Read this article about traumatic brain injuries (TBI), which confirms that the more a person works with his/her brain prior to a brain injury, the greater the chance that person can come back successfully from the injury. Brain training can actually make all the difference in a full or near-full recovery from a TBI.
Training one’s brain either through schooling or other activities appears to build Brain Reserve or Cognitive Reserve that seems to protect the brain from developing or exhibiting Alzheimer’s symptoms.
Just how does this work?
“One idea (called Brain Reserve by researchers) postulates that some individuals have a greater number of neurons and synapses, and that somehow those extra structures provide a level of protection. In a sense, we have more ‘hardware,’ providing a passive protection against the attacks of Alzheimer’s. The other theory (called Cognitive Reserve) emphasizes the building of new capabilities, how people can perform tasks better through practice, and how these skills become so well learned that they are not too easy to unlearn. Like developing new and refined ‘software.'” ~ Dr. Yaakov Stern
The more people strengthen their brains at any stage in life, the better off they are.