I had a "PNS/ Physician Nutrition Specialist" explain it to me like this, you can't eat enough bread for it to alter your A1C, it's either a combination of many things you're eating or it's hereditary, plain and simple.
I eat bread damn near as often as I'd like now, but try to watch my every day meal preparations.
Talk with a PNS, not a cardiologist or gen practitioner, they don't spend anywhere near enough time in school learning about nutrition to be preaching it like the gospil, like most do, it was life changing for my family.
Good luck.
Dan.