Is it true that cinnamon can help with diabetes?

Yes. Result of a study demonstrated that intake of 1, 3, or 6 g of cinnamon per day reduces serum glucose, triglyceride, LDL cholesterol, and total cholesterol in people with type 2 diabetes and suggest that the inclusion of cinnamon in the diet of people with type 2 diabetes will reduce risk factors associated with diabetes and cardiovascular diseases. Study published 2003 american diabetic associatn.
No. Several studies have been done in regards to cinnamon and control of diabetes and currently there is no definitive answer.