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

Dan-Tong Gu, Tao-Hsin Tung, Zhu Liduzi Jiesisibieke, Ching-Wen Chien, Wen-Yi Liu

Journal: Frontiers in pharmacology 2022;12():790901

PMID: 35115937

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Plain Language Summary

Cinnamon is a common spice that contains manganese, iron, dietary fibre, calcium, their derivatives, and other related compounds. Despite the several clinical benefits afforded by cinnamon, concerns about its safety persist. The aim of this study was to elucidate the safety of cinnamon which may facilitate a better understanding of the side effects of cinnamon among healthcare workers and policy makers. This study is an umbrella review of four systematic reviews and meta-analysis. Results show that there was no significant difference in adverse events between cinnamon and placebo. Furthermore, it has benefits in the treatment of a variety of diseases, such as type 2 diabetes and cancer. Authors conclude that cinnamon can be used as an adjunctive compound in clinical practice and appears safe in terms of side effects.

Abstract

Many evidence-based studies have indicated that cinnamon has therapeutic effects. However, it may not be entirely safe and its adverse effects may be ignored. The present umbrella review was conducted to elucidate the safety of cinnamon. Pertinent meta-analyses and systematic reviews of randomized controlled trials on cinnamon use in humans were identified by searching PubMed, EMBASE, and the Cochrane Library from their inception to September 15, 2021. All meta-analyses and systematic reviews on the safety or adverse effects of cinnamon were considered. PRISMA 2020 was used as the standard of reporting (PRISMA registration ID: 286746). We identified three meta-analyses and one systematic review that described the safety of cinnamon. The quality of the meta-analysis and systematic reviews was evaluated using "Assessing the Methodological Quality of Systematic Reviews." Their quality was rated as low in two (50%) instances and moderate in two (50%). There were no significant toxic- or side effects between cinnamon group and placebo group regardless of dose and duration. There is evidence to support that the use of cinnamon has no adverse reactions. It can improve the health status of patients as an adjuvant treatment. Future studies exploring better profile risks and protective factors for cinnamon use-related adverse effect are needed, in order that preventive approaches can be developed.

Address: Institute of Otolaryngology, Clinical Research Center, Fudan University Affiliated Eye and ENT Hospital, Shanghai, China.; Evidence-based Medicine Center, Taizhou Hospital of Zhejiang Province Affiliated with Wenzhou Medical University, Linhai, China.; Institute for Hospital Management, Tsing Hua University, Shenzhen, China.; Department of Health Policy and Management, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States.; Shanghai Bluecross Medical Science Institute, Shanghai, China.

DOI: 10.3389/fphar.2021.790901