Cinnamon refers to several plants that belong to the genus Cinnamomum, native to Southeast Asia. The bark, rich in essential oil, is used as a flavoring agent and as a spice. Medicinal uses include appetite stimulation, treatment of arthritis, inflammation, and dyspepsia. In traditional Chinese medicine, cinnamon is used with other herbs in decoctions for cold. In vitro studies have demonstrated that cinnamon has antioxidant (1) (2), anti-inflammatory (3), immunomodulatory (4) (5), antimicrobial (6) and antitumor (7) properties. It has been studied in clinical trials for type 2 diabetes but results are conflicting (8) (9) (10) (11). However, conclusions from a meta-analysis suggest benefits of cinnamon and cinnamon extract in improving fasting blood glucose in patients with type 2 diabetes (12).
Use of cinnamon flavored products has been associated with oral adverse effects (13) (14) (15) (16). Certain cinnamon products are high in coumarin (18) (17) content that can cause hepatotoxicity (19) and can also interact with other drugs (20).