Brain reserve, otherwise known as 'cerebral' or 'cognitive reserve' is the theory that our intellectual ability, can (but not exclusively) be represented by our education and occupational functioning in life may shield us in some way from dementia or neurodegenerative disease. It is a concept of brain protection and resilience. We now know that the brain is a dynamic organ that can change over time with some processes of repair or regeneration and some of decline or disease, and that different brains alter differently.
Whilst the concept of cerebral reserve may seem intuitive or plausible, it remains unproven. In part, this may be due to the complexities of our lives and cognitive make-up that make devising scientific studies difficult, and in part the length of time required to study such diseases. There are likely genetic, as well as environmental, factors which contribute.
What we do understand is that whilst age is the major risk factor for dementia there are ways we can reduce our risk, even slightly, with hope to enjoy health in our older years. This includes avoiding smoking, diabetes, head injury, treating depression, avoiding excessive alcohol and maintaining a healthy lifestyle with exercise, social activity and a balanced diet. This is likely to hold true for those with or without good brain reserve. As technology improves we may be able to obtain a better 'window on the brain', understand how some brains age better than others, and hope for better therapies in dementia.