Curcumin

Written by: 
Richard Thomas, medical writer

Curcumin is the main active ingredient in the spice turmeric, or Indian saffron, a powder made from the roots of a member of the ginger family of plants.

Best known for its use in curry powder, turmeric (botanical name Curcuma longa) is notable for its bright yellow-orange colour and strong aroma and is widely used throughout the world, particularly in Asia, in cooking and as a fabric dye and paint pigment.

It has also been used for centuries, especially in India, in the medicinal treatment of a wide range of ailments from digestive and skin problems, such as eczema and psoriasis, to the healing of wounds and the reduction of inflammationThe body’s response to injury..

Like its plant cousin garlic, turmeric has more recently acquired something of a global reputation among modern researchers as a 'wonder herb' because of its multifaceted potential for healing.

More than 2,600 scientific studies published since curcumin first came to the attention of medical researchers in 1937 suggest that it has potential anti-inflammatoryAny drug that suppresses inflammation, antioxidantA chemical that can neutralise damaging substances called oxygen free radicals., antimicrobial, antibacterial, antifungal, anticoagulantA medication that prevens blood from clotting, or which reduces the likelihood of the blood to clot. and anti-cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body. effects. [1] [2]

These are due to chemicals found in turmeric called 'curcuminoids'. Curcuminoids are the fatOne of the three main food constituents (with carbohydrate and protein), and the main form in which energy is stored in the body.-soluble chemicals that give turmeric its distinctive smell and colour. But they also have a potent effect on the human body and recent research is confirming curcumin's traditional herbal medicinal benefit for a wide range of conditions, from the mild to the life-threatening.

Curcumin also seems to combine well with the health-giving effects of other dietary sources. An antioxidantA chemical that can neutralise damaging substances called oxygen free radicals. chemical in red wine called resveratrol, for example, is believed to help curcumin to keep arteries clear and therefore maintain a healthy cardiovascular systemThe body system consisting of the heart and blood vessels.. [3] This synergistic combination also seems to inhibit colonThe large intestine. cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body. effectively, [4] as does the combination of curcumin with other dietary sources with anti-cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body. potential, such as green tea. [5]

When curcumin is used with polyunsaturated or essential fatty acids found in fish oils and with plant oils such as those in flaxseed, starflower (borage) and evening primrose it seems to enhance their anti-inflammatoryAny drug that suppresses inflammation and anti-oxidative effects. [6]

A few studies have commented on some adverse side-effects - for example, the possibility that curcumin may increase the anti-bloodA fluid that transports oxygen and other substances through the body, made up of blood cells suspended in a liquid.-clotting effects of drugs such as heparinA substance produced by the body, or given as medication, that reduces the likelihood of the blood to clot, coagulate. and reduce the effect of chemotherapyThe use of chemical substances to treat disease, particularly cancer. in patients being treated for breast cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body. [7] [8] - but the majority of researchers consider curcumin to present very few safety issues.

There is consequently great scientific interest in curcumin's potential to prevent and treat a range of serious conditions, from Alzheimer's disease to various cancers - especially those of the digestive system, such as colonThe large intestine. and pancreaticRelating to the pancreas. cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body..

When used as a medicine, curcumin is usually given in the form of capsules. Curcumin eaten as a normal part of a curry meal is only a fraction as effective as specially encapsulated supplements, because most of its benefit is destroyed by the body's gastric juices during the normal digestive process. However, packaging in capsules also reduces the effect of curcumin, so delivery by injection is now being developed in the hope of improving its take-up by the body.

Uses

Serious medical conditions for which curcumin has already been suggested to be of benefit include the following:

Alzheimer's disease. Some experts believe that frequent ingestion of curcumin may explain why rates of dementiaDecline in mental capacity, brain functioning and memory that affects day-to-day living. are generally lower in countries where curry is a staple part of the diet. For example, in parts of India the incidenceThe number of new episodes of a condition arising in a certain group of people over a specified period of time. of dementiaDecline in mental capacity, brain functioning and memory that affects day-to-day living. is less than one-tenth that of the UK. The early stages of Alzheimer's disease have been shown to respond well to curcumin therapy in laboratory tests, with the result that clinical trials using curcumin supplements for people with Alzheimer's disease are now under way in a number of test centres around the world. Curcumin has been found to stop and even reverse the degeneration of nerveBundle of fibres that carries information in the form of electrical impulses. cells, inflammationThe body’s response to injury. and oxidative damage in the brain that, coupled with the build-up of harmful chemical deposits called amyloid plaques, are believed to underlie the disease. [9] [10]

