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

Abstract

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: À4.01 U/L; 95% CI: À6.86, À1.15) 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.

Safety of Cinnamon: An Umbrella Review of Meta-Analyses and Systematic Reviews of Randomized Clinical Trials

“…We finally included four studies that fulfilled the eligibility criteria. Of these four studies, the study by Mousavi et al (2021 ) included alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase levels as outcomes that would indicate the safety of cinnamon supplementation with respect to liver enzymes. The authors found that cinnamon improved serum levels of hepatic enzymes in patients with type 2 diabetes.…”

“…In terms of publication bias, Mousavi et al ( Mousavi et al, 2021 ) evaluated this bias using a funnel plot analysis and conducted Egger’s test. They found no small-study effects and no excessive significance bias.…”

“…The aforementioned clinical benefits have contributed to cinnamon consumption; however, there is evidence that cinnamon may have adverse effects. Coumarin, one of the main components of cinnamon, has been indicated to have hepatotoxic, and carcinogenic effects ( Brancheau et al, 2015 ; Mousavi et al, 2021 ). The dose and duration of cinnamon supplementation in a meta-analysis included in this review did not exceed the daily tolerable coumarin intake.…”

Does Ashwagandha supplementation have a beneficial effect on the management of anxiety and stress? A systematic review and meta‐analysis of randomized controlled trials

“…The I ‐squared ( I 2 ) index was used to assess study heterogeneity. If the I 2 was greater than 50%, there was heterogeneity between the included trials (Mousavi et al, 2021). A sensitivity analysis was carried out to assess the potential bias and robustness of the overall effect estimate (Mousavi et al, 2020).…”

Does folic acid supplementation have a positive effect on improving memory? A systematic review and meta-analysis of randomized controlled trials

“…If the I 2 was greater than 50%, there was heterogeneity between the included trials ( Mousavi et al, 2022 ). A sensitivity analysis was used to evaluate the potential bias and robustness of the overall effect estimate ( Mousavi et al, 2021 ). To determine the presence of publication bias, Egger’s regression test as well as funnel plot were used.…”