NOTTINGHAM, United Kingdom — Growing older has long been associated with a decline in mental sharpness, but a new study suggests that this may be changing. Prior research warns that the number of people with dementia will triple by 2050. Is that prediction overblown? Contrary to popular belief, new data reveals that today’s older adults are actually more cognitively capable than their predecessors and that the gap in cognitive ability between the young and old is shrinking over time.
The study, conducted by Stephen P. Badham of Nottingham Trent University and published in the journal Developmental Review, takes a comprehensive look at trends in cognitive aging through three different lenses. By analyzing a wide range of existing research, historical data, and the results of new experiments, Badham paints a compelling picture of a shifting landscape in how our minds age.
First, Badham conducted a meta-analysis — essentially, a study of studies — looking at research comparing the cognitive abilities of older adults born in different time periods. Across the board, he found that those born later tended to outperform those born earlier on cognitive tests. What’s more, the gap in performance grew larger as the birth years of the groups being compared grew further apart. This suggests a steady, continuous improvement in cognitive function among older adults over time.
“As older adults are performing better in general than previous generations, it may be necessary to revise definitions of dementia that depend on an individuals’ expected level of ability,” Badham says in a report by The Conversation.
So, is this trend driven by improvements among the elderly, or might younger adults actually be getting worse? To find out, Badham turned to a second meta-analysis, this time focusing on studies comparing young and old participants at a single point in time. The results were striking: the typical difference in cognitive performance between young and old has been getting smaller in more recent studies. This finding held true across a diverse array of cognitive tasks and research designs.
Finally, to rule out any quirks or inconsistencies in the existing literature, Badham analyzed raw data from his own lab, where he tested the cognitive abilities of young and older adults using the same methods over a seven-year period. The results mirrored those of the meta-analyses: while older adults’ performance improved markedly over time, the younger group showed little change. The gap between young and old was closing, and it was the older folks who were catching up.
“The decline an individual might expect to experience as they become older is smaller than originally thought. In other words, we can expect to be more cognitively able than our grandparents were when we reach their age,” Badham says in a media release.
So, what’s behind this unexpected trend? Badham points to a combination of factors that have been improving over generations. Education is a big one – as access to schooling has expanded and the average level of educational attainment has risen, each successive generation has enjoyed a cognitive boost. Advances in healthcare, nutrition, and general standard of living likely play a role, too. Even things like more mentally stimulating jobs and hobbies and a reduction in smoking may be contributing to healthier, more resilient brains in old age.
Interestingly, these findings dovetail with recent research showing a decrease in rates of dementia and age-related diseases like stroke and heart failure. It seems that not only are our minds staying sharper longer, but our bodies are also aging better. Some researchers have suggested that rising life expectancy itself might be a factor, as those who live longer may tend to be the most cognitively and physically robust.
Of course, aging is still no cakewalk for the brain. Cognitive decline remains a real phenomenon, and diseases like Alzheimer’s continue to take a heavy toll. But what this research suggests is that the baseline – what we consider “normal” cognitive aging – may be shifting. The average 75-year-old today, it seems, would likely run mental circles around the average 75-year-old of decades past.
This has important implications for how we think about and study the aging mind. Researchers may need to update their expectations and reexamine long-held assumptions. Benchmarks for what constitutes “impairment” in older adults may need to be periodically recalibrated. And with the oldest segment of the population growing rapidly, policymakers and healthcare systems will need to adapt to a new reality in which advanced age isn’t necessarily synonymous with cognitive decline.
As older adults are performing better in general than previous generations, it may be necessary to revise definitions of dementia that depend on an individuals’ expected level of ability. This is because dementia is defined as cognitive ability that is below normal and the current results suggest that as healthy older adults become more cognitively able, it may be time to revise our definition of normal when diagnosing dementia.
“Given the trend of lower dementia incidence over time it is crucial to establish if healthy cognitive aging is also changing over time,” Badham writes in his paper, “so that dementia diagnosis thresholds accurately correspond to pathological cognitive decline in excess of decline due to healthy aging.”
For the average person, these findings offer a heartening message. While aging will always involve challenges, the specter of inevitable mental deterioration may not loom quite as large as it once did. With continual advancements in education, health, and quality of life, we may all have a better shot at staying sharp well into our golden years. The secret to a youthful mind, it turns out, may lie not in any individual anti-aging trick but in the steady march of societal progress. So, while we may not have found the fountain of youth just yet, we seem to be getting better at navigating the passage of time.