FYKI (For Your Kind Information)
BNatural has a list of Juices, one of which is Jamun Juice. It is said to control blood sugar. It is available in India, not sure about other countries.
The fruit Jamun - http://en.wikipedia.org/wiki/Jambul
(PS: I am not an employee or associated with this company
I would be very much interested in knowing about similar fruits and other juice products which may help in controlling blood sugar.