Use it or Lose it
The answer turns out to be quite simple. We just have to engage our brains in stimulating activities. A review of 22 studies concluded: "This study demonstrates robust evidence that complex patterns of mental activity in the early, mid, and late-life stages is associated with a significant reduction in dementia incidence." Anything that is mentally stimulating will fit the bill, such as intellectually demanding occupations and leisure activities -- even a good social life. Physical activity might also build cognitive reserve, but this is still under review because most physical activities also involve mental and social stimulation. Maybe the most interesting finding was in one study that concluded the strongest effect comes from combining mental, social, and physical activities. The reason we’re able to build cognitive reserve is that brain networks have the ability to change and adapt. This plasticity enables the brain to modulate its structure and function in response to the demands put upon it. So when faced with the challenges of stress, toxins, surgery or simply the changes that come with aging, the brain will be able to find its way around the negative factors and continue to function well.Mid-Life Hobbies Reduce Dementia Risk
In the most recent study to investigate cognitive reserve, published in the journal Neurobiology of Aging in July, researchers from Cambridge University used MRI scans to measure gray matter volume in 205 people between the ages of 66 and 88. The seniors also took an IQ test and filled out a questionnaire about their physical, social and intellectual leisure activities before they retired. The researchers discovered that in midlife, the hobbies the volunteers engaged in contributed to a better IQ later in life, regardless of the number of years of education they attained or their occupation. Also, those who spent more time in leisure activities depended less on brain size to sustain their IQ. Dr. Dennis Chan, the neuroscientist who led the study, said, “We’re quite excited by our findings. Everyone can do this [increase their activity levels] — it doesn’t matter what you do for work or where you are. Activities like chatting to family or reading are free...all these activities are good for you. "We start with the same hardware — our brains — but the things we do can make it more robust. This is the phenomenon called cognitive reserve ... There’s no one-size-fits-all approach, but the message is, what you do between the ages of 35 and 65 may affect your risk of dementia post 65."Prevents Brain Pathology
Cognitive reserve explains why brain function can be maintained in the face of pathological changes, but it might go even further and actually prevent those changes from occurring in the first place. Researchers from the University of Wisconsin, Madison found age-related biomarkers of Alzheimer's in the cerebrospinal fluid were diminished in those with a greater cognitive reserve as measured by the number of years of education. So it's possible that a higher reserve could prevent pathological changes from happening. One of the early proponents of the theory of cognitive reserve is Yaakov Stern, Professor of Neuropsychology at Columbia University, New York. He said up to this point he had only considered the idea of such reserves as boosting resistance, not preventing brain pathology. But the results of the Madison study raise the interesting possibility, he believes, that people with higher reserves might prevent dementia altogether.