Cassia cinnamon does not change the insulin sensitivity or the liver enzymes in subjects with impaired glucose tolerance

Effects of Cinnamon Supplementation on Lipid Profile: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Since the effects of cinnamon supplementation on lipid profiles are still controversial, this study conducted a meta-analysis of randomized controlled trials to assess the effect of cinnamon supplementation on lipid profiles. The study was designed and conducted according to the guidelines of the 2020 preferred reporting items for systematic reviews and meta-analysis (PRISMA) statements. A systematic and comprehensive search was performed in several databases from inception up to 11 November 2023. The meta-analysis on the impact of Cinnamon on lipid profiles indicates a non-significant overall effect on low-density lipoprotein (weighted mean differences [WMD], -2.48; 95% confidence interval [CI], -9.70, 4.72). However, significant reductions are seen with doses < 500 mg/day (-10.26), and non-significant increases with doses ≥ 500 mg/day (1.18). The overall effect on high-density lipoprotein is non-significant (WMD, 3.97; 95% CI, -7.877, 15.831), showing varying responses at different doses. Triglycerides exhibit a significant overall reduction (WMD, -6.88; 95% CI, -12.62, -1.15), particularly in the < 500 mg/day group. The overall effect on cholesterol is non-significant (WMD, -4.314; 95% CI, -15.011, 6.384), with diverse responses at different doses. High heterogeneity underlines the importance of standardized study designs and further exploration of dosage-specific effects. Findings from this study suggest that cinnamon supplements might be beneficial to modulate the blood lipid profile.

Cinnamon as a Complementary Therapeutic Approach for Dysglycemia and Dyslipidemia Control in Type 2 Diabetes Mellitus and Its Molecular Mechanism of Action: A Review

The scientific evidence that cinnamon may exert beneficial effects on type 2 diabetes mellitus due to the biological activity of its bioactive compounds has been increasing in recent years. This review provides an overview of the effects of cinnamon on clinical parameters of diabetes and summarizes the molecular mechanisms of action of cinnamon on glucose and lipid metabolism. Search criteria include an electronic search using PubMed, Medline, and Cochrane Library databases. English literature references from 2000 up to 2022 were included. Following title and abstract review, full articles that met the inclusion criteria were included. The results from the available evidence revealed that cinnamon improved glycemic and lipidemic indicators. Clinical trials clarified that cinnamon also possesses an anti-inflammatory effect, which may act beneficially in diabetes. Based on in vitro and in vivo studies, cinnamon seems to elicit the regulation of glucose metabolism in tissues by insulin-mimetic effect and enzyme activity improvement. Furthermore, cinnamon seems to decrease cholesterol and fatty acid absorption in the gut. The current literature search showed a considerable number of studies on diabetic subjects. Some limitations in comparing published data should be highlighted, including variability in doses, extracts and species of cinnamon, administration forms, and antidiabetic therapy.

Effects of cinnamon supplementation on lipid profiles among patients with metabolic syndrome and related disorders: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

Studies in animals and humans have reported numerous beneficial effects of cinnamon. However, its hypolipidemic efficacy in patients with metabolic syndrome (MetS) and related disorders is still controversial. This meta-analysis aimed to evaluate the lipid-regulating effects and safety of cinnamon in a population with MetS and related disorders.

METHODS

Studies that met the inclusion criteria were retrieved from PubMed, Embase, Cochrane Library, and Web of Science. Randomized placebo-controlled trials of cinnamon or its extracts in the treatment of MetS and related metabolic diseases were the main eligibility criteria. The Cochrane Handbook was used to guide the study selection, quality assessment, and data analysis. All statistical analyses were performed using Stata 15.0.

