The Many Benefits of Curcumin
Curcumin is one of the most popular supplements used in the integrative approach to managing cancer. It is derived from turmeric root and the active component is diferuloylmethane. To obtain the desired effects, a large amount of dietary intake of turmeric root is required so it is usually supplemented in capsule and concentrated form. It is a potent antioxidant and also has many anti-cancer actions along with its natural capacity for detoxification. It can either be used alongside an integrative cancer protocol or used in the prevention setting.
Bioavailability
Curcumin absorbs very poorly unless it is combined with a selection of other micronutrients including bromelain and piperine or if it is administered or ingested in the phytosomal forms. The phytosomal form is now commercially available in supplements and is the form to pursue if desired. It also works synergistically with other supplements including EGCG, grapeseed extract, quercetin, boswelia, bromelain and ginger.
It is also available in intravenous form where its bioavailability and action is enhanced. This requires very close supervision and infusion in a center that is both qualified to administer and has experience in doing so. Seek a qualified practitioner for guidance and a qualified center for administration.
Mechanism of Action
Its endless list of actions in cancer is summarised below and is derived from the reference book; Naturopathic Oncology written by Dr Neil McKinney which is available here.
Curcumin has potent antioxidant effects and is used widely in the setting of detoxification. It mops up toxins such as superoxide, hydroxyl radicals and peroxynitrite. It is also a very effective anti-inflammatory working through decreasing both eicosanoids such as 5-Hydroxyeicosatetraenoic acid (5-HETE, a potent metabolite of arachidonic acid which plays a large role in many inflammatory diseases and carcinogenesis) and prostaglandin E2 (PGE-2) as well as other inflammatory factors including cyclooxygenase 2 (COX-2) and nuclear factor kappa B (NFkB) that are all responsible for significant pro-inflammatory actions.
It also has potent effects on the immune system including simulating the reticulo-endothelial immune system, activating phagocytosis and reducing interleukin-6 (IL-6).
It has preventative actions in cancer due to its epigenetic, anti-inflammatory, immune stimulating and DNA repair mechanisms. This includes protecting DNA damage from lipid peroxidation and inducing heat shock proteins to protect cells from stress. It also plays a role in blocking or inhibiting many oncogenes including c-jun, c-fos, c-myc, NIK, MAPKs, ERK, P13K, Akt, JNK, ikB kinase, CDKs, iNOS and other factors and receptors involved in tumour progression including TNF, MMP-9, AP-1, EGR-1, STAT 1 & 3, beta-catenin, HER2, Bcl-2, Bcl-SL, ICAM-1, TF and cyclin D1. It also inhibits mammalian target of rapamycin (mTOR, responsible in cell cycle signalling and progression of cell proliferation), protein kinase C (PKC), EGFR tyrosine kinase and TYK2, all of which are responsible for stimulating cancer cell proliferation and metastasis and inhibiting cancer cell apoptosis.
Its other direct anti-cancer benefits include inhibiting angiogenesis by blocking vascular endothelial growth factor receptor (VEGFR) and binding aminopeptidase N (APN). It is also thought to inhibit cancer stem cells and block cell cycle progression at the G2/S phase transition. It induces apoptosis in cancer cells via the ubiquinone-proteasome pathway and by increasing the protein expression of Bax and Bcl-xs, decreasing Bcl-2 and Bcl-xL, releasing apoptogenic cytochrome c and augmenting the activity of caspase-9 and caspase-3.
Clinically, it has been shown to slow tumour growth, reduce pain, improve quality of life, inhibit the number and volume of tumours through mitigation of pro-inflammatory molecules that propagate cancer spread and inhibit cancer spread through the blockade of metalloproteinases and APN responsible for the invasiveness of cancer.
Special Considerations
As always, although the beneficial effects are numerous, there are a handful of settings in which curcumin is contraindicated and is why one should always be working with a practitioner qualified to oversee and guide its use. Curcumin is not to be given in the setting of biliary duct obstruction or jaundice. It should not be used in the setting of anaemia as it can bind iron and worsen the situation. It is also a mild blood thinner and should not be used in the setting of low platelets, bleeding risk or pre-operatively around surgery. Interestingly, it is considered carcinogenic in those who continue smoking tobacco and should not be used in current smokers.
References
Naturopathic Oncology: An Encyclopedic Guide for Patients & Physicians 4th ed. Dr Neil McKinney. Liaison Press Victoria Canada.
Zendehdel E, Abdollahi E, Momtazi-Borojeni AA, Korani M, Alavizadeh SH, Sahebkar A. The molecular mechanisms of curcumin's inhibitory effects on cancer stem cells. J Cell Biochem. 2019 Apr;120(4):4739-4747. doi: 10.1002/jcb.27757. Epub 2018 Sep 30. PMID: 30269360.
Zang S, Liu T, Shi J, Qiao L. Curcumin: a promising agent targeting cancer stem cells. Anticancer Agents Med Chem. 2014;14(6):787-92. doi: 10.2174/1871520614666140521114735. PMID: 24851881.
Naujokat C, McKee DL. The "Big Five" Phytochemicals Targeting Cancer Stem Cells: Curcumin, EGCG, Sulforaphane, Resveratrol and Genistein. Curr Med Chem. 2021;28(22):4321-4342. doi: 10.2174/0929867327666200228110738. PMID: 32107991.
Giordano A, Tommonaro G. Curcumin and Cancer. Nutrients. 2019 Oct 5;11(10):2376. doi: 10.3390/nu11102376. PMID: 31590362; PMCID: PMC6835707.
Ming T, Tao Q, Tang S, Zhao H, Yang H, Liu M, Ren S, Xu H. Curcumin: An epigenetic regulator and its application in cancer. Biomed Pharmacother. 2022 Dec;156:113956. doi: 10.1016/j.biopha.2Feng T, Wei Y, Lee RJ, Zhao L.
Liposomal curcumin and its application in cancer. Int J Nanomedicine. 2017 Aug 21;12:6027-6044. doi: 10.2147/IJN.S132434. PMID: 28860764; PMCID: PMC5573051.022.113956. Epub 2022 Nov 2. PMID: 36411666.
