Testosterone and the Risk of Alzheimer's in Men

February 29, 2016

Testosterone and Risk of Alzheimer’s in Men 

 Reference: Moffat Neurology 2004

 Testosterone, all about men’s sexual health, right?   Well, that is true, and it certainly is what most men think is most important, but it’s certainly not all. And here we have today a reference study of the importance of testosterone to men’s brain health. 

 The Baltimore Longitudinal Study of men’s health started in 1958 and followed men for a mean of 19.1 years, and as long as 37 years. They had physical exams with neurological testing and blood work every other year.   Five hundred and seventy four men were included in the Alzheimer’s and testosterone study group.   That is a pretty strong sample group, for a pretty long time, so this study should have something valid to say.   After accounting for all possible confounding variables, like diabetes, cancer, smoking, age, education, hormone supplements and the like, they were left with the connection between testosterone levels and risk for Alzheimer’s.   Total testosterone and sex hormone binding globulin didn’t seem to have any connection with Alzheimer’s, but free testosterone did.  

 In fact, for every 10 nmoles increase in free testosterone, there was a 26% reduction in risk for the development of Alzheimer’s. What is free testosterone? It is the proportion of testosterone in your blood that is available for your tissue to actually use.   

Here is the explanation.   Testosterone is built from the cholesterol molecule.   Cholesterol is in the fat family, meaning it is not water soluble. If it isn’t water soluble, it can’t be moved around the body in the transport system we call blood. Blood is made of water and fat doesn’t dissolve in water. The human body has come up an ingenious method of moving it. Sex hormone binding globulin is that method. It is a protein, made in the liver, that has an internal pocket that welcomes fat; it is “hydrophilic”.   

High levels of insulin and growth hormone lower it, whereas estrogen and thyroxine raise it. It needs zinc to hold itself together in the form that binds it. These other hormones don’t need to change it much to have a big impact.   Considering that you only have about 0.1-0.3% of your total T as the “free” stuff, it only takes a small shift to alter your natural free T. There is some debate as to what a proper free T should be, but this is where the rubber meets the road. 

Many physicians consider a free T3 of 8 pg to be enough.   Well, I have come to recognize that it takes at least 35 pg to feel really good.   Many good things happen then? Remember the male brain? Now, if we apply that metric to the above study, we will find that the house of medicine will give you a clean bill of health with a free T of 8 pg. But it we raise you to 38pg, that is 3 notches of 10 pg each, and that will lower your risk of Alzheimer’s by 78%. Well, wait a minute.   

The above study shows that men who have higher free T on their own have less risk of Alzheimer’s.   That is not to say that we can prove that raising it by outside means will lower your risk. It isn’t the same thing. There may be other reasons you have high free T3 and those other reasons then account for your lower risk. And giving you T may not provide those other reasons.   

So, it’s not yet proven, and likely will never be because there is no money in it. But you will either feel better, or not care because your brain is happy. 

 www.What Will Work for Me?   I’m interested in this. I have a mother with Alzheimer’s.   I want my free Testosterone to be optimal. It’s something every man should be paying attention to.   

 Pop Quiz  

  1. For every 10 pgram increase in Testosterone, men have a 26 percent increase in risk for Alzheimer’s Disease?   T or F                           Answer:  False. You didn’t read the article. That’s backwards. DECREASE
  1. Optimal Levels of Free T3 in a man are around 8 picograms. T or F             Answer:  False. We want you at least 32 picrograms
  1. Sex Hormone Binding Globulin can muck things up by making your free T3 be all bound up? T or F                           Answer:  True
  1. You can raise SHBG by having too much estrogen. T or F                      Answer:  True
  1. You can have too much estrogen by being overweight? T or F                  Answer:  True