(Healthline) – 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.
Following participants over time
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.