Reading and writing through old age might slow the rate of dementia, a new study finds.

Nearly 300 older adults were given annual memory and thinking tests for about six years, or up until their deaths, which averaged out at around age 89. The adults also answered questions about whether they read, wrote and participated in other mentally stimulating activities during childhood, adolescence, middle age and at their current age.

Once they died, researchers examined their brains for physical signs of dementia, such as lesions, plaques and tangles.  Participants who stimulated their minds throughout showed less tangible signs of memory decline than those who did not, the researchers found.

Compared with people with average activity, the rate of decline was reduced by 32% in people with frequent mental activity late in life, whereas those with infrequent activity experienced a decline 48% faster.