RESULTS

Twelve studies involving 773 subjects were included in the meta-analysis. The overall results showed that cinnamon could significantly reduce total cholesterol (weighted mean difference [WMD]: -0.19 mmol/L [-7.34 mg/dL]; 95% confidence interval [CI]: -0.24, -0.14 [-9.27, -5.41]), triglyceride (WMD: -0.10 mmol/L [-8.85 mg/dL]; 95% CI: -0.16, -0.04 [-14.16, -3.54]), and low-density lipoprotein cholesterol (WMD: -0.16 mmol/L [-6.18 mg/dL]; 95% CI: -0.20, -0.11 [-7.72, -4.25]). In the subgroup analysis, cinnamon did not exhibit a significant effect on lipid profiles in European and American patients. Larger doses of cinnamon tended to exhibit better regulation of lipid profiles and high-dose cinnamon (≥1.5 g/d) significantly increased high-density lipoprotein cholesterol (WMD: 0.07 mmol/L [2.70 mg/dL]; 95% CI: 0.03, 0.11 [1.16, 4.25]).

CONCLUSION

The current evidence shows that cinnamon can regulate lipid profiles in patients with metabolic disorders.

Testing the Effects of Cinnamon Extract Supplementation on Inflammation and Oxidative Stress Induced by Acrylamide

We investigated the effects of cinnamon water extract supplementation on inflammation and oxidative stress induced by acrylamide in rats. This revealed acrylamide-intoxicated control group had significant higher levels of malondialdehyde, tumor necrosis factor-alpha (TNF-α), high-sensitive C-reactive protein (hs-CRP), leptin and alanine transaminase, and lower levels of total antioxidant capacity compared to the negative control group. In contrast, cinnamon extract administration remedied the levels of total antioxidant capacity, malondialdehyde, TNF-α, hs-CRP, and leptin in the treatment groups. However, there was no significant effect on adiponectin or liver enzymes. This chapter presents a protocol involving production of the acrylamide-induced oxidative stress model, the aqueous extraction of cinnamon powder, and measurement of inflammatory and oxidative stress markers.

What is the influence of cinnamon supplementation on liver enzymes? A systematic review and meta-analysis of randomized controlled trials

Existing evidence has uncovered the potential health benefits of cinnamon intake; however, its effect on liver function is unclear. Thus, the aim of this systematic review and meta-analysis was to examine the effect of cinnamon supplementation on liver enzymes. Relevant articles were identified through a systematic search in PubMed/Medline, Scopus, Web of Science, Cochrane Library, and Embase up to September 2020. All trials assessing the effect of oral cinnamon supplementation on serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) in adults were included. The pooled effect sizes were obtained using the random-effects model and expressed as mean difference (MD) and 95% confidence intervals (CI). A total of seven original trials (nine treatment arms) involving a total of 256 subjects were included in the final analysis. The pooled analysis indicated that cinnamon supplementation had no significant effect on serum levels of ALT, AST, and ALP. However, there was a significant reduction in ALT levels in patients with type 2 diabetes (MD: -4.01 U/L; 95% CI: -6.86, -1.15) and in trials with low-dose supplementation (<1,500 mg/d), follow-up duration longer than 12 weeks, and in the elderly patients (aged>50 years). The beneficial effects of cinnamon intake were also shown in AST levels in patients with type 2 diabetes and trials with long-term follow-up (>12 weeks). Longer-term, oral cinnamon supplementation may improve serum levels of liver enzymes in patients with type 2 diabetes. Further high-quality studies are needed, especially in populations with abnormal liver enzyme levels, to firmly establish the clinical efficacy of cinnamon on liver function.

The effect of herbs and spices on risk factors for cardiometabolic diseases: a review of human clinical trials

