Cinammon (Cinnamomum Spp.) and Type 2 Diabetes Mellitus

Abstract 
Spices such as cinnamon (Cinnamomum Spp.) have been of interest due to their phytochemical composition that exert hypoglycemic effects with potential for management of type 2 diabetes mellitus (T2DM). We summarize data from 27 manuscripts that include, one book chapter, 3 review articles, 10 randomized controlled trials, 4 systematic reviews with meta-analysis, and 9 preclinical studies. The most frequently used cinnamon variety was Cinnamomum cassia rather than the Cinnamomum zeylanicum, whereas outcomes were defined as fasting blood glucose, glycated hemoglobin, and oral glucose tolerance test. A great variability in methodology such as different doses (from 120 mg to 6 g), duration of intervention, data retrieved and use of different concomitant medication, were found to be key aspects of most of trials and systematic reviews with meta-analysis available to date. Low quality studies have been made in most cases with a lot of heterogeneity clouding significance of results. More research needs to be done in order to yield accurate evidence for evidence-based recommendations. Its use is not currently a reliable nor advisable option for the treatment of T2DM.