2 April 2018

Coumarin – a liver damaging toxin in cheap cinnamon.

Natural toxin

Natural toxins can as well be found in your day-to-day living environment. Ordinary food products, especially spices, may contain moderate amounts of toxins. Overall, the hot or bitter taste of fruits, leafs or seeds is an evolutionarily developed defensive expression of plants to prevent themselves from being grazed.

Cinnamon powder is a smoothly grinded bark of a tree genus Cinnamomum. The product has a particularly specific flavour and is used as a food additive in the cuisines worldwide. Besides a wide range of vitamins and minerals, aromatic cinnamaldehyde and essential oils that bring the desired scent and the taste, the bark of the tree contains various levels of coumarin – undesired hepatoxic substance causing direct damage to liver and kidneys.

Structure of Coumarin. Click image for 3D model.

The cinnamon from the tree species Cinnamomum cassia – one of the four most popular species for cinnamon production – have the highest coumarin content. One teaspoon of cassia cinnamon powder may exceed the tolerable daily intake (TDI) for humans. On the other hand, the bark of the Cinnamomum verum contains insignificant levels of coumarin1.

There are regulatory measures imposed to limit the levels of coumarin in the final food products in many countries of the world (including EU2), although they are often violated3. The regulations drive the demand of the Cinnamomum verum higher which results in its higher price. Consequently, the cheap cinnamon is more likely to be of the origin containing higher levels of coumarin. Acute effects of coumarin consumption in moderation may not be noticeable. However, complemented with other negative factors like pollution and unhealthy lifestyle, repetitive violation of tolerable daily intake of coumarin can result in accumulative liver damage and eventually contribute to cancer.

Smiles: C1=CC=C2C(=C1)C=CC(=O)O2

PubChem profile: https://pubchem.ncbi.nlm.nih.gov/compound/323#section=Top
3D model: https://chemapps.stolaf.edu/jmol/jmol.php?model=c1ccc%28cc1%29%2FC%3DC%2FC%3DO
Source of the images: www.etsy.com. Structure from Wikipedia. By Calvero. - Selfmade with ChemDraw., Public Domain, https://commons.wikimedia.org/w/index.php?curid=1873546


  1. High daily intakes of cinnamon: Health risk cannot be ruled out BfR Health Assessment No. 044/2006
  2. Regulation of the European Parliament and of the Council (EC) No 1334/2008
  3. Ballin, N.Z. et al. 2014. Coumarin content in cinnamon containing food products on the Danish market. Food Control. 38. 198–203.