Turmeric

What Is Turmeric?

Turmeric has been used as both a food and medicine for thousands of years. Its orange pigment is due to the curcumin content, which is also one of the primary active phytochemicals in the plant.

Turmeric is a staple in Indian and other Southeast Asian cooking, and is thought to provide adaptogenic and general health-promoting effects in these regions.

There has been a lot of study on turmeric in recent decades investigating its effects on cancer, cardiovascular disease, diabetes, inflammatory conditions, and as an antibacterial and antiviral. Turmeric has shown promise in all of these areas.

The major problem with turmeric is its low bioavailability. Cooking the root for long periods of time such as with curry, or soups can improve this bioavailability in the gut but is still far less than 50% bioavailable. This is an issue when trying to use turmeric for systemic conditions, and requires a large amount of the herb to have any effect whatsoever. Combining turmeric with other herbs like black pepper (the piperine content) has shown dramatic improvements in bioavailability.

What Is Turmeric Used For?

Turmeric is mainly used in cooking, and as an anti-inflammatory agent. The potency of turmeric is believed to be increased after cooking, which has been shown to have some merit due to the increased bioavailability after cooking for long periods of time.

Turmeric is a potent anti-inflammatory, especially in the digestive tract and is commonly used to treat inflammations throughout. It’s especially useful for chronic inflammatory conditions like IBS, endometriosis, interstitial cystitis, and other inflammatory (and often idiopathic) conditions. It’s also used as an adjunctive cancer therapy for its potent antioxidant and anti-inflammatory activities.

Traditional Uses

Western Herbal Medicine

Turmeric has been used as a spice and medicine for thousands of years. It was listed in an ancient Assyrian herbal from around 600 BCE as well as by Dioscorides ^{5Reference 5Bone K · 2013Principles and Practice of Phytotherapy}.

Ayurvedic Medicine

In India, turmeric is used as a stomachic, tonic, to purify the blood, improve digestion, treat fevers, skin conditions, and vomiting during pregnancy. Here, it’s also applied topically to treat conjunctivitis, skin infections, cancer, sprains, arthritis, hemorrhoids, reduce hair growth, promote wound healing, and treat eczema. ^{5Reference 5Bone K · 2013Principles and Practice of Phytotherapy}. Its main, longstanding use, especially in Ayurveda is for its potent anti-inflammatory actions ^{3Reference 3Ammon HP · 1991Pharmacology of Curcuma longa}.

Traditional Chinese Medicine

(Turmeric rhizome; Jiang Huang)

Taste: Pungent and Bitter ^{6Reference 6Hempen et al. · 2009A Materia Medica for Chinese Medicine: Plants, Minerals, and Animal Products. (Pg 536-539)}

Energy

Warm ^{6Reference 6Hempen et al. · 2009A Materia Medica for Chinese Medicine: Plants, Minerals, and Animal Products. (Pg 536-539)}

Channels

Spleen, stomach, liver ^{6Reference 6Hempen et al. · 2009A Materia Medica for Chinese Medicine: Plants, Minerals, and Animal Products. (Pg 536-539)}

Actions

Regulates and moves blood, regulates and moves Qi, Descends Qi, dispels wind-damp, removes blood stasis, relieves pain ^{6Reference 6Hempen et al. · 2009A Materia Medica for Chinese Medicine: Plants, Minerals, and Animal Products. (Pg 536-539)}.

Indications

Do NOT use during pregnancy. ^{6Reference 6Hempen et al. · 2009A Materia Medica for Chinese Medicine: Plants, Minerals, and Animal Products. (Pg 536-539)}.

Dose

3-10 g decocted 20 min ^{6Reference 6Hempen et al. · 2009A Materia Medica for Chinese Medicine: Plants, Minerals, and Animal Products. (Pg 536-539)}

Contraindications

All forms of deficiency, especially if signs of blood or Qi stagnation are not present ^{6Reference 6Hempen et al. · 2009A Materia Medica for Chinese Medicine: Plants, Minerals, and Animal Products. (Pg 536-539)}.

(Turmeric tuber; Yu Jin)

Taste

Pungent, bitter, aromatic ^{6Reference 6Hempen et al. · 2009A Materia Medica for Chinese Medicine: Plants, Minerals, and Animal Products. (Pg 536-539)}

Energy

Cold ^{6Reference 6Hempen et al. · 2009A Materia Medica for Chinese Medicine: Plants, Minerals, and Animal Products. (Pg 536-539)}

Channels

Heart, lung, liver ^{6Reference 6Hempen et al. · 2009A Materia Medica for Chinese Medicine: Plants, Minerals, and Animal Products. (Pg 536-539)}

Actions

Moves and regulates blood and Qi, removes blood and Qi stasis, cools heat, cools blood, drains damp-heat ^{6Reference 6Hempen et al. · 2009A Materia Medica for Chinese Medicine: Plants, Minerals, and Animal Products. (Pg 536-539)}.