Inflammatory bowel disease (IBDAn abbreviation for inflammatory bowel disease, a group of inflammatory conditions of the intestine. The two major forms are Crohn’s disease and ulcerative colitis.). Curcumin has been shown in recent clinical trials to improve the serious condition of inflammatory bowel diseaseA group of inflammatory conditions of the intestine. The two major forms are Crohn’s disease and ulcerative colitis., which is increasing in incidenceThe number of new episodes of a condition arising in a certain group of people over a specified period of time. especially among young people and can sometimes lead to cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body. if untreated for a long period.  [11] [12]

Cardiovascular disease (heart disease). Curcumin's properties as an anti-inflammatoryAny drug that suppresses inflammation, antioxidantA chemical that can neutralise damaging substances called oxygen free radicals., anticoagulantA medication that prevens blood from clotting, or which reduces the likelihood of the blood to clot. and antithrombotic agent have been shown to have a wide range of possible benefits for cardiovascular disease, including potentially protecting against hardening of the arteries (atherosclerosisDisease leading to fatty deposits in the inner walls of the arteries, which reduce and may eventually obstruct blood flow.) and so helping to prevent heart attacks. It may also have effects in preventing  irregular heart beats. [13]

Cancer. Curcumin has been shown in laboratory experiments to have major potential in inhibiting cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body. cells in a wide range of cancers, including cancers of the throat, breast, colonThe large intestine., pancreas, prostate, and skin (melanoma), where it appears to act as a powerful stimulant to cancerousMalignant, a tumour that may invade surrounding tissues or spread to distant parts of the body. cells to kill themselves. [14-17]

Lung cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body. and chronic obstructive pulmonary diseaseEmphysema and bronchitis; often associated with smoking and air pollution. Abbreviated to COPD.. Curcumin has also been shown in animal experiments to inhibit both lung cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body. progression and chronic obstructive pulmonary diseaseEmphysema and bronchitis; often associated with smoking and air pollution. Abbreviated to COPD. (COPDChronic obstructive pulmonary disease. Emphysema and bronchitis; often associated with smoking and air pollution.), a linked inflammatory disease of the lung, by reducing inflammationThe body’s response to injury. and promoting the death of cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body. cells. [18]

Peptic ulcers. Curcumin has been shown to inhibit the growth of the bacterium Helicobacter pylori, now known to be a cause of peptic ulcers and implicated in the development of gastric and perhaps colonThe large intestine. cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body.. [19]

Other uses

Curcumin may also help in the following conditions, but clear proof of efficacy is awaiting further trials:

