Cinnamon/blood sugar study

If anyone has been following the recent news that cinnamon has been
found to lower blood sugar levels and knows anything about the study
then i have a question. they keep talking about cinnamon, but mention
all the foods that people put 'cinnamon' into. 90% of the substance
known as 'cinnamon' is, in fact, cassus bark, not the bark of the
'cinnamon' tree and while somewhat related, it is not the same thing. 
does anyone know if the study was conducted on 'cinnamon' or if it was
conducted on the substance they name in all the foods (apple pie, etc)
which is actually cassus bark?
i'm not about to go out and buy 10 kilos of cinnamon, but i'm curious
about the distinction since it is a pretty significant difference.