Curcumin, the primary active constituent found in turmeric, is responsible for the plant’s yellow color and for providing most of its medicinal qualities1,2—and like vitamin D, curcumin is one of those nutraceuticals for which research suggests a broad range of potential benefits. Likewise, turmeric has been used as a traditional remedy in Chinese and Indian ayurvedic medicine for more than 2,000 years,3 and the authors of a textbook on bioactive foods indicate that “the use of turmeric in Indian folk medicine is one of a veritable panacea, apparently efficacious for conditions that we would nowadays classify in the realm of infectious, inflammatory, metabolic and immunological diseases.”4 Also, like vitamin D, new research on curcumin is being published with great frequency. This article will review the human clinical research on curcumin that was published in 2015. Specifically, this includes research on dental health, psoriasis, thalassemia (an inherited blood disorder), PMS, exercise-related soreness/damage, diabetes, anxiety, depression and colitis.
Dental Health The Australian Dental Journal5 published a study comparing the anti-inflammatory effects of topically applied curcumin to those of chlorhexidine and chlorhexidine-metronidazole (germicidal gels) on experimental gingivitis in 60 subjects. Each gel was applied twice daily for 10 minutes for 29 days. By measuring inflammatory markers, results showed that the anti-inflammatory effects of topical curcumin were similar to chlorhexidine-metronidazole, but superior to chlorhexidine.
Since white spot lesions are common during orthodontic treatment, the journal Lasers in Medical Science,6 published a randomized study to evaluate the antimicrobial/anti-inflammatory effect of curcumin-photodynamic antimicrobial chemotherapy (curcumin) and chlorhexidine varnish on the plaque accumulation and gingival bleeding in 45 adolescents undergoing orthodontic treatment. The subjects were placed into three groups: chlorhexidine varnish 2 percent, placebo varnish and curcumin. After four weeks, both chlorhexidine and curcumin of treatment resulted in a significant reduction in gingival bleeding (P<0.05).
BioMed Research International7 published a 12-week, randomized, double-blind, placebo-controlled clinical trial that assessed the effectiveness of a topical steroid and bioavailable oral curcumin (Meriva, 2 g/day) or the steroid alone and in 63 patients with mild-to-moderate psoriasis. While results showed that both groups achieved a significant reduction in psoriasis severity, the reduction was greater in patients treated with both topical steroids and oral curcumin. Moreover, a serum marker of inflammation (IL-22) was significantly reduced in patients treated with oral curcumin.
The European Journal of Dermatology8 published another randomized, double-blind, placebo-controlled, clinical trial to investigate the safety and efficacy of oral curcumin together with real visible light phototherapy or simulated visible light phototherapy in 22 patients with moderate to severe plaque psoriasis. Results demonstrated that all patients included in the curcumin + real visible light phototherapy improved to the extent all “moderate” or “severe” plaques were eliminated (p<0.01). Lesions showed a response in 81 percent of the real visible light phototherapy patients, compared to only 30 percent of the simulated visible light phototherapy patients.
β-thalassemia, an inherited blood disorder that reduces the production of hemoglobin, has been reported to have various responses to antioxidant treatment. Hemoglobin E (HbE) is the most common form of β-thalassemia in Southeast. Asia Oxidative Medicine and Cellular Longevity9 published a study comparing an antioxidant cocktail of N-acetylcysteine, deferiprone (an iron chelator) and either curcumin or vitamin E in 60 patients with β-thalassemia/hemoglobin E. Patients were classified as responders if they showed improvements in markers in iron load and oxidative stress. Results showed that responders in both groups had significantly decreased iron load and oxidative stress, and significantly increased antioxidant capacity and hemoglobin concentration. The maximum increase (P < 0.01) in hemoglobin concentration was 11 percent at month four in curcumin group responders and 10 percent at month 10 in vitamin E group responders.
Complementary Therapies in Medicine10 published a double-blind, placebo-controlled study, which evaluated the effects of placebo or curcumin on the severity of PMS symptoms in 70 women. Participants received two capsules daily (100 mg/capsule) for seven days before menstruation and for three days after menstruation for three successive cycles and they recorded severity of the symptoms by daily record questionnaire. Results showed that after three consecutive cycles, treatment with curcumin, the total severity of PMS score had reduced by a significant 58.39 percent, while in the placebo, the reduction was only 13.63 percent.
