Cinnamon could Cause Liver Damage in Some Individuals

Kathleen Blanchard's picture

Cinnamon is a healthy addition to the diet, but researchers warn the spice could cause liver damage because of wide variances in levels of coumarin found in bark samples trees. The risk to most people is small, but noteworthy for a small number of people with coumarin sensitivity.

Scientists analyzed cinnamon samples finding high coumarin levels in some of the spice that can affect a small number of people. Both types of cinnamon, Ceylon, or true" cinnamon and cassia cinnamon contain coumarin, but it is impossible for consumers to know what they are getting in powdered form.

Coumarin in Cassia Cinnamon Highest

Scientists tested the amount of coumarin in different samplings of cinnamon and found the highest levels in cassia cinnamon powder.


The concern is that coumarin in the spice could be dangerous to certain individuals and can cause liver toxicity. The chemical that naturally occurs in plants is also an anti-coagulant and could increase risk of bleeding in a subset of individuals who inadvertently ingest too much.

Cinnamon’s popularity as a spice is second to pepper, and is supplied in sticks and powders. For the research, 91 samples of the spice sold in Germany were tested. The study confirmed cassia cinnamon contains the highest levels of coumarin and Ceylon, the lowest.

When buying cinnamon sticks, looks for Ceylon that is identifiable by the thin layers of bark rolled up in the stick. In the study, cassia cinnamon sticks were found to have 18 times more coumarin than Ceylon sticks and 63 times more coumarin in the powdered form that could lead to liver damage in sensitive individuals.