An evidence-based systematic review of cinnamon (Cinnamomum spp.) by the Natural Standard Research Collaboration.
OBJECTIVE To identify published studies evaluating the effects of cinnamon on glycaemic control. DESIGN Literature search. METHOD The Medline database was searched using all possible combinations of the words and medical subject headings (MeSH) 'cinnamon', 'diabetes mellitus', 'HbA1C' and 'glucose'. All human or animal studies in which cinnamon was administered as intervention were included. RESULTS Several animal studies and 5 randomized placebo-controlled trials in humans were found. Most of the animal studies described beneficial effects of cinnamon on glycaemic control. One placebo-controlled trial in patients with type 2 diabetes found that cinnamon intake was associated with favourable effects on fasting plasma glucose. None of the studies reported an improvement in HbA1C. A study in patients with type 1 diabetes found that cinnamon had no effect. CONCLUSION Based on the currently available evidence, cinnamon should not be recommended for the improvement ofglycaemic control.