Cinnamon holds a genuinely unusual distinction: for most of recorded history it was one of the most valuable traded substances on earth, at times worth more by weight than gold. Ancient Egyptians used it in embalming and religious offerings, importing it via Arab traders who deliberately obscured its true Sri Lankan and Southeast Asian origins with elaborate, fabricated stories — including tales of giant birds guarding cinnamon nests — to protect their trade monopoly for centuries.
Chinese medical texts document cinnamon use as early as 2700 BCE, valued for warming the body and supporting circulation, a use that persists in Traditional Chinese Medicine today. Its extraordinary value later drove real geopolitical consequences: Portuguese and then Dutch colonial forces fought directly over control of Ceylon (Sri Lanka) specifically for its cinnamon monopoly, making it one of the few spices whose trade history is inseparable from colonial conquest. Worth noting for anyone buying it today: most cinnamon sold in supermarkets worldwide is the cheaper Cassia variety, not true Ceylon cinnamon — a distinction that also matters for safety.
Cinnamon has one of the larger and more consistent evidence bases among spices, concentrated heavily on blood sugar management in type 2 diabetes. A 2023 dose-response meta-analysis pooling 24 randomized controlled trials found cinnamon supplementation produced a statistically significant reduction in fasting blood sugar, insulin resistance markers, and HbA1c (long-term blood sugar control) compared to control groups. A separate, larger 2025 meta-analysis covering 28 trials and over 3,000 patients with type 2 diabetes reached similar conclusions on fasting glucose and post-meal glucose.
The honest caveat: not every meta-analysis agrees on every marker. One meta-analysis found significant improvements in triglycerides and LDL cholesterol but no significant change in fasting glucose or HbA1c, while another found glucose benefits but no significant lipid or inflammatory changes. Researchers consistently attribute this inconsistency to major differences in cinnamon species, dose, and trial duration between studies — Cassia and Ceylon cinnamon are not interchangeable in these trials. Taken together, cinnamon has real, replicated signal for blood sugar support, but exactly which markers improve and by how much still varies study to study.
Dried bark ground to powder or used as whole rolled quills, steeped in hot water as tea, or added to food and drink. Ceylon cinnamon's bark is thin and easily crumbled into multi-layered "quills"; Cassia bark is thicker and rolls into a single-layer scroll — a visible way to tell them apart.