Effect of Curcumin on Glycemic Control in Patients with Type 2 Diabetes: A Systematic Review of Randomized Clinical Trials

Curcumin on Human Health: A Comprehensive Systematic Review and Meta-Analysis of 103 Randomized Controlled Trials

The aim of this meta-analysis was to determine the effect of curcumin on a range of health outcomes. PubMed, EMBASE, Scopus, and Web of Science were searched from inception until September 2023. Randomized clinical trials (RCTs) that compared the effect of Curcuma longa L. with placebo were considered eligible. The risk of bias and overall certainty of evidence were assessed using the Newcastle-Ottawa Scale and Grading of Recommendations Assessment, Development, and Evaluation (GRADE), respectively. We meta-analyzed the effect sizes across eligible studies using the random-effects model. In total, 103 RCTs on 42 outcomes were included, incorporating a total population of 7216 participants. Overall, 23 out of 42 (55%) outcomes reported statistically significant effect sizes. The credibility of the evidence was rated as high for fasting blood sugar (FBS), C-reactive protein (CRP), high-density lipoprotein (HDL), and weight. The remaining outcomes presented moderate (waist circumference [WC], hip circumference [HC], body mass index [BMI], insulin, Homeostatic Model Assessment for Insulin Resistance [HOMA-IR], quantitative insulin-sensitivity check index [QUICKI], leptin, gamma-glutamyl transferase [GGT], glutathione [GSH], and superoxide dismutase [SOD]), low (14 outcomes), or very low (14 outcomes) evidence. In conclusion, curcumin supplementation can modify FBS and some glycemic indices, lipid parameters, as well as inflammatory and oxidative parameters. This updated summary of the accumulated evidence may help inform clinicians and future guidelines regarding medical and scientific interest in curcumin. However, due to limitations in the methodological quality of the included studies, well-designed and long-term RCTs with large sample sizes are needed. Trial registration: PROSPERO: CRD42021251969.

The effect of curcumin-piperine supplementation on lipid profile, glycemic index, inflammation, and blood pressure in patients with type 2 diabetes mellitus and hypertriglyceridemia

Type 2 diabetes mellitus (T2DM) is a metabolic disorder associated with insulin resistance and ensuing dysglycemia, dyslipidemia, and inflammation. Owing to the putative metabolic benefits of curcumin-piperine combination, we explored the efficacy of this combination in improving cardiometabolic indices of patients with T2DM and hypertriglyceridemia. In this double-blind clinical trial, 72 patients with T2DM and hypertriglyceridemia were randomized to receive either a tablet containing 500 mg of curcuminoids plus 5 mg of piperine, or a matched placebo for 12 weeks. Anthropometric indices, blood pressure, glycemic indices, lipid profile, C-reactive protein (CRP), quality of life, and mood were evaluated at baseline and end of the study. After 12 weeks of intervention, the levels of triglycerides (p-value = 0.001) and fasting blood glucose (p-value = 0.004) were significantly reduced in the curcumin-piperine compared with the placebo group. CRP levels were marginally reduced in the curcumin-piperine compared with the placebo group (p-value = 0.081). In addition, energy/fatigue significantly increased in the curcumin-piperine group compared to the control group (p-value = 0.024). However, between-group comparisons showed no significant change in other parameters, including anthropometric indices (waist circumference and body mass index (BMI)), biochemical parameters (low-density lipoprotein (LDL-c), high-density lipoprotein (HDL-c), and insulin), HOMA-IR, blood pressure, quality of life, and DASS-21 items between the studied groups (p-value >0.05). The current study showed that curcumin-piperine supplementation can improve serum CRP, triglycerides, and glucose concentrations in patients with T2DM and hypertriglyceridemia.

The effectiveness of phytosomal curcumin on clinical and laboratory parameters of patients with multiple trauma admitted to the intensive care unit: a double-blind randomized placebo-controlled trial

BACKGROUND

Multiple trauma has serious complications, which increases the risk of morbidity and mortality in the patients. This study aimed to evaluate the impact of supplementation with phytosomal curcumin on clinical and laboratory factors in critically ill patients with multiple trauma.

METHODS

In this double-blind trial, 53 patients with multiple trauma, who were admitted to the intensive care unit (ICU) were randomized to receive either 2 capsules, each capsule containing 250 mg phytosomal (a total of 500 mg daily) as an intervention group or 2 identical capsules (placebo capsules), each containing 250 mg maltodextrin for 7 days. Clinical and laboratory were parameters assessed before and after the intervention.

RESULTS

After seven days of intervention, the mean increase from baseline in the Glasgow coma scale (GCS) score was significantly higher in the curcumin compared with the placebo group (P-value: 0.028), while the reduction in the APACHE-II score in the curcumin group was greater than that the placebo group in a marginally non-significant fashion (P-value: 0.055). Serum total bilirubin (P-value: 0.036) and quantitative C-reactive protein (CRP) (P-value: 0.044) levels significantly decreased while potassium (P-value: 0.01) significantly increased in the curcumin compared with the placebo group. Moreover, supplementation with phytosomal curcumin significantly increased platelet count (P-value: 0.024) as compared with placebo. The 28-day mortality rate was 7.7% (n: 2 patients) and 3.7% (n: 1 patients) in the placebo and curcumin groups, respectively (P-value > 0.05).

