Research Article

Efficacy and Safety of Curcumin Supplement on Improvement of Insulin Resistance in People with Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Table 2

The characteristics of the included studies.

StudyRegister IDCountrySample sizeInterventionRelevant outcomesDuration
Trial groupControl groupTrial groupControl group

Panahi et al. [1619]IRCT201505301165N4Iran5050Curcuminoids (C3 Complex®) 1000 mg + 10 mg piperinePlacebo + 10 mg piperineBMI, TG, TC, LDL-C, HDL-C, HOMA-IR, HbAlc, fasting blood glucose, fasting insulin, adiponectin adverse events12 weeks

Na et al. [20, 21]ISRCTN85826075China5050Curcuminoids 300 mg with no changes to patients’ previous drug medicationPlacebo with no changes to patients’ previous drug medicationTG, TC, LDL-C, HDL-C, HOMA-IR, HbAlc, fasting blood glucose12 weeks

Chuengsamarn et al. [11]NCT01052597Thailand107106Curcumin 1500 mg with no oral antidiabetes or insulin injectionPlacebo (starch) 1500 mg with no oral antidiabetes or insulin injectionBMI, TG, TC, LDL-C, HDL-C, HOMA-IR, HbAlc, fasting blood glucose, fasting insulin, adiponectin, adverse events24 weeks

Khajehdehi et al. [22]Iran2020Turmeric 1500 mg with no changes to patients’ previous drug medicationPlacebo with no changes to patients’ previous drug medicationTG, TC, LDL-C, HDL-C, HOMA-IR, HbAlc, fasting blood glucose, adverse events8 weeks

Asadi et al. [31, 32]IRCT20140413017254N5Iran4040Nanocurcumin 80 mg with no changes to patients’ previous hypoglycemic drugsPlacebo with no changes to patients’ previous hypoglycemic drugsBMI, HbAlc, fasting blood glucose, adverse events8 weeks

Thota et al. [33]ACTRN12615000559516Australia1516Curcumin 1000 mgPlacebo (2000 mg corn oil)HbAlc, TC, LDL-C, HDL-C, fasting blood glucose, adverse events12 weeks

Adibian et al. [34]NCT02529969Iran2123Curcumin 1500 mg with no changes to patients’ previous drug medicationPlacebo (rice flour) 1332 mg with no changes to patients’ previous drug medicationBMI, TG, TC, LDL-C, HDL-C, fasting blood glucose, fasting insulin, adiponectin10 weeks


StudyBMIMean age (years)Inclusion criteriaExclusion criteria
Trial groupControl groupTrial groupControl group

Panahi et al. [1619]26.53 ± 2.3227.33 ± 1.5843 ± 841 ± 7Diagnosis of T2DM based on fasting plasma glucose (FPG) ≥ 126 mg/dL, glycated hemoglobin (HbA1C) ≥ 6.5%, or the use of antidiabetic treatmentsPregnancy or breastfeeding, lack of possibility to give an informed consent, participation in a concomitant trial, presence of malignancies, chronic liver disease (alanine aminotransferase levels three times the upper limit of normal value range), renal failure (serum creatinine ≥ 2.0 mg/dL or being on dialysis), chronic inflammatory diseases such as rheumatoid arthritis and acute infections, endocrine diseases other than T2DM (e.g., hypothyroidism or hyperthyroidism), obsessive compulsive disorder, hyperglycemia due to secondary causes, receiving hormone therapy or other herbal medicines, hypersensitivity to the study medication, and lack of compliance with the study medication

Na et al. [20, 21]27.12 ± 2.2627.42 ± 3.0455.42 ± 6.4054.72 ± 8.34(1) Aged 18–65 years, both male and female
(2) Type 2 diabetes with fasting blood glucose greater than or equal to 7.0 mmol/L or postprandial blood glucose greater than or equal to 11.1 mmol/L
(3) Current optimal therapeutic regimens lasting for at least 6 months
(1) A history of type 1 diabetes, malignancies, thyroid, or any other endocrine diseases likely to interfere with the study
(2) Diabetic ketosis acidosis and infection in recent 3 months
(3) Pregnancy or breastfeeding
(4) Incomplete information or unwillingness to attempt to comply with the intervention

