Cinnamomum verum (Ceylon) and Cinnamomum cassia (cassia) · herb
Evidence tier: weak
Improves insulin sensitivity, lowers post meal glucose spikes, and has antimicrobial properties, Ceylon cinnamon is the preferred form for blood sugar support
Cinnamon's proanthocyanidins and cinnamaldehyde are reported in laboratory work to make the insulin receptor more responsive and to help move the GLUT4 glucose transporter to the cell surface, so cells take up more glucose for the same insulin. This is a cell and animal level account. Cochrane's finding that fasting glucose, HbA1c and insulin do not reliably move in people is the reason the mechanism cannot be quoted as if it were an established human effect.
Weak, and the safety half matters more than the efficacy half. EFFICACY: Cochrane (Leach MJ and Kumar S, 2012, PMID 22972104, 10 RCTs, 577 people with diabetes, mean dose 2 g daily) concluded there is INSUFFICIENT evidence to support the use of cinnamon for type 1 or type 2 diabetes. It found no statistically significant difference in HbA1c, serum insulin or post meal glucose, and called the effect on fasting blood glucose inconclusive. NCCIH's position is that studies of cinnamon for blood sugar are small, differ from one another in formulation, dose, duration and participants, and produce no clear conclusions, and that cinnamon has not been shown to effectively treat any health problem. Later meta analyses do report fasting glucose reductions, but with severe between study heterogeneity (I squared around 66 percent and higher) and almost entirely in people with DIAGNOSED type 2 diabetes or PCOS, which is a disease population and cannot carry a consumer claim. SAFETY, and this is the load bearing fact: cassia cinnamon, which is the cheap grocery store and supplement default, contains COUMARIN, which is hepatotoxic in a susceptible subgroup of people. EFSA set a tolerable daily intake of 0.1 mg coumarin per kg of body weight in 2004, a figure Germany's BfR endorses. Cassia averages around 3,000 mg of coumarin per kg of cinnamon and has been measured as high as 10,000 mg per kg. At the average figure, a 70 kg adult reaches the TDI at roughly 2.3 g of cassia powder daily, which is INSIDE the dose range these very trials used. Ceylon cinnamon, Cinnamomum verum, contains negligible coumarin. The distinction between the two species is not a nicety, it is the difference between a spice and a daily hepatotoxin exposure, and most products on the shelf are cassia.
Trials used a mean of about 2 g daily, and Cochrane found that dose insufficiently supported. Any therapeutic dose should be CEYLON (Cinnamomum verum). At cassia's average coumarin content, roughly 2 g daily takes a 70 kg adult to the EFSA tolerable daily intake for coumarin, so the trial dose and the safety ceiling collide.
Take 1 to 3g of Ceylon cinnamon daily with meals. Note: Cassia cinnamon (common grocery store variety) contains coumarin and should not be taken in high doses long term. Use certified Ceylon cinnamon supplements.
Onset: ~14 days
Ceylon cinnamon is safe at normal food and supplemental doses. Cassia cinnamon at high daily therapeutic doses may cause liver damage (coumarin hepatotoxicity). May enhance glucose lowering medications. Avoid therapeutic doses in first trimester pregnancy.
Pregnancy: caution
Breastfeeding: safe
One of the oldest spices used medicinally, documented in Chinese and Ayurvedic texts dating back thousands of years. Used traditionally for digestive complaints, blood sugar regulation, and antimicrobial properties. Mentioned in ancient Sanskrit texts as twak.
Active compounds: cinnamaldehyde, A type proanthocyanidins, eugenol, cinnamic acid, coumarin (cassia only, hepatotoxic)
Remedies using Cinnamon · Browse by body system · Check it against what you take
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.