Indications

Do NOT use during pregnancy ^{6Reference 6Hempen et al. · 2009A Materia Medica for Chinese Medicine: Plants, Minerals, and Animal Products. (Pg 536-539)}.

Dose

3-10 g decocted 20 min ^{6Reference 6Hempen et al. · 2009A Materia Medica for Chinese Medicine: Plants, Minerals, and Animal Products. (Pg 536-539)}

Contraindications

Yin deficiency after blood loss, lack of indication of blood or Qi stagnation ^{6Reference 6Hempen et al. · 2009A Materia Medica for Chinese Medicine: Plants, Minerals, and Animal Products. (Pg 536-539)}.

In traditional Chinese medicine, turmeric is used to stimulate the blood and Qi, offer analgesic properties, treat chest and abdominal pain and distention, jaundice, frozen shoulder, amenorrhoea due to blood stasis. The tuber is used similarly to the root but is used more in hot conditions. ^{5Reference 5Bone K · 2013Principles and Practice of Phytotherapy}.

Botanical Information

A member of the Zingiberaceae family, it’s closely related to ginger (Zingiber officinalis). The Zingiberaceae family contains 50 genera and 1600 species.

Turmeric can grow up to 1m high. The flowers are pale yellow in colour. The rhizome has 2 parts, a primary, egg shaped primary rhizome (referred to in Chinese medicine as the tuber), and cylindrical, branched secondary rhizomes growing from the primary rhizome. ^{5Reference 5Bone K · 2013Principles and Practice of Phytotherapy}.

Habitat, Ecology & Distribution

Much of the cultivation of turmeric is in India (especially the south central states), as well as China, Taiwan, Philippines, Java, Haiti, Jamaica, and Peru ^{4,7Reference 4Battaglia · 2003The complete guide to aromatherapy (2nd ed.)Reference 7Swahn · 1991The lore of spices: Their history and uses around the world}.

Harvesting, Collection & Preparation

Turmeric essential oil is produced via steam distillation from the dried rhizome. It’s yellow in color due to the curcuminoids (0.3%-5.4%). ^{4Reference 4Battaglia · 2003The complete guide to aromatherapy (2nd ed.)}.

Pharmacology & Medical Research

Anti-inflammatory

Curcumin is a dual inhibitor of arachidonic acid metabolism ^{5Reference 5Bone K · 2013Principles and Practice of Phytotherapy}, as well as TNF induced Nf-kB ^{8Reference 8Zambre AP et al. · 2006Novel curcumin analogs targeting TNF-induced NF-κB activation and proliferation in human leukemic KBM-5 cellsView study →}.

Antioxidant

Turmeric acts as an antioxidant by reducing lipid peroxidation and priming Nrf2/ARE ^{5Reference 5Bone K · 2013Principles and Practice of Phytotherapy}.

Cancer

Curcumin has been found effective against leukemia ^{8Reference 8Zambre AP et al. · 2006Novel curcumin analogs targeting TNF-induced NF-κB activation and proliferation in human leukemic KBM-5 cellsView study →}, prostate cancer ^{9Reference 9Lin L et al. · 2006Antitumor agents}, and various inflammatory cascades ^{5,10,11Reference 5Bone K · 2013Principles and Practice of PhytotherapyReference 10Weber WM et al. · 2005Anti-oxidant activities of curcumin and related enonesView study →Reference 11Chen IN et al. · 2008Antioxidant and Antimicrobial Activity of Zingiberaceae Plants in Taiwan}.

Phytochemistry

Turmeric’s activity centres on the yellow curcuminoids — curcumin (diferuloylmethane, the principal marker), demethoxycurcumin, and bisdemethoxycurcumin — which influence transcription factors, cytokines, growth factors and kinases and underpin most of the cancer and anti-inflammatory research ^{5Reference 5Bone K · 2013Principles and Practice of Phytotherapy}. The steam-distilled rhizome also yields an aromatic essential oil rich in the sesquiterpenes ar-turmerone, α-turmerone and α-zingiberene, used as the markers for oil and oleoresin quality. The essential oil further contains zingiberene, β-sesquiphellandrene, 1,8-cineole, α-phellandrene, sabinene and borneol ^{4,5Reference 4Battaglia · 2003The complete guide to aromatherapy (2nd ed.)Reference 5Bone K · 2013Principles and Practice of Phytotherapy}.

Synthetic glycosyl-curcuminoids have been created and are currently being explored for medicinal applications and efficacy ^{1,2,9Reference 1Saladini M et al. · 2009New synthetic glucosyl-curcuminoids, and their (1)H and (13)C NMR characterization, from Curcuma longa LView study →Reference 2Lin L et al. · 2006Antitumor agentsReference 9Lin L et al. · 2006Antitumor agents}.

