Ceylon cinnamon does not affect postprandial plasma glucose or insulin in subjects with impaired glucose tolerance

Center for Emergency, Skåne University Hospital, Lund University, Malmö, Sweden.
The British journal of nutrition (Impact Factor: 3.45). 09/2011; 107(12):1845-9. DOI: 10.1017/S0007114511005113
Source: PubMed


Previous studies on healthy subjects have shown that the intake of 6 g Cinnamomum cassia reduces postprandial glucose and that the intake of 3 g C. cassia reduces insulin response, without affecting postprandial glucose concentrations. Coumarin, which may damage the liver, is present in C. cassia, but not in Cinnamomum zeylanicum. The aim of the present study was to study the effect of C. zeylanicum on postprandial concentrations of plasma glucose, insulin, glycaemic index (GI) and insulinaemic index (GII) in subjects with impaired glucose tolerance (IGT). A total of ten subjects with IGT were assessed in a crossover trial. A standard 75 g oral glucose tolerance test (OGTT) was administered together with placebo or C. zeylanicum capsules. Finger-prick capillary blood samples were taken for glucose measurements and venous blood for insulin measurements, before and at 15, 30, 45, 60, 90, 120, 150 and 180 min after the start of the OGTT. The ingestion of 6 g C. zeylanicum had no significant effect on glucose level, insulin response, GI or GII. Ingestion of C. zeylanicum does not affect postprandial plasma glucose or insulin levels in human subjects. The Federal Institute for Risk Assessment in Europe has suggested the replacement of C. cassia by C. zeylanicum or the use of aqueous extracts of C. cassia to lower coumarin exposure. However, the positive effects seen with C. cassia in subjects with poor glycaemic control would then be lost.

Download full-text


Available from: Jan Nilsson, Dec 28, 2013
  • Source
    • "We have previously shown that the ingestion of 6 g C. cassia powder reduces the postprandial blood glucose concentration [11]. However, in a later study, we found that the ingestion of C. zeylanicum did not affect postprandial blood glucose or insulin levels in humans [12]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Background Published studies have reported conflicting results regarding the effects of cinnamon on glucose, lipids and insulin. To gain further insight into the metabolic effects of Cinnamomum cassia we performed randomized, double-blinded placebo-controlled study using euglycaemic-hyperinsulinaemic clamp. Methods Twenty-one subjects with impaired glucose tolerance (IGT) were included in the study (10 or 11 subjects in each group). The study groups were matched for age, gender and body mass index (BMI). Waist-to-hip ratio, BMI, blood pressure, fasting blood glucose, insulin, triglycerides, total cholesterol, low-density lipoprotein, high-density lipoprotein , HbA1c, ASAT, ALAT, bilirubin, ALP, GT and PK were measured before and after the intake of capsules equivalent to 6 g cinnamon twice a day for 12 weeks. The changes in insulin resistance were measured by euglycaemic-hyperinsulinaemic clamp. The Wilcoxon signed rank sum test, the Mann-Whitney U test and Pearson’s chi-squared test were used to analyse the data. Values of p < 0.05 were considered to indicate statistically significant differences. Results At enrolment, the groups were similar in terms of age, gender and BMI. Of the 21 randomized patients with IGT, 17 completed the study (8 controls vs. 9 treated). The ingestion of 6 g cinnamon twice a day for 12 weeks had no significant effect on insulin sensitivity, HbA1c, fasting glucose or BMI. No significant changes were seen in lipids or liver enzymes. Conclusions This study showed that ingestion of 6 g C. cassia twice a day for 12 weeks did not change the insulin sensitivity or liver enzymes in subjects with IGT.
    Nutrition Journal 09/2014; 13(1):96. DOI:10.1186/1475-2891-13-96 · 2.60 Impact Factor
  • Source
    • "Insulin in the brain was shown to inhibit glucose production in the liver and therefore lowered blood glucose levels, while this was absent in insulin resistant states like high fat diet (HFD)- fed mice [14]–[15]. Cinnamon was never shown to affect insulin secretion in vivo [16], and we therefore reasoned that alterations in insulin action in the brain might contribute to the beneficial effect of cinnamon on glucose homeostasis through the brain-liver axis. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Treatment of diabetic subjects with cinnamon demonstrated an improvement in blood glucose concentrations and insulin sensitivity but the underlying mechanisms remained unclear. This work intends to elucidate the impact of cinnamon effects on the brain by using isolated astrocytes, and an obese and diabetic mouse model. Cinnamon components (eugenol, cinnamaldehyde) were added to astrocytes and liver cells to measure insulin signaling and glycogen synthesis. Ob/ob mice were supplemented with extract from cinnamomum zeylanicum for 6 weeks and cortical brain activity, locomotion and energy expenditure were evaluated. Insulin action was determined in brain and liver tissues. Treatment of primary astrocytes with eugenol promoted glycogen synthesis, whereas the effect of cinnamaldehyde was attenuated. In terms of brain function in vivo, cinnamon extract improved insulin sensitivity and brain activity in ob/ob mice, and the insulin-stimulated locomotor activity was improved. In addition, fasting blood glucose levels and glucose tolerance were greatly improved in ob/ob mice due to cinnamon extracts, while insulin secretion was unaltered. This corresponded with lower triglyceride and increased liver glycogen content and improved insulin action in liver tissues. In vitro, Fao cells exposed to cinnamon exhibited no change in insulin action. Together, cinnamon extract improved insulin action in the brain as well as brain activity and locomotion. This specific effect may represent an important central feature of cinnamon in improving insulin action in the brain, and mediates metabolic alterations in the periphery to decrease liver fat and improve glucose homeostasis.
    PLoS ONE 03/2014; 9(3):e92358. DOI:10.1371/journal.pone.0092358 · 3.23 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Herbs and spices have been used since ancient times to not only improve the flavor of edible food but also to prevent and treat chronic health maladies. While the scientific evidence for the use of such common herbs and medicinal plants then had been scarce or lacking, the beneficial effects observed from such use were generally encouraging. It is, therefore, not surprising that the tradition of using such herbs, perhaps even after the advent of modern medicine, has continued. More recently, due to an increased interest in understanding the nutritional effects of herbs/spices more comprehensively, several studies have examined the cellular and molecular modes of action of the active chemical components in herbs and their biological properties. Beneficial actions of herbs/spices include anti-inflammatory, anti-oxidant, anti-hypertensive, gluco-regulatory, and anti-thrombotic effects. One major component of herbs and spices is the polyphenols. Some of the aforementioned properties are attributed to the polyphenols and they are associated with attenuating the metabolic syndrome. Detrimental changes associated with the metabolic syndrome over time affect brain and cognitive function. Metabolic syndrome and type-2 diabetes are also risk factors for Alzheimer's disease and stroke. In addition, the neuroprotective effects of herbs and spices have been demonstrated and, whether directly or indirectly, such beneficial effects may also contribute to an improvement in cognitive function. This review evaluates the current evidence available for herbs/spices in potentially improving the metabolic syndrome, as well as their neuroprotective effects on the brain, and cognitive function in animal and human studies.
    Central Nervous System Agents in Medicinal Chemistry(Formerly Current Medicinal Chemistry - Central Nervous System Agents) 10/2012; 13(1). DOI:10.2174/1871524911313010004
Show more