Abstract

Background: Cinnamon preparations have been shown to reduce blood glucose and improve HbA_1c in patients with Type 2 Diabetes mellitus. However, some meta-analyses have resulted in inconclusive data due to the heterogeneity of materials and patients in various published trials. In order to evaluate the effects of a cinnamon extract preparation on metabolic control, we performed a double-blind randomized placebo-controlled prospective study with a cinnamon extract from Cinnamomum aromaticum (C. cassia).

Subjects/Methods: We included 109 patients with type 2 diabetes and suboptimal glycemic control (HbA1 ≥ 7.0). Patients were randomized to receive one capsule daily containing 314 mg of cinnamon extract or placebo for four months on top of their regular treatment. Observation parameters were changes in HbA_1c, HOMA-IR, hsCRP, adiponectin and lipids.

Results: HbA_1c improved from 7.92 ± 0.98% to 7.39 ± 0.98% in the cinnamon group (-7%, p < 0.005) and from 7.73 ± 0.80% to 7.44 ± 0.94% in the placebo group (-3.8%; p < 0.05). Significant differences in favour of the cinnamon intervention were seen for almost all indicators of insulin resistance, inflammation and lipid distribution. Both treatments were well tolerated.

Conclusion: We found a consistent improvement in markers of glycaemic control, chronic systemic inflammation and insulin resistance during supplementation with cinnamon extract in comparison to further deteriorations with placebo. These results support the use of cinnamon extracts as dietary supplement for patients with type 2 diabetes and metabolic syndrome.

Keywords: Cinnamomum; Cinnamon; Type 2 Diabetes and Metabolic Syndrome

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