CONCLUSION

Phytosomal curcumin had beneficial effects on several clinical and laboratory factors including GCS, APACHEII, serum total bilirubin, CRP, and platelet count in ICU-admitted patients with multiple trauma.

TRIAL REGISTRATION

IRCT20090306001747N1, Available on: https://www.irct.ir/trial/52692 . The first registration date was 12/01/2021.

Effect of nano-curcumin supplementation on cardiometabolic risk factors, physical and psychological quality of life, and depression in patients with coronary slow flow phenomenon: a randomized double-blind clinical trial

BACKGROUND

Extensive evidence has suggested the cardio-protective properties of the polyphenol curcumin. The aim of this study was to investigate the effects of a highly bioavailable curcumin supplement on cardiometabolic risk factors, health-related quality of life, and depression in patients with coronary slow flow phenomenon (CSFP).

METHODS

This randomized double-blind placebo-controlled clinical trial was conducted in 42 patients with CSFP (age 35-70 years, 25 ≤ body mass index < 40 kg/m2). Patients received either 80 mg/day nano-curcumin or placebo for 12 weeks. Serum levels of visfatin, high-sensitivity C-reactive protein (hs-CRP), and glycemic indices were measured before and after the intervention. The short form 36-item quality of life (SF-36) and Beck's Depression Inventory-II (BDI-II) questionnaires were assessed, as well.

RESULTS

No significant improvements were observed in circulating hs-CRP and visfatin following the intervention. A significant increase was observed in pre- to post-fasting blood glucose (- 0.9 ± 12.2 vs. 7.7 ± 12.4 mg/dl, p = 0.02) and hemoglobin A1C (- 0.1 ± 0.8 vs. 0.5 ± 0.8%, p = 0.04) levels, in the placebo compared with the intervention group. Physical (8.2 ± 8.1 vs. - 1.2 ± 6.5, p < 0.001) and mental (6.8 ± 11.8 vs. - 1.1 ± 10.4, p = 0.02) component summary scores were significantly improved in the nano-curcumin than the placebo group. Additionally, the number of patients with lower degrees of depression was significantly better in the intervention than the placebo group following the supplementation (p = 0.046).

CONCLUSION

Curcumin supplementation prevented deterioration of glycemic control and improved physical and psychological quality of life and depression in patients with CSFP.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials (IRCT20131125015536N8), June 19, 2019.

Herbal Products as Complementary or Alternative Medicine for the Management of Hyperglycemia and Dyslipidemia in Patients with Type 2 Diabetes: Current Evidence Based on Findings of Interventional Studies

Type 2 diabetes (T2D) is known as a major public health problem with a noticeable adverse impact on quality of life and health expenditures worldwide. Despite using routine multiple pharmacological and nonpharmacological interventions, including diet therapy and increasing physical activity, controlling this chronic disease remains a challenging issue, and therapeutic goals are often not achieved. Therefore, recently, other therapeutic procedures, such as using herbal products and functional foods as complementary or alternative medicine (CAM), have received great attention as a new approach to managing T2D complications, according to the literature. We reviewed the existing evidence that supports using various fundamental medicinal herbs, including cinnamon, saffron, ginger, jujube, turmeric, and barberry, as CAM adjunctive therapeutic strategies for T2D patients. The current review addressed different aspects of the potential impact of the abovementioned herbal products in improving glycemic indices and lipid profiles, including the effect size reported in the studies, their effective dose, possible side effects, herbs-drug interactions, and their potential action mechanisms.

Ameliorative Effects of Curcumin on Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM), a multifactorial and complicated metabolic disorder, is a growing public health problem. Numerous studies have indicated that bioactive compounds from herbal medicine have beneficial effects on T2DM prevention and treatment, owing to their numerous biological properties. Curcumin, the major curcuminoid of turmeric, is one of the most studied bioactive components of herbal supplements, and has a variety of biological activities. Clinical trials and preclinical research have recently produced compelling data to demonstrate the crucial functions of curcumin against T2DM via several routes. Accordingly, this review systematically summarizes the antidiabetic activity of curcumin, along with various mechanisms. Results showed that effectiveness of curcumin on T2DM is due to it being anti-inflammatory, anti-oxidant, antihyperglycemic, anti-apoptotic, and antihyperlipidemic, among other activities. In light of these results, curcumin may be a promising prevention/treatment choice for T2DM.