Exercise Related Soreness/Damage
A study published by the European Journal of Applied Physiology investigated the effect of supplementation with curcumin (Theracurmin) or placebo on muscle damage after eccentric exercise in 14 untrained young men. Subjects performed 50 maximal isokinetic eccentric contractions of the elbow flexors with one arm, and the same exercise with the other arm four weeks later, and received 150 mg of curcumin before and 12 hours after each eccentric exercise bout in a randomized, crossover design. Results showed that subjects using curcumin recovered faster than those using the placebo (four days post-exercise: -31 ± 13 percent vs. -15 ± 15 percent), and peak serum creatine kinase (a measure of muscle damage) was 77.35 percent less compared to placebo (P < 0.05).
Similarly, the European Journal of Applied Physiology12 published a double-blind randomized-controlled crossover trial to examine the effects of oral curcumin supplementation (2.5 g twice daily) versus placebo on muscle damage, inflammation and delayed onset muscle soreness (DOMS) in 17, untrained exercising men. The constituents of the curcumin used were bisdemethoxycurcumin 29 mg, demethoxycurcumin 62.7 mg, and curcumin 964 with total curcuminoids 1,060 mg per tablet. At 24 and 48 hours post-exercise, curcumin supplementation resulted in moderate to large reductions in pain during single-leg squat, gluteal stretch, and squat jump, as well as small reductions in creatine kinase activity. A small increase in single-leg jump performance was associated with the pain reduction.
Experimental and Clinical Endocrinology & Diabetes13 published a study examining the potential effects of supplementation with 500 mg/day of curcumin on the progression of diabetic kidney disease for 15 to 30 days. The results were that curcumin supplementation markedly reduced the excretion of urinary micro-albumin (a marker of kidney damage) without any negative effect on blood glucose levels. Curcumin also reduced plasma MDA levels (a market of oxidative stress) and lipopolysaccharide (an inflammatory activator), while increasing IκB (an inhibitory protein on inflammatory signaling). In addition, curcumin helped upregulate several friendly gut bacteria important for maintaining gut barrier integrity and function.
Anxiety & Depression
The Chinese Journal of Integrative Medicine14 published a 30-day, double blind, crossover trial investigating the effects of curcumin (1 g/day) or placebo on the frequency of symptoms of anxiety and depression with 30 obese subjects. Severity of anxiety and depression was assessed at baseline and at weeks four, six and 10 of the trial using the Beck Anxiety Inventory and Beck Depression Inventory (scientifically validated assessment questionnaires). Results showed that anxiety scores were significantly reduced following curcumin therapy (P=0.03). However, curcumin supplementation did not exert any significant impact on depression.
Although curcumin failed to exhibit benefits for depression in the aforementioned study, an eight-week, randomized, double-blind, placebo-controlled study published in European Neuropsychophar-macology15 demonstrated different results. In this study, 50 patients with major depressive disorders were treated with curcumin (BCM-95, 500 mg, twice daily) or placebo. The Inventory of Depressive Symptomatology was used for assessing depressive symptoms, and an analysis of salivary, urinary and blood biomarkers were also collected. The results showed that, compared to placebo, changes in key biomarkers (e.g. leptin and endothelin-1) in curcumin-treated individuals was associated with greater reductions in depression scores after eight weeks of treatment.
Clinical Gastroenterology and Hepatology16 published a multicenter, randomized, placebo-controlled, double-blind study to investigate curcumin’s efficacy in inducing remission in 50 patients with active mild-to-moderate ulcerative colitis (UC), who were already being treated with the UC medication, mesalamine. Patients were randomly assigned to groups who were given curcumin capsules (3 g/day) or an identical placebo for one month. Results showed that 14 patients (53.8 percent) receiving curcumin achieved clinical remission at week four, compared with none of the patients receiving placebo (P = 0.01). Additionally, clinical response (defined as a reduction of ≥3 points in the Simple Clinical Colitis Activity Index) was achieved by 17 patients (65.3 percent) in the curcumin group vs. 3 patients (12.5 percent) in the placebo group (P < 0.001).
Curcumin is a well-researched nutraceutical with multiple applications to human health. The research published in 2015 is really just the tip of the iceberg where curcumin is concerned, and lends support to its value in dental health, psoriasis, thalassemia, PMS, exercise-related soreness/damage, diabetes, anxiety, depression and colitis.
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2 Curcuma longa (turmeric). Monograph. Altern Med Rev 2001;6 Suppl:S62-6.
3 Curcuma longa (turmeric). Monograph. Altern Med Rev 2001;6 Suppl:S62-6.
4 Togni S, Appendino G. Curcumin and Joint Health: From Traditional Knowledge to Clinical Validation. In: Watson RR, Preedy VR (eds.) Bioactive Food as Dietary Interventions for Arthritis and Related Inflammatory Diseases. San Diego: Academic Press; 2013:67-81.
