear factor-kappaB signaling. Int J cancer. 2004 Sep 20;111(5):679-92. Erratum in: Int J cancer. 2004 Dec 20;112(6):1086.
• Bharti AC, Takada Y, Aggarwal BB. Curcumin (diferuloylmethane) inhibits receptor activator of NF-kappa B ligand-induced NF-kappa B activation in osteoclast precursors and suppresses osteoclastogenesis. J Immunol. 2004 May 15;172(10):5940-7.
• Bharti AC, Shishodia S, Reuben JM, Weber D, Alexanian R, Raj-Vadhan S, Estrov Z, Talpaz M, Aggarwal BB. Nuclear factor-kappaB and STAT3 are constitutively active in CD138+ cells derived from multiple myeloma patients, and suppression of these transcription factors leads to apoptosis. blood. 2004 Apr 15;103(8):3175-84. Epub 2003
• Yan C, Wang H, Aggarwal B, Boyd DD. A novel homologous recombination system to study 92 kDa type IV collagenase transcription demonstrates that the NF-kappaB motif drives the transition from a repressed to an activated state of gene expression.FASEB J. 2004 Mar;18(3):540-1. Epub 2004 Jan 8.
• Bharti AC, Donato N, Aggarwal BB. Curcumin (diferuloylmethane) inhibits constitutive and IL-6-inducible STAT3 phosphorylation in human multiple myeloma cells.J Immunol. 2003 Oct 1;171(7):3863-71.
• Shishodia S, Potdar P, Gairola CG, Aggarwal BB. Curcumin (diferuloylmethane) down-regulates cigarette smoke-induced NF-kappaB activation through inhibition of IkappaBalpha kinase in human lung epithelial cells: correlation with suppression of COX-2, MMP-9 and cyclin D1.Carcinogenesis. 2003 Jul;24(7):1269-79. Epub 2003 May 9.
• Aggarwal BB, Kumar A, Bharti AC. Anticancer potential of curcumin: preclinical and clinical studies.Anticancer Res. 2003 Jan-Feb;23(1A):363-98. Review.
• Mukhopadhyay A, Banerjee S, Stafford LJ, Xia C, Liu M, Aggarwal BB. Curcumin-induced suppression of cell proliferation correlates with down-regulation of cyclin D1 expression and CDK4-mediated retinoblastoma protein phosphorylation.Oncogene. 2002 Dec 12;21(57):8852-61.
• Bharti AC, Donato N, Singh S, Aggarwal BB. Curcumin (diferuloylmethane) down-regulates the constitutive activation of nuclear factor-kappa B and IkappaBalpha kinase in human multiple myeloma cells, leading to suppression of proliferation and induction of apoptosis. blood. 2003 Feb 1;101(3):1053-62. Epub 2002 Sep 5.
• Anto RJ, Mukhopadhyay A, Denning K, Aggarwal BB. Curcumin (diferuloylmethane) induces apoptosis through activation of caspase-8, BID cleavage and cytochrome c release: its suppression by ectopic expression of Bcl-2 and Bcl-xl. Carcinogenesis. 2002 Jan;23(1):143-50.
• Mukhopadhyay A, Bueso-Ramos C, Chatterjee D, Pantazis P, Aggarwal BB. Curcumin downregulates cell survival mechanisms in human prostate cancer cell lines. Oncogene. 2001 Nov 15;20(52):7597-609.
• Kumar A, Dhawan S, Hardegen NJ, Aggarwal BB. Curcumin (Diferuloylmethane) inhibition of tumor necrosis factor (TNF)-mediated adhesion of monocytes to endothelial cells by suppression of cell surface expression of adhesion molecules and of nuclear factor-kappaB activation. Biochem Pharmacol. 1998 Mar 15;55(6):775-83.
• Mehta K, Pantazis P, McQueen T, Aggarwal BB. Antiproliferative effect of curcumin (diferuloylmethane) against human breast tumor cell lines. Anticancer Drugs. 1997 Jun;8(5):470-81.
• Singh S, Aggarwal BB. Activation of transcription factor NF-kappa B is suppressed by curcumin (diferuloylmethane) [corrected] J Biol Chem. 1995 Oct 20;270(42):24995-5000. Erratum in: J Biol Chem 1995 Dec 15;270(50):30235.
• Reddy S, Aggarwal BB. Curcumin is a non-competitive and selective inhibitor of phosphorylase kinase. FEBS Lett. 1994 Mar 14;341(1):19-22.