Herbs and spices are recommended to increase flavor and displace salt in the diet. Accumulating evidence suggests herbs and spices may improve risk factors for cardiometabolic diseases. In this narrative review, an overview of evidence from human clinical trials examining the effect of herbs and spices on risk factors for cardiometabolic diseases is provided. Human clinical trials examining supplemental doses of individual spices and herbs, or the active compounds, have yielded some evidence showing improvements to lipid and lipoprotein levels, glycemic control, blood pressure, adiposity, inflammation, and oxidative stress. However, cautious interpretation is warranted because of methodological limitations and substantial between-trial heterogeneity in the findings. Evidence from acute studies suggests intake of mixed herbs and spices as part of a high-saturated fat, high-carbohydrate meal reduces postprandial metabolic impairments, including lipemia, oxidative stress, and endothelial dysfunction. Limited studies have examined the postprandial metabolic effects of incorporating mixed herbs and spices into healthy meals, and, to our knowledge, no trials have assessed the effect of longer-term intake of mixed herbs and spices on risk factors for cardiometabolic diseases. To inform evidence-based guidelines for intake of herbs and spices for general health and cardiometabolic disease risk reduction, rigorously conducted randomized controlled trials are needed, particularly trials examining herb and spice doses that can be incorporated into healthy dietary patterns.

The beneficial effects of cinnamon among patients with metabolic diseases: A systematic review and dose-response meta-analysis of randomized-controlled trials

This systematic review and meta-analysis aims to summarize and conclude the clinical evidence regarding the use of cinnamon among patients with metabolic diseases. A comprehensive literature search without any limitation on language was conducted using the following bibliographical databases: ISI Web of Science, Embase, Scopus, PubMed, and Google Scholar. Search was conducted up to 23 January 2020. A total of 35 clinical trials were included for final analysis. Pooling of results showed a significant reducing effect of cinnamon on total cholesterol (TC) (weighted mean difference (WMD) = -11.67 mg/dL; P = 0.010), triglyceride (TG) (WMD = -16.27 mg/dL; P < 0.001), low density lipoprotein-cholesterol (LDL-C) (WMD = -6.36 mg/dL; P < 0.001), serum glucose (WMD = -11.39 mg/dL; P < 0.001), serum insulin (WMD = -1.27 μIU/mL; P = 0.028), and waist circumstance (WC) (WMD = -1.68 cm; P = 0.016). These lowering effects on TG, TC, LDL-C, and serum glucose levels were robust in studies that used cinnamon supplementation dose ≤1.5 g. Also, our findings of the present meta-analysis showed that cinnamon supplementation could have favorable effects on high density lipoprotein-cholesterol (HDL-C, WMD = 1.35; P = 0.038) as well as systolic (WMD = -3.95 mmHg; P = 0.018) and diastolic (WMD = -3.36; P = 0.001) blood pressure among patients with metabolic diseases. The present meta-analysis suggests that cinnamon might exert beneficial effects on various cardiometabolic risk factors among patients with metabolic diseases.

The effect of cinnamon supplementation on liver enzymes in adults: A systematic review and meta-analysis of randomized controlled trials

AIMS

The aim of this study was to perform a systematic review and meta-analysis of randomized controlled trials (RCTs) to examine the effect of cinnamon supplementation on liver enzymes.

METHODS

A systematic search was performed in electronic databases including PubMed-Medline, Scopus, and ISI Web of Science up to November 2020. We used a random effects model to estimate pooled effect size of alanine aminotransferase (ALT), alkaline phosphatase (ALP), and aspartate aminotransferase (AST) levels.

RESULTS

Seven RCTs (9 treatment arms) fulfilled the eligibility criteria of the present meta-analysis. Overall, meta-analysis could not show any beneficial effect of cinnamon supplementation on AST, ALT, and ALP. Subgroup analyses showed that the effect of cinnamon supplementation on ALT was significant at the dosages of <1500 mg/day (Hedges's: -0.61; 95 % CI: -1.11, -0.10; P = 0.002), in trials lasting>12 weeks (Hedges's: -0.83; 95 % CI: -1.36, -0.30; P = 0.01), and in trials conducted of both gender (Hedges's: -0.72; 95 % CI: -1.45, -0.01; P = 0.04).

CONCLUSION

In summary, cinnamon supplementation had no significant effect on liver enzymes in adults. However, the effect of cinnamon on ALT levels was significant at the dosages of <1500 mg/day, in trials lasting>12 weeks, and in trials conducted of both gender. Nevertheless, further studies should be performed to confirm our results.

