If you're eating a lot of added sugar, then you can basically be on the high end of the normal range for blood glucose levels. So, you're within the normal range, but on the higher end ... There are studies showing that people on the high end of the normal range have increased atrophy in the hippocampus part of their brain—that's involved in learning and memory—and they have higher atrophy in the amygdala part of the brain—that's involved in emotional regulation—compared to people on the lower ... There's also other studies showing that higher blood glucose levels are associated with 54% increased risk for vascular dementia.