In a recent study published in The American Journal of Clinical Nutrition, researchers investigated the glucose-modulating effects of cinnamon spice when added every day to regular meals. While studies on the subject have been conducted prior to now, their results remain confounding. The current study uses a 12-week-long randomized, controlled, double-blind, crossover trial and divulges that just 4 g of cinnamon supplements taken every day over 4 weeks significantly reduces blood glucose concentrations in obese and obese prediabetic individuals.

While the underlying mechanisms via which cinnamon controls glucose metabolism stays the subject of future research, this study’s findings suggest the gut microbiome’s profound role within the observed association. The study highlights the advantages of cinnamon and other polyphenol-rich spices in deterring chronic diseases and improving public health.

Study: Effect of cinnamon spice on constantly monitored glycemic response in adults with prediabetes: a 4-week randomized controlled crossover trial. Image Credit: Virrage Images / Shutterstock

Cinnamon, what medical potential does it have?

Cinnamon is a spice obtained from the inner bark of several Cinnamomum genus tree species. Despite greater than 250 species belonging to the genus, only 4 are commercially harvested. Traditionally, cinnamon has been utilized in several global cultures as an fragrant spice and, less often, as an antimicrobial, anti-inflammatory, and food-preserving agent.

Clinically, cinnamon has been investigated for its potential advantages attributable to it being a wealthy source of polyphenols, that are assumed to enhance glucose metabolism and homeostasis. Nevertheless, previous studies present widely various results, with some attesting to its glucose-modulating advantages while others describe no such association. Unfortunately, most studies in the sector have suboptimal effect sizes Ess), suggesting the necessity for an investigation comparing cinnamon and its lack thereof in a clinically controlled setting to elucidate the advantages of the spice.

Concerning the study

The current study comprises a randomized, controlled, double-anonymized crossover trial comprising a 2-week run-in phase and 4 weeks of intervention (cinnamon supplementation). The study was carried out between March and December 2021 and included adult participants above the age of 18 with clinically confirmed obesity or obese diagnosis.

Study screening involved a comprehensive metabolic screening and glycated hemoglobin assessment for baseline readings to be certain that participants previously consumed low polyphenol diets. Participants were assigned to the case (cinnamon supplementation) and control (placebo) cohorts, following which the run-in phase commenced. This phase is characterised by two weeks of low polyphenol-containing beige diets (included foods are typically beige in color and wealthy in easy carbohydrates). Participants were required to abstain from cinnamon and its products during this time.

Following the run-in, the four-week intervention commenced. 4 grams of cinnamon (or equivalent placebo) were provided to participants every day in the shape of 32 cinnamon capsules (250 g per day). Day by day food intake records were maintained, as was dietary compliance. Continuous glucose monitoring (CGM) was performed using an Abbott Diabetes Care flash system. Any discomfort, especially digestive or abdominal, was patient-recorded and reported.

To further unravel the real-world advantages of cinnamon supplementation when the spice is often consumed as a component of a meal, oral glucose tolerance testing (OGTT) was carried out via an indwelling catheter inserted into participants’ forearms.

Study findings

Nineteen participants successfully met inclusion criteria screening requirements and were enrolled within the study. One in all these, one participant failed to finish the study (OGTT method-associated discomfort) and was faraway from the analyses. Of the remaining 18 participants, 72% were female (m = 13) with mean ages and weights of 51.1 years and 84.6 kg/m², respectively. Computer-aided evaluations of variables across case and control cohorts found no significantly differing parameters at baseline.

Continuous glucose monitoring (CGM) enabled the entire data recording of 694 participant follow-up days and 66,624 glucose readings. Results from this test revealed that peak glucose values reduced significantly within the case-cohort (Δ = 9.56 ± 9.1 mg/dL) in comparison with controls (Δ = 11.73 ± 8.0 mg/dL).

“The difference within the glucose trajectories between cinnamon and placebo remained strongly significant after adjusting for age, sex, and HbA1c at baseline/FPG at baseline/systolic or diastolic blood pressure at baseline performed in multivariable repeated measurement models (P < 0.001)."

CGM findings were validated and prolonged by OGTT investigations, which found that the realm under the curve (AUC) values within the cinnamon cohort were substantially higher by the top of the study compared to baseline readings at study initiation. Baseline AUC values were observed to extend from 31,885.1 to 43,592.9 over the 4 intervention weeks.

Encouragingly, capsule ingestion adherence of each cohorts was high and indistinguishable (97.6 within the cinnamon group and 97.9 within the placebo group), validating the statistical weight of those results. No patients reported any alarmingly hostile unintended effects through the study, and reported digestive symptoms between cohorts remained comparatively stable during every follow-up trial.

Conclusions

In the current study, researchers used a double-blind, crossover trial of 18 obese and obese American adults to analyze any potential association between cinnamon consumption and glucose homeostasis in these individuals. Study findings revealed that cinnamon substantially lowers fasting blood glucose levels in patients in comparison with controls (Δ = 9.56 ± 9.1 and Δ = 11.73 ± 8.0 mg/dL, respectively).

Postprandial glucose and insulin concentrations didn’t differ notably between cases and controls. Nevertheless, trends in glucose modulation, especially AUC values, modified faster, more dramatically, and beneficially within the case-cohort. While the particular bioactive cinnamon-contained compounds liable for these observations remain elusive, this study highlights that even 4 g of cinnamon, consumed as garnishing or spice with every day meals, may improve prediabetes status and reduce diabetes risk in obese individuals.