For a study published in 2013, a team led by Robert Wilson at the Rush University Medical Center in Chicago enrolled three hundred elderly people and tested their thinking and memory skills each year. The participants were also asked about how often they read, wrote, and engaged in other cognitively demanding activities, not just currently, but in childhood and middle age. Following each participant’s death, their brain was examined for evidence of dementia. It was discovered that, after taking into account the physical effects of dementia on their brains, the subjects who made a lifelong habit of a lot of reading and writing slowed their rate of mental decline by a third compared to those who did only an average amount of those things.
On the other hand, people who rarely read or wrote experienced a decline that was a staggering 48 percent faster compared to the average participants.