Effects of Cinnamon on Blood Glucose Levels

Abstract

Diseases such as diabetes and cardiovascular events can be a result of poor glycaemic control. This is because high levels of blood glucose levels can lead to oxidative stress, which is thought to be linked to insulin resistance. Cinnamon is a spice that is thought to possess many different medicinal properties such as anti-diabetic and antimicrobial effects. The aim of this study was to investigate the effects of cinnamon tea made from Cinnamomum cassia on fasting blood glucose levels in healthy non-diabetic adults. Subjects took part in an oral glucose tolerance test with either cinnamon tea or water placebo in a randomised, placebo-controlled, cross-over study. The results showed that cinnamon tea slightly, but not significantly decreased the mean blood glucose levels 60 minutes after the oral glucose tolerance test (from 7.99 ± 1.51 mmol/L to 7.58 ± 1.76 mmol/L) and maximum blood glucose concentration (from 9.33 ± 1.08 mmol/L to 8.96 ± 1.92 mmol/L) compared to water placebo. FRAP and Folin analysis also showed that cinnamon tea that had been brewed for 12 hours had increased more than 2-fold and 3-fold, respectively, compared to cinnamon tea that had been left to brew for 30 minutes. FRAP and Folin analysis also showed that the 30 minutes cinnamon tea was 153-fold and 12-fold increase compared to the placebo water group. This study suggests that further research should be done on Cinnamomum cassia to investigate if larger amounts of cinnamon in the tea would produce more significant results in reducing blood glucose levels. Keywords: cinnamon, glucose, antioxidants, polyphenols, diabetes