Earlier quoted context omitted.
> Not only were people with two copies of the APOE4 gene much more likely to develop the biological changes that lead to Alzheimer’s disease, similar to people with the other genetic forms of the disease, they were almost assured the diagnosis: Nearly 95% of the people in the studies with two copies of the APOE4 gene had the biology of Alzheimer’s disease by the time they were 82 years old.
What percentage of people have microplastics in their body? Or have been previously infected by common childhood illness ? I’m not giving these as theories for Alzheimer’s etiology, but to show that some environmental factors are ubiquitous. Just because an environmental factor is ubiquitous—-or is ubiquitous within the frame of some sampling bias for the study—-doesn’t mean we should conclude the cause does not exis…
Unless 95% of these populations also are assured an Alzheimer's diagnosis by 82, your chosen confounding statistics may have little bearing on how closely double copies of the APOE4 gene is associated with Alzheimer's diagnoses.