There is mixed evidence on cinnamon’s ability to lower 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 but more studies are needed to confirm such effects.
Diabetes
Evidence is mixed: A few clinical trials have shown that cinnamon is beneficial in lowering blood glucose, lipids, and insulin levels; other studies have demonstrated no such effects.
Stomach Ulcer
In one clinical trial, cinnamon extract proved ineffective in eradicating an H. pylori infection.
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 substrates: Cinnamon may increase the risk of side effects of these drugs.
Hypoglycemics: Cinnamon extract may have an additive effect with blood glucose-lowering medications.
Anticoagulants: Because cinnamon has coumarin, it may have additive effects when used with blood-thinning medications.
Statins: When taken along with statins, cinnamon has been reported to cause hepatitis.
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.
Use of vaginal suppositories containing cinnamon oil resulted in allergic contact dermatitis in an 18-year-old woman.
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.
Cinnamon has been studied in clinical trials for type 2 diabetes but results are conflicting (8)(9)(10)(11). However, conclusions of a meta analysis and a review suggest improvements in glycemic control with cinnamon and cinnamon extracts in patients with type 2 diabetes (12)(36). In other studies, a cinnamon extract was found effective in 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).
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).
Cinnamon bark
Diabetes
Stomach ulcers
Inflammation
Arthritis
Hydroxycinnamaldehyde, a compound present in cinnamon, exerts anti-inflammatory effects by inhibiting nitric oxide production via inhibition of 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 NFkappaB and AP1 leading to apoptosis (7). It also showed antiangiogenic effects by inhibiting the vascular endothelial growth factor (VEGF) (22).
Patients taking blood glucose-lowering or blood-thinning medications should use cinnamon extract with caution.
Cinnamon was shown to have both estrogenic and antiestrogenic activities in vitro (24)(25). Patients with hormone sensitive disease should use caution.
Plasma cell gingivitis (PCG) and stomatitis were shown to be associated with the use of oral cinnamon products including toothpaste and chewing gum (13)(15)(16)(27)(34).
Occupational allergy has been reported with use of cinnamon (28).
Use of vaginal suppositories containing cinnamon oil resulted in allergic contact dermatitis in an 18-year-old woman (29)
Cytochrome P450 substrates: Cinnamon inhibits cytochrome P450 2C9 and 3A4 and may interfere with the actions of drugs metabolized by these enzyme (31).
Hypoglycemics: Cinnamon extract may have an additive effect with blood glucose-lowering medications.
Anticoagulants: Because cinnamon has coumarin, it can interact with blood-thinning medications.
Statins: When taken along with statins, cinnamon has been reported to cause hepatitis (35).
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 February 18, 2008.
