Scientists have pinpointed long-term factors that may predict who keeps their cognitive health into late age, including who will avoid brain amyloid plaques linked to dementia. 

The study followed 100 elderly adults for up to 14 years. Participants were all cognitively healthy at first, and had biannual brain imaging and annual cognitive evaluations. By the time of their last screenings, the mean participant age was 92.

Investigators found that those with better scores on thinking and memory tests at the study’s start were less likely than their peers to develop cognitive problems later. This was true even for participants who had amyloid plaques in their brains, reported Beth E. Snitz, Ph.D., and colleagues. The finding supports the theory that building cognitive reserve through lifelong learning and experiences is a buffer against brain changes, they said.

People who experienced an increase in amyloid plaques, meanwhile, were more likely to have high pulse pressure, a measure of blood pressure and sign of vascular aging. 

Lifestyle factors made a difference in cognition as well. Lifetime non-smokers were 10 times more likely to maintain cognitive health than smokers, even when they had plaques. Participant engagement in paid work and life satisfaction were also tied to better long-term memory and thinking abilities.

Outcomes were also influenced by the APOE gene, a relatively uncommon gene tied to decreased Alzheimer’s risk. In the current study, the few people who had the gene were six times less likely to develop plaques in late age than those without the gene.

“With more and more people living into their 90s and even 100s, it’s increasingly important that we be able to understand and predict the factors that help people preserve their thinking skills,” said Snitz, a neuropsychologist at the University of Pittsburgh, Pennsylvania. Changes made during the younger years may help improve the chances of extended cognitive resilience, she concluded.

The study was published in the journal Neurology.