Cinnamon extract supplementation improves inflammation and oxidative stress induced by acrylamide: An experimental animal study

OBJECTIVE

Toxic effects of acrylamide on body organs incline researches to prevent or decrease these effects. The objective of the present study was to evaluate the effects of cinnamon extract (CE) supplementation on inflammation and oxidative stress induced by acrylamide in rats.

MATERIALS AND METHODS

Thirty two rats were divided into four groups as follow 1) The control group received distilled water, 2) Acrylamide- intoxicated group was administrated with 35 ml/kg/day acrylamide for two weeks, 3) Acrylamide- intoxicated rats treated with CE 250 mg/kg/day for 28 days, and 4) Acrylamide- intoxicated rats treated with CE 500 mg/kg day for 28 days. Fasting blood sample was obtained for subsequent analysis.

RESULTS

The results showed that acrylamide- intoxicated group had significantly higher levels of malondialdehyde, tumor necrosis factor alpha, high sensitive C reactive protein, leptin and alanine transaminase (p<0.05 to p<0.01) and lower levels of total antioxidant capacity compared to the control group; whereas, cinnamon extract administration remedied levels of total antioxidant capacity, malondialdehyde, tumor necrosis factor alpha, high sensitive C reactive protein and leptin in the treatment groups, but it did not have a significant effect on adiponectin and liver enzymes (p>0.05).

CONCLUSION

This study suggests that cinnamon extract may potentially be effective as a dietary source of bioactive compounds for managing acrylamide intoxication.

Efficacy and safety of cinnamon in type 2 diabetes mellitus and pre-diabetes patients: A meta-analysis and meta-regression

INTRODUCTION

Cinnamon has been used as a dietary component and in the management of diabetes mellitus. This study systematically reviewed and synthesized evidence on the efficacy of cinnamon for the treatment of type 2 diabetes mellitus (T2DM) and pre-diabetes patients.

METHODS

Databases of Web of Sciences, the Cochrane library, PubMed, CINAHL and SCOPUS were searched. Stata version 13 (College Station, Texas 77845 USA) and RevMan var. 5.3 software were used for meta-analysis. Heterogeneity was assessed using Chi-square and I² tests.

RESULTS

Sixteen randomized controlled studies were included in the meta-analysis. Cinnamon significantly reduced fasting blood glucose (FBG) and homeostatic model assessment for insulin resistance (HOMA-IR) level compared to placebo with weighted mean difference (WMD) of -0.545 (95% CI: -0.910, -0.18) mmol/L, I² = 83.6% and -0.714(-1.388, -0.04), I² = 84.4% respectively. There was no significant change in weighted mean difference of glycosylated hemoglobin A1C (HbA1c) % and lipid profiles (mmol/L). Meta-regression did not show any factor significantly affecting the treatment response.

CONCLUSION

Cinnamon reduced FBG and HOMA-IR, level in T2DM and pre-diabetes patients compared to placebo. High heterogeneity observed among included studies warrants further clinical trials after standardization of cinnamon formulation.

Cinnamon extract combined with high-intensity endurance training alleviates metabolic syndrome via non-canonical WNT signaling

OBJECTIVES

The incidence of metabolic syndrome (MetS) in menopausal women is one of the main health care concerns. MetS clusters are related to an imbalance in pro- and anti-inflammatory adipokines such as secreted frizzled-related protein 5 (SFRP5) and wingless-type mammary tumor virus integration site family, member 5A (WNT5A). WNT5A induces an inflammatory state to induce insulin resistance and further pathologic consequences. Recent strategies to prevent progression of MetS to diabetes have focused on conservative treatments such as exercise and herbal medicine. The aim of this study was to investigate the mechanistic effects of cotreatment with cinnamon extract and 12-wk high-intensity endurance training on MetS components considering the non-canonical WNT5A signaling.

