I've had a look back at some (not all) of the references to Turmeric as suggested and I've noticed that a high percentage of the references are to cooking with it or taking capsules/tabs.
I came to hear of it about 4 years ago through the BBC prog. "Trust Me I'm A Doctor". In that Michael Mosley goes to pains to make it clear that the tests that they did for the program showed that the best results were found in terms of lowering BG, when one teaspoon full of ground Turmeric was taken with one teaspoon full of ground Black Pepper each day without cooking. He suggested taking it in a cold dip, shake, drink (not hot or boiled) or mixed into other cold food. For anyone who is interested I believe that the programs are still available on the BBC I Player.
Personally, I take it in a variety of other cold foods depending on how I feel, but if you don't get the right mix the Pepper can rather "focus your attention" as it can be a bit HOT.
Also like some others have mentioned, Turmeric does have the effect of thinning your blood, which I discovered when I used to take Asprin each day and got a small cut that wouldn't heal. I stopped the Turmeric and hey presto it healed. I then opted to stop the Asprin and continue with the Turmeric and I'm glad that I did.