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4 g of Cinnamon a Day Lowers 24-Hour Blood Glucose in Adults With Prediabetes, 18-Person Crossover Trial Finds
When 18 adults with obesity and prediabetes ate cinnamon for 4 weeks each, their continuous glucose monitoring readings were lower than during the placebo period.
Results of a randomised crossover trial that used continuous glucose monitoring (CGM) to check whether cinnamon, a common cooking spice, affects blood glucose were published in the American Journal of Clinical Nutrition. It was carried out by researchers at the Center for Human Nutrition at the David Geffen School of Medicine at UCLA in the United States.
Crossover in 4-Week Periods on a Low-Polyphenol Diet
The participants were 18 adults (average age 51) who had both obesity and prediabetes. After 2 weeks on a diet low in polyphenols and fibre to equalise conditions, they took 4 g of cinnamon or placebo for 4 weeks each, with a 2-week washout between and then switched. A total of 694 days and 66,624 blood glucose values were collected. The 24-hour blood glucose concentration and the area under the glucose curve during the cinnamon period were significantly lower than during the placebo period, and the average rise to peak glucose was also smaller, at 0.5 mmol/L (9.56 mg/dL) compared with 0.7 mmol/L (11.73 mg/dL) in the placebo period.
In a test in which glucose was drunk along with cinnamon, the incretin hormone GIP (glucose-dependent insulinotropic polypeptide) increased and triglycerides fell. Digestive symptoms such as abdominal pain and bloating did not differ between the two periods, and adherence was above 97% in both periods.
The study had only 18 participants and was short, at 4 weeks. Because it looked at short-term changes in blood glucose readings, it is too early to interpret the findings as an effect on preventing progression of diabetes.
- Double-blind randomised crossover design, 4 g/day of cinnamon vs. placebo for 4 weeks each
- In 66,624 CGM measurements, lower 24-hour glucose, area under the curve and peak rise
- No difference in digestive adverse events
Limitations This is a small, short trial of 18 people over 4 weeks and does not prove an effect on preventing diabetes.
Original research
- Zelicha H, et al. · University of California, Los Angeles. Effect of cinnamon spice on continuously monitored glycemic response in adults with prediabetes: a 4-week randomized controlled crossover trial. The American Journal of Clinical Nutrition. DOI: 10.1016/j.ajcnut.2024.01.008
Copyright in the original research belongs to its publisher and authors.