Sleep and Dementia: A Version of Pascal’s Wager

My guess is that poor sleep, over months and years, increases your risk of dementia, most commonly AD (Alzheimer’s Disease). I think of a night of poor sleep as a blow to the head, and its effects are cumulative over a lifetime. Remember how boxers and football players accumulate tiny injuries and micro tears of brain tissue: dementia pugilistica and traumatic encephalopathy.

Is my guess reasonable?  Is there a plausible rationale for the hypothesis that poor sleep increases risk for dementia (the state of chronic or permanent loss of memory and other cognitive functions)?  Consider the following:

1. The glymphatic clearance system which drains metabolic garbage  from the brain is enlarged and more active during sleep. Lack of appropriate sleep may reduce emptying and promote accumulation of toxic material.
2. If a major function of sleep is to reset brain synapses to prepare for the next day’s input (SHY Hypothesis), then lack of sleep may overload synapses, leading to damage.
3. Several studies studies find a retrospective link between dementia and benzodiazepine use (Xanax, Valium, etc.) and perhaps Z-drug use as well. It is hard to pin down cause and effect from a study looking backwards. Possibly the people using these medications have worse sleep than non users. Sleeplessness may be the hidden link.

It seems to me a reasonable bet that poor sleep is tied to dementia. Remember Pascal’s Wager:  the French mathematician and philosopher decided that choosing to believe in God was a good bet. If true, it paid off well (Heaven) and had little downside risk. The bet against God, if false, had a huge downside.

Dr. Ross’ Wager: believe that better sleep reduces risk for brain damage. This would also have collateral benefits such as that good restful feeling, improved focus and alertness, reduced occurrence of depression, hypertension, obesity, etc.  Your brain circuits work better with adequate sleep.

Seems a good bet.