Turmeric / Curcumin
Brief description
Curcumin comes from the ginger family and is best known as turmeric – a spice popular in Asian cooking.
It is a polyphenol and has potent antioxidant and anti-inflammatory effects(1).
Evidence base
Blood pressure (BP): A systematic review (SR) and meta-analysis of 35 randomised trials (RCTs) found supplementation of turmeric significantly reduced systolic and diastolic BP, suggesting it could be used as an adjunctive in blood pressure therapy(2). Other earlier trials appeared to reinforce these findings but only for diastolic BP(3, 4).
Oxidative stress: Multiple systematic reviews suggest turmeric supplementation reduces markers of oxidative stress as well as inflammatory cytokines(5, 6).
Diabetes: A SR of 59 RCTs found supplementation significantly improves fasting blood sugar (FBG), fasting insulin levels, HbA1c, and measures of insulin resistance (HOMA-IR)(7). In those with pre-existing diabetes, 9 RCTs concluded supplementation with turmeric was able to improve triglycerides, total cholesterol, LDL-C and HDL-C, plus improve FBG and HbA1c(8).
Cholesterol: A SR of 64 RCTs found supplementation was able to reduce total cholesterol, triglycerides, LDL-C, and HDL-C. However, it was unable to alter Apo-A or Apo-B levels. These studies were graded as ‘Low’ or ‘very low’ in certainty of evidence and so should be interpreted with caution(9).
Body weight: Findings from 60 RCTs demonstrated supplementation was able to significantly reduce body weight, BMI, waist circumference and body fat %. Obesity-related adipokines were also significantly lower (adiponectin & leptin)(6). In patients with metabolic related diseases supplementation had a significant effect on body weight, BMI, as well as FBG, HbA1c, HOMA-IR, HDL-C and C-Reactive Protein(10).
Recommended serving & duration.
Oral ingestion of turmeric is poorly absorbed(11), ensure it is taken with piperine (black pepper) – this will increase its bioavailability. It may also increase risk of side effects(12).
Commonly Curcumin is combined with either piperine or a lipid e.g. BCM-95 or Meriva. Dosages vary in studies examining curcumin but generally:
With peperine, 500mg curcumin with 5-6.7mg of piperine three times per day (total 1.5g and 15-20mg of piperine).
With BCM-95 (essential oils + curcumin), take 500mg twice per day.
With Meriva (curcumin and + soy lecithin) take 200-500mg twice daily.
Safety & tolerability
High dose (up to 8g/day) curcumin appears to be safe and well tolerated(13). However, users may experience the following side effects at higher doses: nausea & vomiting, diarrhoea, headache, rashes and or yellow stool(14).
Be aware not all Curcumin supplements have been tested.
If there is any doubt about whether curcumin supplements are safe for you to take, please consult with your healthcare provider.
References
Hewlings SJ, Kalman DS. Curcumin: A Review of Its Effects on Human Health. Foods. 2017;6(10).
Dehzad MJ, Ghalandari H, Askarpour M. Curcumin/turmeric supplementation could improve blood pressure and endothelial function: A grade-assessed systematic review and dose-response meta-analysis of randomized controlled trials. Clin Nutr ESPEN. 2024;59:194-207.
Karimi A, Moini Jazani A, Darzi M, Doost Azgomi RN, Vajdi M. Effects of curcumin on blood pressure: A systematic review and dose-response meta-analysis. Nutr Metab Cardiovasc Dis. 2023;33(11):2089-101.
Qiu L, Gao C, Wang H, Ren Y, Li J, Li M, et al. Effects of dietary polyphenol curcumin supplementation on metabolic, inflammatory, and oxidative stress indices in patients with metabolic syndrome: a systematic review and meta-analysis of randomized controlled trials. Front Endocrinol (Lausanne). 2023;14:1216708.
Hosseini H, Ghavidel F, Rajabian A, Homayouni-Tabrizi M, Majeed M, Sahebkar A. The Effects of Curcumin Plus Piperine Co-administration on Inflammation and Oxidative Stress: A Systematic Review and Meta-analysis of Randomized Controlled Trials. Curr Med Chem. 2024.
Dehzad MJ, Ghalandari H, Nouri M, Askarpour M. Effects of curcumin/turmeric supplementation on obesity indices and adipokines in adults: A grade-assessed systematic review and dose-response meta-analysis of randomized controlled trials. Phytother Res. 2023;37(4):1703-28.
Dehzad MJ, Ghalandari H, Nouri M, Askarpour M. Effects of curcumin/turmeric supplementation on glycemic indices in adults: A grade-assessed systematic review and dose-response meta-analysis of randomized controlled trials. Diabetes Metab Syndr. 2023;17(10):102855.
Tian J, Feng B, Tian Z. The Effect of Curcumin on Lipid Profile and Glycemic Status of Patients with Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis. Evid Based Complement Alternat Med. 2022;2022:8278744.
Dehzad MJ, Ghalandari H, Amini MR, Askarpour M. Effects of curcumin/turmeric supplementation on lipid profile: A GRADE-assessed systematic review and dose-response meta-analysis of randomized controlled trials. Complement Ther Med. 2023;75:102955.
Sun Z, Wei X, Bai J, Li W, Yang J, Deng Z, et al. The effects of curcumin on anthropometric and cardiometabolic parameters of patients with metabolic related diseases: a systematic review and dose-effect meta-analysis of randomized controlled trials. Crit Rev Food Sci Nutr. 2023;63(28):9282-98.
Anand P, Kunnumakkara AB, Newman RA, Aggarwal BB. Bioavailability of curcumin: problems and promises. Mol Pharm. 2007;4(6):807-18.
Han HK. The effects of black pepper on the intestinal absorption and hepatic metabolism of drugs. Expert Opin Drug Metab Toxicol. 2011;7(6):721-9.
Lao CD, Ruffin MTt, Normolle D, Heath DD, Murray SI, Bailey JM, et al. Dose escalation of a curcuminoid formulation. BMC Complement Altern Med. 2006;6:10.
Sharma RA, Euden SA, Platton SL, Cooke DN, Shafayat A, Hewitt HR, et al. Phase I clinical trial of oral curcumin: biomarkers of systemic activity and compliance. Clin Cancer Res. 2004;10(20):6847-54.
