Cinnamon Extract — The Blood Sugar Regulator
Ceylon cinnamon (Cinnamomum verum) and cassia cinnamon (Cinnamomum cassia) have been used medicinally for millennia. Modern research focuses on their insulin-sensitising properties, with multiple meta-analyses showing significant reductions in fasting glucose, HbA1c, and LDL cholesterol. The active compounds — cinnamaldehyde, cinnamic acid, and procyanidins — have multiple mechanisms relevant to metabolic health and longevity.
Mechanism of Action
Cinnamon's procyanidins activate insulin receptor tyrosine kinase and inhibit protein tyrosine phosphatase-1B (PTP1B), enhancing insulin signalling. Cinnamaldehyde activates TRPA1 channels, stimulating GLP-1 secretion. Cinnamon also inhibits alpha-glucosidase and alpha-amylase (reducing carbohydrate digestion), activates AMPK, and has anti-inflammatory effects via NF-κB inhibition.
Human Trial Evidence
A 2013 Annals of Family Medicine meta-analysis of 10 RCTs found cinnamon significantly reduced fasting plasma glucose (−24.59 mg/dL), total cholesterol (−15.60 mg/dL), and LDL (−9.42 mg/dL). A 2019 Journal of the Academy of Nutrition and Dietetics meta-analysis confirmed HbA1c reduction. Most evidence uses 1–6 g/day of cinnamon powder or standardised extract.
Dosing Protocol
500–2,000 mg/day of Ceylon cinnamon extract (standardised to 1–3% cinnamaldehyde). Ceylon cinnamon preferred over cassia (lower coumarin content). Best taken with meals. Cassia cinnamon: limit to <1 tsp/day due to coumarin content (liver toxicity risk). Effects on blood sugar seen after 4–8 weeks.
Safety & Contraindications
Ceylon cinnamon: excellent safety profile. Cassia cinnamon: contains coumarin — hepatotoxic at high doses (>1 tsp/day long-term). May cause hypoglycaemia in diabetics — monitor blood glucose. Potential interaction with anticoagulants (mild antiplatelet effect). Avoid high doses in liver disease.