I know a man in his 50s who had chlamydia in his 20s. His father died of Alzheimer’s. Should I suggest he be tested for residual chlamydia, and get the APO-e4 gene test? Also should the woman he knew 30 years ago be worried and contacted?
I would get them, under those mentioned conditions, myself. We talk to reducing blood sugar and insulin to prevent dementia and Alzheimer's, but if we also have another avenue that could lead to such a condition and have it stopped early, that is a win.
Do note some studies are showing that Alzheimer's could have some early warnings that we don't see for 20 years. It might not be completely reversible, but it could be slowed for its fuller onset.