Chuengsamarn et al. [11]27.09 ± 0.5226.84 ± 0.4259.16 ± 11.0459.58 ± 10.71(1) Diabetic patients aged 35 years or older and did not use insulin during the first 5 years of treatment after being diagnosed (with or without symptoms listed in the following inclusion criteria)
(2) Patients with hyperlipidemia (cholesterol ≥ 200 mg/dl, TG ≥ 150 mg/dl, LDL ≥ 100 mg/dl, and HDL ≥ 35 mg/dl)
(3) Patients with hypertension (blood pressure ≥ 130/85 mmHg or take hypertensive drugs)
(4) Obesity (BMI ≥ 25)
(1) Current diagnosis of secondary peripheral arterial disease (PAD) (except listed in the inclusion criteria item 1–4)
(2) Current diagnosis of cardiovascular disease, i.e., coronary arterial disease and cerebrovascular disease
(3) Current diagnosis of end-stage renal function with serum creatinine >2.0 mg/dl or on renal dialysis
(4) Current diagnosis of cirrhosis with ALT ≥3 times the normal range

Khajehdehi et al. [22]52.9 ± 9.252.6 ± 9.7Patients with overt type 2 diabetic nephropathy (proteinuria ≥500 mg/day), who had normal kidney function and well-controlled blood pressure by ACE-I and/or angiotensin receptor blockersPatient with recurrent or relapsing urinary tract infection, bacteriuria, pyuria and/or haematuria, or who failed to sign a written informed consent when risks associated with the trial was carefully outlined for them
Asadi et al. [31, 32]31.1 ± 4.230.8 ± 3.853.3 ± 6.554.6 ± 6.2Age between 30 and 60 years, desire to participate in the study, body mass index between 25 and 39.9, noninsulin type 2 diabetic patients, detection of mild sensorimotor polyneuropathy by using the Toronto questionnaire (score 6–8)Follow a special diet during last month, sensitivity to curcumin, pregnancy and lactation, took any nutritional supplement, vitamin and mineral supplement last month, history of gastrointestinal ulcer and bile duct, neuropathies other than the sensory-motor polyneuropathy diabetic diagnosed by a neurologist, taking gabapentin and any medication, diseases such as cancer, liver, kidney, autoimmune diseases, inflammatory, thyroid and nervous and cardiovascular diseases are diagnosed, and drug use associated with these diseases


Thota et al. [33]30.9 ± 1.231.9 ± 1.755 ± 2.850 ± 2.5(1) Age: 30–70; gender: both male and female
(2) No participation in any clinical trial for at least 3 months
(3) An HbA1c of 5.7%–6.4%
(4) Impaired glucose tolerance (IGT)
(5) 2-hour OGTT plasma glucose greater than or equal to 7.8 mmol/land <11.1 mmol/L
(6) Impaired fasting glucose (IFG)
(7) Fasting plasma venous glucose measurement 6.1–6.9 mmol/L
(8) 12 or more score or high-risk individuals in AUSDRISK assessment tool
(9) BMI between 25 and 45
(1) Pregnancy or lactation
(2) Established type 2 diabetes
(3) Allergic to sea foods
(4) People with gall bladder problems
(5) People currently on medication with erythropoietin
(6) People with anaemia
(7) People with pace maker implants
(8) Currently on medication with aspirin and warfarin
(9) History of severe neurological diseases or seizures
(10) History of new investigational drug three months prior to this trial
(11) Consuming more than 2 servings of oily fish per week
(12) Taking regular dietary supplements known to influence blood glucose level
(13) People taking regular vitamin C supplements
(14) Unwilling to fast for 10 hr before obtaining blood sample. People currently on medication with clopidogrel, ibuprofen, naproxen, dalteparin, enoxaparin, and heparin

Adibian et al. [34]Around 5860 ± 7(1) Tendency to participate
(2) Age range of 40–65
(3) Suffering from diabetes type 2 (for 1 to 10 years)
(4) BMI 18/5–30
(5) Patients with diabetes who administer oral hypoglycemic agents and who do not use them
(1) Patients with liver diseases
(2) Patients with kidney diseases
(3) Patients with inflammatory diseases
(4) Patients with liver diseases
(5) Administering herbal agents
(6) Administering multivitamins and minerals in past 3 months