Coumarin is a naturally occurring volatile oil (benzo-α-pyrone), found in many plants, e.g. cassia, cinnamon, tonka beans, vanilla and woodruff. Coumarin gives that pleasing and heady cinnamon aroma – a direct, sweet, fresh hay character. It was first isolated in tonka beans in the 1820s and took its name from the old botanical name for tonka – Coumarouna which in turn came from the native French Guianan name for the tonka tree, kumarú.
In high doses, coumarin can cause liver damage in small group of sensitive individuals. However, only some individuals are susceptible to liver issues from coumarin, and those individuals would need to exceed the Tolerable Daily Intake (TDI) for more than two weeks before liver issues might arise, then if they do occur the toxicity is reversible. EC Regulation 1334/2008 sets limits for the daily ingestion of coumarin.
This issue originally arose with a report on cassia cinnamon in 2006 by the Bundesinstitut für Risikobewertung (“BfR”), the scientific agency charged with providing scientific evidence for consumer health protection in Germany. This showed that consumption of foods containing cassia cinnamon can result in the TDI of coumarin being exceeded, because of the high levels of cassia cinnamon used in some recipes. Consequently, there has been a knock-on impact for bakers of traditional European bakery goods, e.g. cinnamon rolls (Danish pastries/kanelsnegle) and cinnamon Christmas cookies (Zimtsterne) within Europe, and people who use cinnamon to reduce their sugar intake by sprinkling it onto their cereal.
- Steenberg, A. (2015) Cinnamongate: is cinnamon safe to eat?, Axel and Sophie Steenberg's Blog, 19 July 2015, accessed 10 June 2016 
- European Union (2008) Regulation (EC) No 1334/2008 of the European Parliament and of the Council, 16 December 2008, accessed 10 June 2016 
- BfR (2012) FAQ on coumarin in cinnamon and other foods, Bundesinstitut für Risikobewertung, 27 September 2012, accessed 10 June 2016