Turmeric is known to help in diabetes in several ways. It is also known to help prevent it. Turmeric as a spice is very safe and millions of people take it.
So in general the answer is yes. (see turmeric benefits in diabetes).
But a word of caution – turmeric is known to decrease blood glucose levels. Hence it should be avoided with diabetic medications which treat hyperglycemia, as together they can lower glucose levels drastically.