We have been asked about the cinnamon coumarin issue. Here are the facts.
Coumarin is a natural flavouring that occurs in many plants. It occurs in negligible concentrations in Ceylon cinnamon, but in higher concentrations in Saigon cinnamon. Back in 2006 the German health authorities observed that coumarin “can cause liver damage in a small group of particularly sensitive individuals”. This caused a stir in the German media. In a subsequent paper in October 2006 the German Federal Institute for Risk Assessment recommended a Tolerable Daily Intake (TDI) of 0.1mg coumarin per kg of bodyweight per day. This was subsequently adopted by the European Food Safety Authority. In the United States, the Food and Drug Administration commented only that there is a health risk. So there is a health risk.
How big a health risk? The UK Food Standards Agency, in a study published on 26 January 2011, did some research to compare actual coumarin intake levels to the Tolerable Daily Intake. They surveyed three groups: adults, children and South Asians (because of their more spicy diet - coumarin is also found in other curry spices such as garam masala as well as cinnamon). They concluded that, on average, adults had an average dietary exposure of 0.0018 mg per kg of body weight per day (ie less than two hundredths of the TDI), children 0.0015 (less still) and South Asians 0.022 (just over one fifth of the TDI). Even in the most extreme cases, at the 97th percentile of the South Asians group (just imagine how spicy that diet must be!) exposure was 0.076 mg per kg of body weight per day ie still well within the TDI.
How to manage this in practice? Back to the German Federal Institute for Risk Assessment who made some practical observations: “if one takes the highest coumarin levels in cinnamon biscuits supplied…then the TDI intake for infants could already be exhausted by their eating three star-shaped cinnamon biscuits….Adults would need to eat about 15 of them….” EVERY DAY! It goes on to recommend that “especially in the run up to Christmas…cinnamon biscuits should be eaten in moderation….”
Easy on those biscuits, then.