About ten years ago I briefly worked with a brilliant man who had only recently received an Alzheimer’s diagnosis. We’ll call him Michael. Michael’s doctors were insistent that diagnosis had eluded them for a longer period than normal with Michael because of his incredible intellect. He was a prolific author of legal textbooks. Thus, wherein a regular person might lose a third of his vocabulary and be instantly diagnosable, Michael could lose about 80% of his vocabulary before people would notice he was reaching for words. His wife continuously talked about how Michael was revered in the field and was one of the greatest minds to have ever taken on authorship of law school textbooks.
His family noticed emotional and physical deficits before the diagnosis. And by the time I interacted with him, he could understand directives but forgot how to tell his body to do them. I asked him to turn over from a lying-on-back position to lying-face-down; and though he understood precisely what I said, he couldn’t remember how to turn over his body. It was incredibly sad to watch the shell of a once-great mind brought so low. And some may think it unavoidable.
However, for decades a mountain of evidence has been springing forth to show us that neural inflammation can be reduced or at least partially controlled. That is, even “unavoidable” outcomes may be delayed, and assuaged, if not reversed. Mechanistically, it makes a ton of sense, since we can all fathom receptor up-regulation and down-regulation.
For example, as a person takes caffeine, does she become more resistant (tolerant) to its signal or less resistant? If a person drinks alcohol, do his receptors require the same amount or more to invoke the same response? Likewise with stress and glucose, persistent elevations will numb receptors. As receptors become degraded and corroded, it becomes increasingly difficult to get energy into the cells whose receptors are worsening. When those cells are brain cells, do the math.
Again, recently, researchers took on this subject, except from an epidemiological data gathering: https://www.ucl.ac.uk/.../prediabetes-may-be-linked-worse... . I don’t tend to like these types of studies, because they ignore mechanisms and attempt to link causes through statistical indices. That said, a study of this nature does contain the power to cast doubt on supposed correlations, if they uncover an unexpected statistical relationship. In this case, they did not cast doubt. Findings were consistent with our expectations on how unregulated glucose injures tissue. Those with uncontrolled sugars do have a higher tendency toward brain deterioration.
And perhaps, if you too have an intellectual starting point as meteoric as Michael’s, it won’t be overtly evident in your 40s or 50s or even early 60s. But all that means is if you wait until reality is no longer deniable you will have less time to face the problem. In his case, once the symptoms were undeniable, he became wholly incapacitated in the course of a couple years. Since the brain, like all organs, can regenerate to a certain extent, if you take on the problem now, your prospects will be a lot brighter.