Constituent Summary

Mixed units (see “Amount”): curcuminoids are given as a share of the dried rhizome, essential-oil sesquiterpenes as a share of the distilled oil. Both vary widely by cultivar and origin; standardised extracts are typically ~95% curcuminoids ^{13,14Reference 13Li et al. · 2011Chemical Composition and Product Quality Control of Turmeric (Curcuma longa L.)View study →Reference 14Setzer et al. · 2021Variation in the Chemical Composition of Five Varieties of Curcuma longa Rhizome Essential Oils Cultivated in North AlabamaView study →}.

Pharmacokinetics

Curcumin is poorly absorbed, and rapidly metabolized where it’s conjugated in the liver. It’s then excreted in the faeces. This means the availability of curcumin in the body is limited. ^{12Reference 12Ireson C et al. · 2001AnimalCharacterization of metabolites of the chemopreventive agent curcumin in human and rat hepatocytes and in the rat in vivo, and evaluation of their ability to inhibit phorbol ester-induced prostaglandin E2 production}.

Clinical Applications

The potent antioxidant and anti-inflammatory activities of turmeric make it useful for treating inflammation, especially in the digestive tract, as well as throughout the body. It has shown strong potential as an adjunctive treatment for cancer and cardiovascular disease, and can be used to lower cholesterol and triglyceride levels.

Cautions & Safety

Turmeric is considered to be very safe, even in high doses over a long period of time.

The LD50 of a petroleum ether extract taken orally is 12.2g/kg in rats. There has been a fair bit of study in the toxicity of turmeric and various extracts, all finding the same low toxicity both with high dose, and long-term tests. ^{5Reference 5Bone K · 2013Principles and Practice of Phytotherapy}.

References

1. Saladini M, Lazzari S, Pignedoli F, Rosa R, Spagnolo F, & Ferrari E. (2009). New synthetic glucosyl-curcuminoids, and their (1)H and (13)C NMR characterization, from Curcuma longa L. Plant Foods For Human Nutrition (Dordrecht, Netherlands), 64(3), 224-9. doi:10.1007/s11130-009-0122-3
2. Lin L, Shi Q, Nyarko AK, Bastow KF, Wu CC, Su CY, Shih CCY, Lee KH (2006) Antitumor agents. 250 des synth N curcumin analogues potential anti-prostate cancer agents. J Med Chem 49:3963–3972
3. Ammon HP, Wahl MA. Pharmacology of Curcuma longa. Planta Med 1991;57:1-7.
4. Battaglia, S. (2003). The complete guide to aromatherapy (2nd ed.). Brisbane, Australia: International Centre of Holistic Aromatherapy.
5. Bone K, Mills S. (2013). Principles and Practice of Phytotherapy. Elsevier health. China. (Pg. 900-922).
6. Hempen, C. H., & Fischer, T. (2009). A Materia Medica for Chinese Medicine: Plants, Minerals, and Animal Products. (Pg 536-539).
7. Swahn, J. O. (1991). The lore of spices: Their history and uses around the world. New York: Crescent Books.
8. Zambre AP, Kulkarni VM, Padhye S, Sandur SK, Aggarwal BB (2006) Novel curcumin analogs targeting TNF-induced NF-κB activation and proliferation in human leukemic KBM-5 cells. Bioorg Med Chem 14:7196–7204. doi:10.1016/j.bmc.2006.06.056
9. Lin L, Shi Q, Nyarko AK, Bastow KF, Wu CC, Su CY, Shih CCY, Lee KH (2006) Antitumor agents. 250 des synth N curcumin analogues potential anti-prostate cancer agents. J Med Chem 49:3963–3972
10. Weber WM, Hunsaker LA, Abcouwer SF, Decka LM, Van der Jagbt DL (2005) Anti-oxidant activities of curcumin and related enones. Bioorg Med Chem 13:3811–3820. doi:10.1016/j.bmc.2005.03. 035
11. Chen IN, Chang CC, Ng CC, Wang CY, Shyu YT, Chang TL (2008) Antioxidant and Antimicrobial Activity of Zingiberaceae Plants in Taiwan. Plant Food Hum Nutr 63:15–20
12. Ireson C, Orr S, Jones Dj, et al. Characterization of metabolites of the chemopreventive agent curcumin in human and rat hepatocytes and in the rat in vivo, and evaluation of their ability to inhibit phorbol ester-induced prostaglandin E2 production. Cancer Res 2001;61:1058-1064
13. Li, S., Yuan, W., Deng, G., Wang, P., Yang, P., & Aggarwal, B. B. (2011). Chemical Composition and Product Quality Control of Turmeric (Curcuma longa L.). Pharmaceutical Crops, 2, 28-54. doi:10.2174/2210290601102010028
14. Setzer, W. N., Duong, L., Poudel, A., & Mentreddy, S. R. (2021). Variation in the Chemical Composition of Five Varieties of Curcuma longa Rhizome Essential Oils Cultivated in North Alabama. Foods, 10(2), 212. doi:10.3390/foods10020212