We know (or think we know) that high blood glucose, or hyperglycemia, is linked to diabetes and obesity. But now scientists have also recently discovered a link between excess blood sugar and Alzheimer’s disease.
Researchers have established a “tipping point” link between excess blood glucose and the disease, meaning that people who eat a lot of sugar could be more likely to go on to develop Alzheimer’s. 
Omar Kassaar, a biologist at the University of Bath in the U.K., said in a press release:
“Excess sugar is well-known to be bad for us when it comes to diabetes and obesity. But this potential link with Alzheimer’s disease is yet another reason that we should be controlling our sugar intake in our diets.” 
In the study, published on February 23, 2017 in the journal Scientific Reports, researchers looked at brain samples from people with and without Alzheimer’s disease, which is caused by an abnormal buildup of protein tangles between the brain’s nerve cells. This buildup progressively damages the brain and causes severe cognitive decline.
The team used a sensitive technique to detect the process of glycation. The researchers noted that in the early stages of Alzheimer’s, glycation damages an enzyme called macrophage migration inhibitory factor (MIF). MIF plays a role in insulin regulation and immune response. When MIF is inhibited or reduced, it appears to make it harder for the brain cell to respond to the accumulation of abnormal proteins. 
The researchers discovered that as Alzheimer’s progresses, glycation of the MIF enzyme increases. This, the team believes, is the “tipping point” in disease progression.
Jean van den Elsen, a co-author and professor in the University of Bath’s biology and biochemistry department, said in a press release:
“Normally MIF would be part of the immune response to the build-up of abnormal proteins in the brain. We think that because sugar damage reduces some MIF functions and completely inhibits others that this could be a tipping point that allows Alzheimer’s to develop.” 
The next step for researchers is to determine whether they can detect similar changes in the blood.
 Fox News