5 Pulikkotil SJ, Nath S. Effects of curcumin on crevicular levels of IL-1β and CCL28 in experimental gingivitis. Aust Dent J. 2015 Sep;60(3):317-27.
6 Paschoal MA, Moura CM, Jeremias F, Souza JF, Bagnato VS, Giusti JS, Santos-Pinto L. Longitudinal effect of curcumin-photodynamic antimicrobial chemotherapy in adolescents during fixed orthodontic treatment: a single-blind randomized clinical trial study. Lasers Med Sci. 2015 Nov;30(8):2059-65.
7 Antiga E, Bonciolini V, Volpi W, Del Bianco E, Caproni M. Oral Curcumin (Meriva) Is Effective as an Adjuvant Treatment and Is Able to Reduce IL-22 Serum Levels in Patients with Psoriasis Vulgaris. Biomed Res Int. 2015;2015:283634.
8 Carrion-Gutierrez M, Ramirez-Bosca A, Navarro-Lopez V, Martinez-Andres A, Asín-Llorca M, Bernd A, Horga de la Parte JF. Effects of Curcuma extract and visible light on adults with plaque psoriasis. Eur J Dermatol. 2015 May-Jun;25(3):240-6.
9 Yanpanitch OU, Hatairaktham S, Charoensakdi R, Panichkul N, Fucharoen S, Srichairatanakool S, Siritanaratkul N, Kalpravidh RW. Treatment of β-Thalassemia/Hemoglobin E with Antioxidant Cocktails Results in Decreased Oxidative Stress, Increased Hemoglobin Concentration, and Improvement of the Hypercoagulable State. Oxid Med Cell Longev. 2015;2015:537954.
10 Khayat S, Fanaei H, Kheirkhah M, Moghadam ZB, Kasaeian A, Javadimehr M. Curcumin attenuates severity of premenstrual syndrome symptoms: A randomized, double-blind, placebo-controlled trial. Complement Ther Med. 2015 Jun;23(3):318-24.
11 Tanabe Y, Maeda S, Akazawa N, Zempo-Miyaki A, Choi Y, Ra SG, Imaizumi A, Otsuka Y, Nosaka K. Attenuation of indirect markers of eccentric exercise-induced muscle damage by curcumin. Eur J Appl Physiol. 2015 Sep;115(9):1949-57.
12 Nicol LM, Rowlands DS, Fazakerly R, Kellett J. Curcumin supplementation likely attenuates delayed onset muscle soreness (DOMS). Eur J Appl Physiol. 2015 Aug;115(8):1769-77.
13 Yang H, Xu W, Zhou Z, Liu J, Li X, Chen L, Weng J, Yu Z. Curcumin attenuates urinary excretion of albumin in type II diabetic patients with enhancing nuclear factor erythroid-derived 2-like 2 (Nrf2) system and repressing inflammatory signaling efficacies. Exp Clin Endocrinol Diabetes. 2015 Jun;123(6):360-7.
14 Esmaily H, Sahebkar A, Iranshahi M, Ganjali S, Mohammadi A, Ferns G, Ghayour-Mobarhan M. An investigation of the effects of curcumin on anxiety and depression in obese individuals: A randomized controlled trial. Chin J Integr Med. 2015 May;21(5):332-8.
15 Lopresti AL, Maes M, Meddens MJ, Maker GL, Arnoldussen E, Drummond PD. Curcumin and major depression: a randomised, double-blind, placebo-controlled trial investigating the potential of peripheral biomarkers to predict treatment response and antidepressant mechanisms of change. Eur Neuropsychopharmacol. 2015 Jan;25(1):38-50.
16 Lang A, Salomon N, Wu JC, et al. Curcumin in Combination With Mesalamine Induces Remission in Patients With Mild-to-Moderate Ulcerative Colitis in a Randomized Controlled Trial. Clin Gastroenterol Hepatol. 2015 Aug;13(8):1444-9.e1.
Gene Bruno, MS, MHS, the dean of academics for Huntington College of Health Sciences, is a nutritionist, herbalist, writer and educator. For more than 30 years he has educated and trained natural product retailers and health care professionals, has researched and formulated natural products for dozens of dietary supplement companies, and has written articles on nutrition, herbal medicine, nutraceuticals and integrative health issues for trade, consumer magazines and peer-reviewed publications. He can be reached at email@example.com.