Testosterone

• multiplicate the nervous fibers 
• avoid the sclerosis of the cerebral arteries
• avoid the amyloid peptide production (see below) and consequently its deposit into the brain

The following study demonstrate the dramatic decrease of testosterone and estradiol in the blood of men as a consequence of a chemical castration :

Chemical andropause and amyloid-beta peptide.
JAMA. 2001 May 2;285(17):2195-6.

Chemical Andropause and Amyloid- Peptide
(JAMA. 2001;285:2195-2196)

 
Figure. Plasma Concentrations of Amyloid- Peptide (A), Testosterone, and 17-Estradiol From 6 Men With Adenocarcinoma of the Prostate
 
Plasma concentrations were determined serially on samples drawn 1 week prior to initiating treatment with flutamide and leuprorelin acetate and on weeks 4, 12, and 24.

The testosterone production decreases with age in man and woman

• The prevention of Alzheimer 's disease must begin immediately when the decrease in male hormones production is detected
• even if there exists other pathological pathways to explain the pathology
• number of pathological consequences could be the result from biochemical anomalies resulting from a simple cause : the dramatic decrease of  androgens production in man as in woman after forty.