How does Alzheimer's disease develop?

There are multiple biochemical processes associated with Alzheimer’s disease.

1.Increased levels of beta-amyloid

2.Increased beta-secretase activity (beta-secretase is an enzyme that cuts the amyloid precursor protein (APP) in such a way as to make beta-amyloid)

3.Decreased alpha-secretase activity (alpha-secretase is an enzyme that cuts APP in such a way that it can no longer make beta-amyloid)

4.Decreased neprilysin activity (neprilysin is an enzyme that breaks down beta-amyloid, whether in monomer form or oligomer form (such as plaque)

5.Increased 42/40 ratio of beta-amyloid (42 beta-amyloid is a main component of plaque)

6.Increased hyper phosphorylation tau protein (this protein makes up the tangles that kills neurons)

7.Decreased blood flow to the brain

8.Decreased brain cell glucose metabolism

Interestingly enough, testosterone reverses all of the above biochemical processes. A 19 year study in men showed that there was a strong correlation between low free testosterone and the risk of developing Alzheimer’s, with the researchers being able to predict who was going to develop Alzheimer’s up to 10 years in advance of any symptoms appearing. See: Free testosterone and risk for Alzheimer disease in older men.

In my opinion, the main cause of Alzheimer’s in both men and women is the decrease in their hormone levels as they age. Of course, genetics and diet can also play a role.

Reference: Edward Friedman