METHOD

Thirty-two female ovariectomized Wistar rats were divided into the following four groups (n = 8/group): exercise (Ova+Exe), cinnamon extract (Ova+Cin), exercise with cinnamon extract (Ova+Exe+Cin) and saline (Ova+Sal). One group of rats undergoing surgery without removal of the ovaries was considered as a sham. After 3 mo of experimental intervention, waist circumference, serum concentrations of glucose, insulin, lipid profile, tumor necrosis factor-α, WNT5A, and SFRP5 were measured.

RESULTS

Data showed a significant reduction in serum glucose, low-density lipoprotein, homeostasis model assessment estimate of insulin resistance, and tumor necrosis factor-α, but an increase in SFRP5 level in Ova+Exe, Ova+Cin and Ova +Exe+Cin groups compared with Ova+Sal group (P < 0.05). Serum WNT5A significantly was reduced only in Ova+Exe+Cin group (P = 0.02).

CONCLUSION

The present study indicated that high-endurance training combined with aqueous cinnamon extract supplementation for 12 wk more efficiently alleviated insulin resistance and metabolic dysfunctions via reduction in noncanonical WNT signaling in ovariectomized rats.

Effects of medicinal food plants on impaired glucose tolerance: A systematic review of randomized controlled trials

BACKGROUND

The objective of this systematic review was to assess available scientific data on the efficacy and safety of medicinal food plants for the treatment of impaired glucose tolerance.

METHODS

We included randomized controlled trials (RCTs) with a minimum follow-up period of 6weeks. The diagnosis was determined by fasting plasma glucose values after two-hour oral glucose tolerance testing (OGTT). Two authors independently extracted data and evaluated bias. The Cochrane tool of risk of Bias Tool was used.

RESULTS

This review included ten trials. Most studies were highly biased as data were incomplete or reporting was selective. The two-hour fasting plasma glucose after the curcumin extract intervention showed statistical significance after 3, 6 and 9months: p<0.01. Also, glycosylated haemoglobin levels A1c (HbA1c) values after curcumin extract intervention showed statistical significance after 3, 6 and 9months: p<0.01. Insulin resistance (HOMA-IR) after curcumin extract intervention showed statistical significance after 6months and after 9months: p<0.05 and p<0.01.

CONCLUSIONS

Curcumin has shown the confident results to be effective for the treatment of impaired glucose tolerance. Fenugreek and flaxseed may also be effective, but due to low quality of these studies the results must be interpreted with caution.

Comparative effect of cinnamon and Ibuprofen for treatment of primary dysmenorrhea: a randomized double-blind clinical trial

BACKGROUND AND AIMS

Primary dysmenorrheal has a negative impact on women's quality of life. The purpose of this study was to compare the effect of Cinnamon and Ibuprofen for treatment of primary dysmenorrheal in a sample of Iranian female college students from Ilam University of Medical Sciences (western Iran).

MATERIALS AND METHODS

In a randomized, double-blind trial, out of 114, control group received placebo (empty capsules contain starch, TDS, n= 38) a test group received Ibuprofen (capsule containing 400mg Ibuprofen, TDS, n=38), or another test group received Cinnamon (capsule containing 420 mg Cinnamon, TDS, n= 38) in 24 h. To determine severity of pain, we used the VAS scale. Pain intensity and duration of pain were monitored in the group during first 72 h of cycle.

RESULTS

The mean pain severity score and mean duration of pain in Ibuprofen and Cinnamon were less than placebo group respectively (p< 0.001). Of 4 hours after the intervention there were no statistically significant differences between the Cinnamon and placebo group (p> 0.05). Of eight hours after the intervention, the mean pain severity in the cinnamon group was significantly lower than placebo group (p< 0.001). At various time intervals the mean pain severity in the Ibuprofen group were significantly less than Cinnamon and placebo groups (p< 0.001).

CONCLUSION

Cinnamon compared with placebo significantly reduced the severity and duration of pain during menstruation, but this effect was lower compared with Ibuprofen. Cinnamon can be regarded as a safe and effective treatment for primary dysmenorrhea. More researches are recommended to study the efficacy of Cinnamon on reducing menstrual bleeding.