Current evidence suggests benefits of cinnamon for lowering glucose, cholesterol and triglyceride levels.
Cinnamon refers to several plants native to Southeast Asia. The bark, rich in essential oil, is used as a flavoring agent and as a spice. Cinnamon has a long history of use as an herbal medicine. Laboratory studies have shown that cinnamon has antibacterial, anti-inflammatory, and antioxidant properties. It was also shown to lower blood glucose levels in patients with type 2 diabetes, to lower total cholesterol and triglyceride levels, to reduce dental plaque and gingivitis, and to improve metabolic syndrome (metabolic disorders that increase the risk of cardiovascular disease, stroke and diabetes). Topical use of a cinnamon containing ointment was shown to help relieve perineal pain and improved healing of episiotomy incision in postpartum women.
Diabetes
A systematic reviews and meta analysis showed that cinnamon is useful in lowering blood glucose, lipids, and insulin levels
Inflammation
Laboratory studies showed that cinnamon can reduce inflammation. Human data are lacking.
Arthritis
Cinnamon is used in traditional medicine for arthritis but there is no scientific evidence to support this claim.
Some cinnamon products contain high levels of coumarin, a natural constituent, that can cause liver damage.
Cytochrome P450 2C9 , 3A4, 2A6, 2D substrates: Cinnamon may increase the risk of side effects of these drugs.
Statins: When taken along with statins, cinnamon has been reported to cause hepatitis.
Pioglitazone: When used together, cinnamon increased the bioavailability of Pioglitzone (antidiabetic drug).
Oral lesions were shown to be associated with the use of oral cinnamon products like herbal toothpaste and chewing gum.
Occupational allergy has been reported with use of cinnamon (due to exposure to its compounds).
Use of vaginal suppositories containing cinnamon oil resulted in allergic contact dermatitis.
Generalized systemic dermatitis after consuming herbal tea that contained large amounts of cinnamon.
A systematic review of adverse effects reported that gastrointestinal disorders and allergic reactions were most frequent after consuming cinnamon, but self-limiting in many cases.
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 along with other herbs in decoctions to treat colds. In vitro studies have demonstrated that cinnamon has antioxidant (1)(2), anti-inflammatory (3), immunomodulatory (4)(5), antimicrobial (6), antitumor (7) , and antiestrogenic (26) properties.
Cinnamon has been studied in clinical trials for type 2 diabetes but results are conflicting (8)(9)(10)(11)(37). However, conclusions of a meta analysis and a review suggest improvements in glycemic control with cinnamon and its extracts in patients with type 2 diabetes (12)(36). According to another meta analysis, supplementation also affected significant reductions in blood triglycerides and total cholesterol concentrations (38). Additional studies reported benefits of cinnamon extracts in decreasing insulin resistance in women with polycystic ovary syndrome (POCS) (39); in improving metabolic syndrome (40); for reducing dental plaque and gingivitis in healthy adults (32); and topical use of a cinnamon ointment alleviated perineal pain and improved healing of episiotomy incision in postpartum women (33).
Certain cinnamon products are high in coumarin (18)(17) content that can cause hepatotoxicity (19) and can also interact with other prescription drugs (20).
Cinnamon bark
Diabetes
Stomach ulcers
Gingivitis
Inflammation
Arthritis
Hydroxycinnamaldehyde, a compound present in cinnamon, exerts anti-inflammatory effects by inhibiting nitric oxide production by inhibiting nuclear factor (NF)-kappaB (3). Cinnamon also inhibits hepatic HMG-CoA reductase activity (24) and reduces the level of blood lipids in animals and humans (10). In another study, methylhydroxychalcone polymer, isolated from cinnamon, was shown to mimic insulin by activating the insulin receptors (23).
Cinnamon extract binds to estrogen-receptor beta and has a direct stimulatory effect on bone formation (25). The n-hexane extract of cinnamon has antiestrogenic activity (26). In other studies, cinnamon extract was shown to inhibit nuclear factor (NF) kappaB and AP1 leading to apoptosis (7). It also showed antiangiogenic effects by inhibiting the vascular endothelial growth factor (VEGF) (22).
Plasma cell gingivitis (PCG) and stomatitis: Following use of oral cinnamon products including toothpaste and chewing gum (13)(15)(16)(27)(34)
Occupational allergy in a baker: Due to exposure to cinnamal, a compound in cinnamon (28)
Allergic contact dermatits: In an 18-year-old following use of vaginal suppositories containing cinnamon oil (29)
Generalized systemic dermatitis: In a 26-year old after drinking several cups of herbal tea containing large amounts of cinnamon (41)
A systematic review of adverse effects reported that gastrointestinal disorders and allergic reactions were most frequent after consuming cinnamon, but self-limiting in many cases (42).
Cytochrome P450 substrates: Cinnamon inhibits cytochrome P450 2C9 and 3A4 (31), 2A6 (43), 2D (44), and may interfere with the actions of drugs metabolized by these enzyme (31).
Statins: When taken along with statins, cinnamon has been reported to cause hepatitis (35).
Pioglitazone: Cinnamon enhanced bioavailability upon concomitant use (45).
Cinnamon may lower blood glucose and cholesterol levels but the evidence is mixed (8)(10).
Theoretically, cinnamon may increase prothrombin time (30).
Federal Institute for Risk Assessment. Selected Questions about coumarin in cinnamon and other foods. http://www.bfr.bund.de/cd/8487. Accessed October 10, 2018.