Mitochondrial Dysfunction, Oxidative Stress, and Inter-Organ Miscommunications in T2D Progression

Type 2 diabetes (T2D) is a heterogenous disease, and conventionally, peripheral insulin resistance (IR) was thought to precede islet β-cell dysfunction, promoting progression from prediabetes to T2D. New evidence suggests that T2D-lean individuals experience early β-cell dysfunction without significant IR. Regardless of the primary event (i.e., IR vs. β-cell dysfunction) that contributes to dysglycemia, significant early-onset oxidative damage and mitochondrial dysfunction in multiple metabolic tissues may be a driver of T2D onset and progression. Oxidative stress, defined as the generation of reactive oxygen species (ROS), is mediated by hyperglycemia alone or in combination with lipids. Physiological oxidative stress promotes inter-tissue communication, while pathological oxidative stress promotes inter-tissue mis-communication, and new evidence suggests that this is mediated via extracellular vesicles (EVs), including mitochondria containing EVs. Under metabolic-related stress conditions, EV-mediated cross-talk between β-cells and skeletal muscle likely trigger mitochondrial anomalies leading to prediabetes and T2D. This article reviews the underlying molecular mechanisms in ROS-related pathogenesis of prediabetes, including mitophagy and mitochondrial dynamics due to oxidative stress. Further, this review will describe the potential of various therapeutic avenues for attenuating oxidative damage, reversing prediabetes and preventing progression to T2D.

The impact of curcumin on migraine: A comprehensive review

Migraine, a neurovascular condition, is a chronic and lifelong disease that affects about 15% of the population worldwide. Although the exact pathophysiology and etiology of migraine are still unclear, oxidative stress, inflammation, and neuroendocrine imbalances are identified as the critical risk factors for migraine attacks. Curcumin is an active component and a polyphenolic diketone compound extracted from turmeric. Curcumin is a promising candidate for preventing and controlling migraine due to its anti‑inflammatory, antioxidative, anti-protein aggregate, and analgesic effects. In the present review, we have evaluated experimental and clinical studies investigating the impact of liposomal curcumin and nano-curcumin on the frequency and severity of migraine attacks in patients. Although the results are promising, more studies should be conducted in this area to show the exact efficacies of curcumin on clinical symptoms of migraine and investigate its potential mechanisms.

The effect of phytochemicals in prediabetic patients: A systematic review of randomized controlled trials

This study aimed to perform a systematic review to evaluate the effect of phytochemical consumption on the cardiometabolic parameters of prediabetic patients. A comprehensive search was conducted in PubMed, Scopus and ISI Web of Science, and Google Scholar up to June 2022 to find randomized controlled trials investigating the effects of phytochemicals alone or in combination with other nutraceuticals on prediabetic patients. Twenty-three studies with 31 treatment arms comprising 2177 individuals were included in this study. Totally, in 21 arms, phytochemicals had positive effects on at least one measured cardiometabolic factor. In 13 out of 25 arms, fasting blood glucose (FBG) and in 10 out of 22 arms, hemoglobin A1c (HbA1c) significantly decreased compared with the control group. Furthermore, phytochemicals had beneficial effects on 2-h postprandial and postprandial glucose, serum insulin, insulin sensitivity, and insulin resistance as well as inflammatory factors including high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor α (TNF-α), and interleukin 6 (IL-6). Triglyceride (TG) was the abundant improved factor in the lipid profile. However, no sufficient evidence for notable positive effects of phytochemicals on blood pressure and anthropometry indices was observed. Phytochemical supplementation may have beneficial impacts on prediabetic patients by ameliorating glycemic status.

Spices and Biomarkers of COVID-19: A Mechanistic and Therapeutic Perspective

In the face of the COVID-19 pandemic, many people around the world have increased their healthy behaviors to prevent transmission of the virus and potentially improve their immune systems. Therefore, the role of diet and food compounds such as spices with bioactive and antiviral properties may be important in these efforts. In this chapter, we review the efficacy of spices such as turmeric (curcumin), cinnamon, ginger, black pepper, saffron, capsaicin, and cumin by investigating the effects of these compounds of COVID-19 disease severity biomarkers.

Curcumin - The Nutraceutical With Pleiotropic Effects? Which Cardiometabolic Subjects Might Benefit the Most?

Despite continuous advances in pharmacotherapy, atherosclerotic cardiovascular disease remains the world's leading killer. Atherosclerosis relates not only to an increased level of cholesterol, but involves the development of atherosclerotic plaques, which are formed as a result of processes including inflammation and oxidative stress. Therefore, in addition to the classical risk factors for ASCVD (such as type 2 diabetes, overweight, obesity, hypertension and metabolic syndrome), residual risk factors such as inflammation and oxidative stress should also be reduced. The most important intervention in ASCVD is prevention, which includes promoting a healthy diet based on products of natural origin. Curcumin, which is often present in the diet, has been demonstrate to confer several benefits to health. It has been shown in numerous clinical trials that curcumin exhibited anti-diabetic, lipid-lowering, antihypertensive, antioxidant and anti-inflammatory effects, as well as promoting weight loss. All this means that curcumin has a comprehensive impact on the most important risk factors of ASCVD and may be a beneficial support in the treatment of these diseases. Recently, it has also been shown that curcumin may have a beneficial effect on the course of SARS-CoV-2 infection and might be helpful in the prevention of long-COVID complications. The aim of this review is to summarize the current knowledge regarding the safety and efficacy of curcumin in the prevention and treatment of cardiometabolic diseases.