Cassia cinnamon, the common supermarket kind, contains far more coumarin than Ceylon cinnamon. Normal cooking use is fine, but daily spoonfuls can exceed the tolerable intake set by EFSA.
The short answer¶
Coumarin is a naturally occurring fragrant compound found in several plants. It gives cassia cinnamon, tonka beans and new-mown hay part of their sweet, warm smell. At high intakes it can affect the liver in sensitive people. Cassia, which is what most "cinnamon" in British and American shops actually is, contains a lot of it; true or Ceylon cinnamon contains very little. For ordinary cooking this makes no practical difference. It matters for people who eat cinnamon in large amounts every day, for example stirring spoonfuls into porridge or taking it as a supplement.
The limit¶
In 2004 the European Food Safety Authority (EFSA) set a tolerable daily intake (TDI) of 0.1 mg of coumarin per kilogram of body weight per day, and reaffirmed it in 2008. A TDI is the amount that can be eaten every day over a lifetime without appreciable risk, and it includes a large safety margin. For a 60 kg adult it works out at 6 mg a day; for a 15 kg child, 1.5 mg.
How much is in cinnamon¶
Coumarin levels in cassia vary widely with species, origin, which part of the bark is used and how it is processed, and published measurements differ considerably. What is consistent is the scale of the difference: cassia typically contains coumarin at levels hundreds of times higher than Ceylon cinnamon, where it is often barely detectable.
Germany's Federal Institute for Risk Assessment (BfR) has noted that, at the higher levels found in cassia, a small child could exceed the TDI with a relatively small amount of cinnamon, and an adult with one or two teaspoons a day. Because content varies so much, it is safer to think in terms of "a heaped spoonful every day is a lot" than to rely on exact figures.
| Type | Botanical name | Coumarin |
|---|---|---|
| Ceylon or true cinnamon | Cinnamomum verum | Trace |
| Chinese cassia | Cinnamomum cassia | High |
| Indonesian (Korintje) cassia | Cinnamomum burmannii | High |
| Vietnamese (Saigon) cassia | Cinnamomum loureiroi | High, often highest |
💡 Telling them apart
Whole Ceylon quills are made of many thin, papery layers rolled together, like a cigar, and crumble easily. Cassia sticks are a single thick, hard layer of bark curled in from both sides. Ground, they are hard to distinguish, so check the label for "Ceylon" or Cinnamomum verum.
Regulation of foods¶
EU flavourings law, retained in Great Britain, does not allow pure coumarin to be added to food, and sets maximum coumarin levels for certain foods in which cinnamon is used, with higher limits for traditional and seasonal baked goods that list cinnamon on the label than for other fine bakery wares. Cinnamon sold as a spice is not itself subject to a limit.
These rules caused a public row in Denmark in the 2010s, when enforcement of the limits threatened the traditional cinnamon swirl, the kanelsnegl. Bakers switched to lower-coumarin cinnamon or adjusted recipes, and the Danish authorities later clarified which products counted as traditional.
In the United States, coumarin has not been permitted as a direct food additive since the 1950s, which is why tonka beans cannot legally be sold as food there, though cassia is sold freely.
Who should take care¶
- People eating cinnamon in large amounts daily, especially as a supplement. Choose Ceylon cinnamon if you want a daily spoonful.
- Children, because the TDI scales with body weight. A cinnamon bun is fine; cinnamon sugar on everything every day is worth moderating.
- Anyone with liver disease or taking medicines that affect the liver should speak to their GP or pharmacist before taking cinnamon supplements.
For everyday cooking, a cinnamon stick in a curry, a teaspoon in a crumble or a sprinkle on toast is not a concern. Coumarin sensitivity varies between people, and the TDI is deliberately conservative.
See also cinnamon, cassia, tonka-bean, mixed-spice and nutmeg-toxicity.