Did you know?
In rodents, coumarin is known to cause kidney, liver and lung damage. It may even cause cancer. In humans, there are isolated incidents of similar effects.
In fact, the Tolerable Daily Intake (TDI) of coumarin used to be 0.2 mg/lb (0.5 mg/kg) of body weight. It has now been reduced to 0.05 mg/lb (0.1 mg/kg)
Cassia cinnamon, but not Ceylon, is a very rich source of coumarin. Cassia contains approximately 1% coumarin, while Ceylon contains only 0.004%, or 250 times less. This is so low that it’s often undetectable