Is sugar really toxic?

Yes, especially long. Sugar is the primary fuel for the functions of your cells, but that level is highly regulated. So, when level stays above the "normal range" as it categorized as hyperglycemia and later diabetes. Sugar level is higher after meals, but body normally brings it back down. Long term high bs is "toxic to cells" and causes many problems, thus so important to control dm. Consult your doc.. Good luck.