As mentioned above, the Chinese (Cassia) cinnamon may create health problems in longer use. But, some cross arguments are there.
Cassia contains 1200 times more coumarin than Ceylon cinnamon. It means Ceylon cinnamon is 1200 more times safer than Cassia cinnamon.
High Blood Pressure, High Cholesterol
I use cinnamon (Chinese) and honey in a natural medicine protocol to treat high Blood pressure and High cholesterol level. It is part of a 35 day detox prog and I have a one hundred percent success rate. At the end of the period, every patient treated has been within the stated NORMAL levels. This includes blood sugar also. But I use Chinese cinnamon and only this.... as I was recommend to me by a former herbalist from Malaysia.