Reading difficulties in childhood are linked to poorer cognitive skills in older age and a greater likelihood of registering scores indicative of dementia risk, suggests research published online in the Journal of Epidemiology & Community Health.
Educational attainment only partially affected these associations, which highlight the long-lasting effects of childhood reading problems on cognitive ability across the life course, say the researchers.
Reading problems are relatively common, with estimates suggesting that 2–15% of people are affected.
Previously published research shows that reading problems persist through to midlife and can be associated with lower income, poorer self-esteem, and higher rates of mental ill health.
But there’s not much research on the potential longer term impact of reading difficulties in childhood on cognitive ageing across the life course.
In a bid to plug this knowledge gap, the researchers drew on information from the long term population-based MRC National Survey of Health and Development, which involves 5362 people born in England, Scotland and Wales during one week of 1946.
Reading problems were formally measured at the age of 11 in 4281 children, with verbal memory and processing speeds subsequently measured at the ages of 43, 53, 60–64 and 69.
When they were 69, participants also took the Addenbrooke’s Cognitive Exam (ACE III), which is used to pick up cognitive impairment and dementia risk.
Potentially influential factors, such as sex, educational attainment, socioeconomic position in childhood and adulthood, and mental health were also accounted for.
In all, complete information on childhood reading ability, all cognitive measures, and the ACE 111 score was available for 1051 people.
After adjusting fully for potentially influential factors, the analysis revealed that reading problems at age 11 were significantly associated with poorer memory at the various time points, although not with the rate of decline from age 43 to 69.
Reading problems weren’t significantly associated with trajectories of processing speed.
But they were significantly associated with lower scores on all ACE-III domains: fluency; language; attention; memory; and visuospatial skills, as well as the total score.
Higher reading scores at the age of 11 were significantly associated with better cognitive function in all domains by the age of 69.
These associations were only partially altered by educational attainment. After factoring in cognitive ability in childhood, reading problems were significantly associated with poorer scores in verbal cognitive functions (fluency, language and memory), but not non-verbal functions (attention and visuospatial) by the age of 69.
“Specifically, childhood reading problems are associated with lower education, which is in turn associated with poorer cognitive function at age 69,” explain the researchers.
“However, even when including the indirect pathway through education in the model, direct effects between childhood reading problems and cognitive function at age 69 remained statistically significant.”
This is an observational study, and as such, can’t establish cause. And the researchers acknowledge various limitations.
Some key data were missing and people with reading problems and poorer cognitive function were more likely to drop out. Data were only available up to the age of 69, so cognitive ability in later life couldn’t be tracked.
Lower reading scores may also reflect underlying conditions, including developmental disorders, dyslexia, or autism, they point out.
Nevertheless they conclude: “These findings are important because they highlight the long-lasting effects of childhood reading problems on cognitive health across the life-course over a follow-up period of six decades.”
John, A., et al. (2021) Childhood reading problems and cognitive ageing across mid to later life. Journal of Epidemiology & Community Health. doi.org/10.1136/jech-2020-215735.