i have been loosely following dr. bernstein's diet for about 10 months. My latest A1c was 5.2 and my dr. thought that was too low. He said recent studies have shown that too tight control or too low a A1c is as bad heart wise as a high A1c. That the benefit/risk of blood glucose levels was a U shaped curve where the problems associated with high A1c and low A1c climb the sides of the U. Do you know about any studies relating to this?