Ceylon vs cassia: why one cinnamon is classified as a liver toxin

In a Parisian supermarket, two sticks of "cinnamon" sit on a shelf. One is pale tan, rolled like a cigar with many thin layers and brittle to break. The other is dark reddish-brown, a single thick curl, hard as wood. The first is Ceylon cinnamon (*Cinnamomum verum*). The second is cassia (*Cinnamomum cassia* or related species). The label on both often says simply "cinnamon." Under EU food law, they are not treated as the same substance.

Two species, two molecules

The distinction matters because of coumarin — a naturally occurring compound that cassia contains at high levels (roughly 2,100 to 4,400 mg/kg) and Ceylon cinnamon contains at trace levels (under 200 mg/kg, often below detection). Coumarin is hepatotoxic at sustained high doses. The European Food Safety Authority established a tolerable daily intake of 0.1 mg per kg body weight in 2008, and BfR — the German federal risk assessment institute — issued a dedicated warning in 2006 about Weihnachtsgebäck (Christmas cookies) made with cassia.

For an adult, two tablespoons of cassia powder can exceed the TDI. For a child, much less. The actual harm at holiday-level consumption is low for most people, but the regulatory asymmetry is real: cassia is sold as "cinnamon" while being classified as a risk category that Ceylon is not.

Ceylon: the original, the minority

Ceylon cinnamon is native to Sri Lanka and still cultivated almost exclusively there. The bark is harvested from four- to six-year-old coppiced shoots of *C. verum*, scraped to remove the outer cork, rolled by hand into thin quills and shade-dried. A skilled processor produces fifty to a hundred quills per day — the grading system (Alba, Continental, Mexican, Hamburg) reflects quill diameter and visible defects, with Alba being the thinnest and most expensive.

Real Ceylon is delicate, sweet, slightly citrus, and its essential oil is dominated by cinnamaldehyde (around sixty-five percent) with eugenol and linalool as supporting notes. Its colour is lighter and it is friable — a stick crumbles under finger pressure.

Cassia: the global commodity

What supermarkets sell as cinnamon is overwhelmingly cassia — grown in China, Vietnam, Indonesia. Its bark is thicker, its essential oil stronger in cinnamaldehyde (seventy to ninety percent) with much less aromatic complexity. It is cheap, heat-stable, and holds up in baking — which is why industrial kitchens use it.

Vietnamese *Cinnamomum loureiroi* (often called Saigon cinnamon) is a cassia with especially high cinnamaldehyde content, prized by bakers but also among the highest in coumarin.

How to tell them apart

Buy sticks, not powder. A Ceylon stick has multiple paper-thin layers rolled together — cut it open and you will see concentric rings like a cigar. A cassia stick is one or two thick layers curled on themselves. Ceylon is tan to light brown; cassia is reddish to dark brown. Ceylon breaks easily; cassia does not. And if the label says "Ceylon cinnamon" but the price is identical to generic cinnamon from the same brand, it almost certainly is not.