Four trials reported data on adverse events for 264 participants;
including three events in 133 participants receiving cinnamon,
and four events in 131 participants receiving control. Crawford
2009 observed that one participant in the treatment group developed
a rash after discontinuing cinnamon. Rosado 2010 identified
one case of nausea in the control group. Altschuler 2007
reported that one participant in the treatment group developed
hives,while another had a hypoglycaemic seizure. In the same trial,
two participants from the control group reported adverse events;
one reported stomach aches and the other frequent illness. All four
participants withdrew fromthe study. Akilen 2010 stated that one
participant from the placebo group developed mild gastric pain
for two days. There was no statistically significant difference in the
rate of adverse events between cinnamon and placebo groups (OR
0.83; 95% CI 0.22 to 3.07; P = 0.77; n = 264; 4 trials) (Analysis
1.4, Figure 5). There also was no significant difference in the OR
of any adverse event between treatment groups in the subgroup
analyses for dosage (Analysis 2.3) and study duration (Analysis
2.4), or the sensitivity analysis restricted to trials with moderate
risk of bias (OR 0.31; 95% CI 0.03 to 3.07; P = 0.32; n = 98; 2
trials)