We are told about the major rise in "dementia" and not simply among the aged, but in younger age groups. Certainly the brain is a crucial, vulnerable and sensitive part of the body. Among other things it needs reliable and "clean" blood flow.
My concern is whether, given the shortage of time, specialists and the rest in the NHS whether the diagnosis of dementia is being made too quickly and easily in many cases. That is apart from actual and known physical injury.
There are a number of brain effects that create "fog". The list below is not in any order of number or seriousness. Also, in many cases there may be more than one interacting factors. Another is whether the effects are temporary or can become permanent.
Brain fog from chemical reactions e.g. fragrances
Diet - additives, flavourings, pesticides etc.
High sugar and starch intake
Concussion and noise over time
Acoustic effects of loud sound
Physical, blood flow, cell damage/loss/disease, age shrinkage,
Sleep problems (external noise etc.) and overwork
EMS: electro magnetic (field) sensitivity