- Research published this week in the journal Neurology suggests that the ground for strong thinking and memory skills among older adults may be laid decades earlier, in childhood.
- This study found that even before participants showed signs of Alzheimer’s disease, the presence of amyloid-beta plaques was linked to lower scores on cognitive tests.
- Higher educational attainment was also linked to higher cognitive test scores around age 70, even after controlling for childhood test results.
In 2014, up to 5 millionTrusted Source Americans had Alzheimer’s disease. Over the next 4 decades, that number is expected to nearly triple to 14 million.
Many more adults will develop milder forms of cognitive decline and impairment as they get older.
Understanding the risk factors for cognitive challenges in later life may help experts develop strategies for promoting healthy aging.
New research published this week in the journal Neurology suggests that the ground for strong thinking and memory skills among older adults may be laid decades earlier, in childhood.
When scientists from University College London (UCL) in the United Kingdom followed 502 study participants over the course of more than 60 years, they found that people who scored in the top 25 percent in cognitive tests at age 8 were likely to remain in the top 25 percent at age 70.
“This study would suggest that our cognitive skills are fairly stable over our lifetime, assuming that there’s nothing else going on that causes brain damage or brain injury,” Dr. Doug Scharre, director of the Center for Cognitive and Memory Disorders at The Ohio State Wexner Medical Center, told Healthline.
“In other words, if you’re pretty smart at age 8, you’re probably going to be pretty smart at age 70,” he said.
This research was conducted as part of a much larger study, known as the National Survey of Health and Development (NSHD).
The NSHD is a cohort study of 5,362 people who were born during the same week in March 1946 in mainland Britain. The participants have taken part in dozens of surveys and tests since they were born, providing a large body of data for scientists to work with.
The authors of this substudy recruited 502 participants from the NSHD sample and asked them to complete multiple cognitive tests between the time they were 69 and 71 years old. Those tests included an adapted version of the Preclinical Alzheimer Cognitive Composite (PACC).
Among participants who were found to be cognitively normal, 406 underwent brain scans to check for amyloid-beta plaques. This is a type of abnormal protein deposit that’s associated with the development of Alzheimer’s disease.
When the researchers compared the average results of cognitive testing at age 8 to the results around age 70, they found that participants’ thinking skills in childhood were predictive of their thinking and memory skills in later life.
But childhood test scores weren’t the only factor that was associated with cognitive performance later on.
Higher educational attainment was also linked to higher cognitive test scores around age 70, even after controlling for childhood test results.
Participants who obtained a college degree scored about 16 percent higher on average than those who left school before age 16.
Participants who had worked professional jobs in their 50s also scored slightly higher on memory tests than those who had worked manual jobs.
According to Rebecca Edelmayer, PhD, director of scientific engagement at the Alzheimer’s Association, these results aren’t altogether surprising.
“I think what we’ve learned [from this study and others] is that we should be paying attention to how we can reduce individuals’ risk over their life course by making sure that education is happening across the lifespan.
“There’s many things that go into [learning and education], including not only genetic predisposition for cognition, but also socioeconomic factors, stresses in life, access to health, and all of these things that could potentially play a role in whether or not you’re receiving quality education,” Edelmayer said.
While your cognitive development in early childhood and your educational attainment and socioeconomic status may affect how you age, brain injuries and illness can also influence your cognitive abilities in later life.
For example, the development of amyloid plaques in the brain may contribute to the development of Alzheimer’s disease in people of diverse backgrounds.
This study found that even before participants showed signs of Alzheimer’s disease, the presence of amyloid-beta plaques was linked to lower scores on cognitive tests.
None of the participants who underwent brain scans were showing signs of Alzheimer’s disease, but 18.3 percent of them tested positive for amyloid-beta plaques. Those who tested positive for these plaques attained lower average PACC scores than those who tested negative for the plaques.
This suggests that changes in an individual’s PACC scores over time might be used to predict their risk for developing Alzheimer’s disease.
“The PACC test that they used is a very sensitive cognitive test, and the researchers noticed that [the average PACC scores were] slightly worse in those that had amyloid plaques,” Scharre said.
“So, maybe if we test an individual at age 65 and then again at age 70, it’s possible that a change in test score might predict those that are beginning to develop amyloid plaques, and that might be predictive of future Alzheimer’s disease,” he said.