According to the American Diabetes Association, as much as 38% of the U.S. population may have prediabetes, though it usually stays undetected.

    Progression to type 2 diabetes occurs at a rate of 3–11%. Lifestyle changes can prevent it, as can some pharmaceuticals, but long-term adherence to these interventions can be problematic.

    In experimental models of diabetes, cinnamon improved blood glucose control through several mechanisms. Moreover, in randomized controlled trials, regular supplementation with cinnamon was shown to reduce fasting blood glucose by 10–15%. The present study examined the effects of cinnamon supplementation on glucose homeostasis in prediabetics.

    The study

    In this 12-week randomized controlled trial, 54 prediabetics took 500 mg of cinnamon (specifically, Cinnamomum burmannii) (n=27) or a placebo (n=27) thrice a day.

    The primary outcome was the change in fasting plasma glucose. The two secondary outcomes were the change in 2-hour plasma glucose and the change in area under the curve (AUC) for plasma glucose from an oral glucose tolerance test (OGTT).

    The results

    From baseline to 12 weeks, fasting plasma glucose increased only in the placebo group. At 12 weeks, the average between-group difference was 5 mg/dL, which was statistically significant.

    AUC for plasma glucose and 2-hour plasma glucose (both from the OGTT) decreased only in the cinnamon group, and the between-group difference was statistically significant here too.

    These results suggest that cinnamon supplementation reduces the rate of progression from prediabetes to diabetes. Longer trials in diverse prediabetic populations and comparing different dosages are now needed.

    This Study Summary was published on January 5, 2021.