The connective tissue density you are born with depends on the diet of your forebears and how soon they displaced real nutrition of primitive diets with the foods of modern commerce, i.e. refined sugar and flour.
-Read Weston A Price.
You can measure your own connective tissue density by looking closely at your eye in the mirror. The iris is composed of strands. If the strands are straight and close together then you have good connective tissue density. If they are curvy and separated you have poor connective tissue density.
If you have poor connective tissue density you are more prone to brain injury.
-Find a good iridologist.
If you get brain injury it is from concussive force resulting in scarring which reduces blood flow especially in the frontal lobe. There is a treatment called hemoencephalography. The best device for this would be an HEG nIR device.
-Find the article titled Former Broncos Seek Concussion Relief Through Neurofeedback
Some incredibly smart genius will google all these ideas with the word "quack" and try to wet blanket the whole thing. Everything is he-said she-said on the internet. Just explore for yourself. FWIW I vouch for all 3 from personal experience.
-Don't let him deter you
End of line.