Our thinking skills in childhood could offer a glimpse into how our minds might work at the age of 70, according to a study spanning decades.
The research started in 1946, when 502 8-year-olds, who were born in the U.K. in the same week, took tests to measure their thinking and memory skills. The participants took cognitive tests again between the ages of 69 and 71.
The participants also had scans, including a positron emission tomography (PET) scan that detects amyloid-beta plaques in the brain. These sticky collections of protein are linked to Alzheimer’s disease.
The study, published in the journal Neurology, shows those with the highest test scores in childhood were more likely to have high scores later in life. Kids in the top 25 percent had a greater chance of being in that same quartile at 70.
Educational attainment and socioeconomic status also appeared to make a difference. Those who were college-educated scored around 16 percent better in tests than those who left school before they hit 16. Participants who had a white-collar job were able to remember, on average, 12 details from a short story, versus 11 if they had a manual job. Overall, women did better than men when their memory and thinking speed were tested.
Participants who were found to have amyloid-beta plaques in their brains, meanwhile, scored lower on cognitive tests. In one assessment where participants had to find the missing pieces in five geometric shapes, those with the plaque got 23 out of 32 problems correct, versus 25 for those without the plaques.
Dr. Jonathan M. Schott of University College London commented: “Finding these predictors is important because if we can understand what influences an individual’s cognitive performance in later life, we can determine which aspects might be modifiable by education or lifestyle changes like exercise, diet or sleep, which may, in turn, slow the development of cognitive decline.
“Our study found that small differences in thinking and memory associated with amyloid plaques in the brain are detectable in older adults even at an age when those who are destined to develop dementia are still likely to be many years away from having symptoms.”
Earlier this year, Schott and his team published a separate study in the journal The Lancet Neurology that showed having high blood pressure in a person’s mid-30s was linked to higher levels of blood vessel damage in the brain, as well as shrinkage of the organ.
Professor Tara Spires-Jones from the UK Dementia Research Institute at the University of Edinburgh, who did not work on the new study, told Newsweek the findings add to other studies that suggest our genetics, as well as environmental factors, play a role in how we maintain our thinking skills as we age.
“However, this does not mean that all of your brain power during aging is determined during childhood,” she said. “There is good scientific evidence from this study and many others that keeping your brain and body active are likely to reduce your risk of developing Alzheimer’s disease, even as adults.”
Learning, socializing and exercise can all help, she said.
“One way this works is by building new connections between brain cells, called synapses. Synapses are the building blocks of memory, so building up a robust network of synapses, sometimes called ‘brain reserve’ is thought to be the biology behind the finding that more education is associated with a lower risk of dementia and age-related cognitive decline,” explained Spires-Jones.
Spires-Jones suggested amyloid-beta plaques might be linked with lower tests scores in the study because they build up and damage the connections between brain cells, called synapses, impairing brain function.
“Amyloid plaques are also widely thought to initiate a toxic cascade that leads to dementia in Alzheimer’s disease, including the build-up and spread of another pathology called ‘tangles,'” she said.
She said the study was “very strong” but limited because observational studies can’t explain the links that emerge, and the participants were all white so the results might not relate to other populations.
“It will be important in future work to try and understand the biological underpinnings for the associations between childhood intelligence and better cognitive ability during aging,” she said.