  • Arthritis
  • Cystic fibrosisThickening and scarring of tissues, for example, owing to inflammation or injury.
  • Depression
  • Diabetes
  • HIV/AIDS
  • Liver disease, including cirrhosis
  • Obesity
  • Psoriasis and eczema
  • Radiation burns from cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body. treatment
References: 
  1. Hatcher H, Planalp R, Cho J et al.  Curcumin: from ancient medicine to current clinical trials. Cell Mol Life Sci 2008; 65(11): 1631-1652.
  2. Strimpakos AS, Sharma RA. Curcumin: preventive and therapeutic properties in laboratory studies and clinical trials. Antioxid Redox Signal 2008; 10(3): 511-545.
  3. 'Alcohol, wine and cardiovascular disease.' American Heart Association. http://www.americanheart.org/presenter.jhtml?identifier=4422, accessed Feb.2, 2009.
  4. Majumdar AP, Banerjee S, Nautiyal J, et al. Curcumin synergizes with resveratrol to inhibit colonThe large intestine. cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body.. Nutr Cancer. 2009; 61(4): 544-553.
  5. Xu G, Ren G, Xu X, et al. Combination of curcumin and green tea catechins prevents dimethylhydrazine-induced colonThe large intestine. carcinogenesis. Food Chem Toxicol (online 25 Oct 2009).
  6. Saw CL, Huang Y, Kong AN. Synergistic anti-inflammatoryAny drug that suppresses inflammation effects of low doses of curcumin in combination with polyunsaturated fatty acids: docosahexaenoic acid or eicosapentaenoic acidAn essential omega-3 fatty acid found in oily fish.. Biochem Pharmacol 2010; 79(3): 421-430.
  7. Sivagurunathan Somasundaram, Natalie A. Edmund, Dominic T. Moore et al. Dietary curcumin inhibits chemotherapyThe use of chemical substances to treat disease, particularly cancer.-induced apoptosisA natural process of programmed cell death, for example, when cells are old or damaged. in models of human breast cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body.. The Lineberger Comprehensive Cancer Center and the Department of Medicine, Division of Hematology/Oncology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599.
  8. Shah BH, Nawaz Z, Pertani SA, et al. Inhibitory effect of curcumin, a food spice from turmeric, on plateletStructure in the blood that helps the blood to clot.-activating factor- and arachidonic acid-mediated plateletStructure in the blood that helps the blood to clot. aggregation through inhibition of thromboxane formation and Ca2+ signaling. Biochem Pharmacol 1999; 58(7): 1167-1172.
  9. Shytle RD, Bickford PC, Rezai-Zadeh K et al. Optimized turmeric extracts have potent anti-amyloidogenic effects. Curr Alzheimer Res. 2009; 6(6): 564-571.
  10. 'Vitamin D, Curcumin May Help Clear Amyloid Plaques Found In Alzheimer's Disease.' ScienceDaily. http://www.sciencedaily.com/releases/2009/07/090715131558.htm, retrieved 29 November 2009.
  11. Majumdar AP, Banerjee S, Nautiyal J et al.  Curcumin synergizes with resveratrol to inhibit colonThe large intestine. cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body.. Nutr Cancer. 2009; 61(4): 544-553.
  12. Epstein J, Docena G, Macdonald TT et al. Curcumin suppresses p38 mitogen-activated protein kinase activation, reduces IL-1β and matrix metalloproteinase-3 and enhances IL-10 in the mucosa of children and adults with inflammatory bowel diseaseA group of inflammatory conditions of the intestine. The two major forms are Crohn’s disease and ulcerative colitis. . Br J Nutr. 2009;  2:1-9.
  13. Wongcharoen W, Phrommintikul A. The protective role of curcumin in cardiovascular diseases. Int J Cardiol. 2009;133(2): 145-151.
  14. O'Sullivan-Coyne G, O'Sullivan GC, O'Donovan TR et al. Curcumin induces apoptosisA natural process of programmed cell death, for example, when cells are old or damaged.-independent death in oesophageal cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body. cells. Br J Cancer 2009; 101(9): 1585-1595.
  15. Somers-Edgar TJ, Taurin S, Larsen L, et al. Mechanisms for the activity of heterocyclic cyclohexanone curcumin derivatives in estrogen receptor negative human breast cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body. cellThe basic unit of all living organisms. lines. Invest igational New Drugs 2009; (online 9 Oct 2009).
  16. Teiten MH, Gaascht F, Eifes S et al. Chemopreventive potential of curcumin in prostate cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body.. Genes & Nutr. 2009; (online 6 Oct 2009).
  17. Doris R. Siwak, Shishir Shishodia, Bharat B et al. Curcumin-induced antiproliferative and proapoptotic effects in melanoma cells are associated with suppression of IĸB kinase and nuclear factor B activity and are independent of the B-Raf/mitogen-activated/extracellular signal-regulated protein kinase pathway and the Akt pathway. Cancer 2005; 104: 879-890.
  18. Moghaddam SJ, Barta P, Mirabolfathinejad SG et al. Curcumin inhibits COPDChronic obstructive pulmonary disease. Emphysema and bronchitis; often associated with smoking and air pollution.-like airway inflammationThe body’s response to injury. and lung cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body. progression in mice. Carcinogenesis 2009; 30(11): 1949-1956.
  19. Mahady GB, Pendland SL, Yun G et al. Turmeric (Curcuma longa) and curcumin inhibit the growth of Helicobacter pylori, a group 1 carcinogen. Anticancer Res 2002; 22(6C): 4179-4181.