Education appears to protect older adults, especially women, against memory loss, say researchers, suggesting that children, especially girls, who attend school for longer will have better memory abilities in old age.

The study published in the journal Aging, Neuropsychology and Cognition, tested declarative memory in 704 older adults (58-98 years of age). Declarative memory refers to our ability to remember events, facts, and words, such as where you put your keys or the name of that new neighbour.

"Evidence suggests that girls often have better declarative memory than boys, so education may lead to greater knowledge gains in girls," said study's senior investigator Michael Ullman from Georgetown University in the US.

"Education may thus particularly benefit memory abilities in women, even years later in old age," Ullman added. Participants were shown drawings of objects and then were tested several minutes later on their memory of these objects. The findings showed that their memory performance became progressively worse with ageing.

However, more years of early-life education countered these losses, especially in women. In men, the memory gains associated with each year of education were two times larger than the losses experienced during each year of ageing. However, in women, the gains were five times larger. For example, the declarative memory abilities of an 80-year-old woman with a bachelor's degree would be as good as those of a 60-year-old woman with high school education. So, four extra years of education make up for the memory losses from 20 years of ageing.

The results suggest that girls who attend school for longer will have better memory abilities in old age. This may have implications for memory loss in Alzheimer's disease and other dementias. "Education has also been found to delay the onset of Alzheimer's disease. We believe that our findings may shed light on why this occurs," Ullman said.

"Since learning new information in declarative memory is easier if it is related to the knowledge we already have, more knowledge from more education should result in better memory abilities, even years later," said study's lead author Jana Reifegerste.

"These findings may be important, especially considering the rapidly ageing population globally. The results argue for further efforts to increase access to education," Reifegerste added.