Numerous studies have indicated that educational attainment may correlate with improved health and socioeconomic outcomes, but a group of European researchers found that university attendance does not appear to stave off cognitive decline.

The findings, published April 26 in Proceedings of the National Academy of Sciences, suggest that, although expanding access to higher education may improve citizens' lives in myriad ways, it may not slow down the aging process within the brain, adding to a longstanding debate in the field.

Researchers from the University of Oslo, Umeå University and other European institutions analyzed structural magnetic resonance imaging data from the UK Biobank and Lifebrain, two massive collections of longitudinal data that are intended to track long-term genetic and environmental factors that contribute to various diseases. The study included a total of 4,422 observations of more than 2,000 participants. Scientists focused specifically on the cortical mantle and hippocampus, two areas of the brain that often show reductions in volume as people age. 

"These regions show substantial changes in normal aging, but also in Alzheimer's disease," Anders Fjell, a professor of cognitive psychology at the University of Oslo and a co-lead author on the paper, told The Academic Times. "In addition, [these regions] are critical for important cognitive functions, especially episodic memory, which also show age-related changes.​"

The results indicated that those with and without college education experienced nearly identical rates of cognitive decline as they aged. However, people who'd attended a university showed moderately higher brain volume in the regions that were tested, indicating that these individuals could possess what the authors called a "passive" reserve — a relative boost in cognition earlier in life that could translate to a slightly improved starting point as their brains begin to age. "And with a higher starting level, a person can probably cope with more decline before the level of function is too low," Fjell added.

The researchers cautioned that further studies will need to determine whether higher education itself, genetic factors or unknown environmental contributions led to the apparent correlation between higher education and increased brain volume.

Previous studies that suggested education may protect against cognitive aging took a cross-sectional approach, which made it difficult to ascertain whether secondary factors were also contributing to improved cognition in older age, the researchers said. In contrast, the present study used longitudinal data, which tracked participants' brain changes over time to better isolate whether educational level, in particular, affected cognitive ability. 

Besides educational factors, one's work environment may also contribute to long-term cognitive development and performance. Those who experienced greater degrees of self-direction and the freedom to innovate throughout their careers showed higher levels of cognition across most categories, demonstrating "less age-related decline in inductive reasoning, word fluency, and verbal meaning," according to one 2019 longitudinal study.

Other investigators have considered the controversial "fadeout effect," positing that children who experience boosts in cognitive ability in early age due to educational programs may sometimes revert back to earlier levels of cognition once those interventions are no longer present in their environment.

Across the wider population, regardless of educational level, more recently born groups of individuals tend to perform better on cognitive tasks compared to groups born longer ago, but the underlying mechanisms that cause this disparity are still a mystery. This phenomenon, known as the Flynn Effect, may help explain why the average IQ score across the general population has risen by around 3 points per decade. The trend is further complicated by the fact that later-born groups have tended to experience a sharper decline in cognition, compared to older-born cohorts, whose cognitive issues have tended to come on more gradually.

Although some genetic and biological factors may make cognitive decline an inevitability for certain people, scientists have long sought to better isolate and change "modifiable factors'' — aspects of the environment that could be shifted to better protect the population from age-related cognitive decline. Multiple variables likely act simultaneously to determine one's likelihood of developing age-related cognitive problems: Weight gain or loss, difficult life events, underlying psychiatric conditions and eating habits could all play a role.

The researchers said their findings should not be interpreted to mean that improvements to the education system are unnecessary. Instead, they think policymakers should explore how additional environmental changes could more directly protect against cognitive decline.

"Our findings suggest that models that include early education for this specific purpose may need to be modified, Lars Nyberg, a professor of neuroscience at Umeå University and another co-lead author of the study, told The Academic Times. "Instead, other factors [could] be highlighted, like physical activity."

The study, "Educational attainment does not influence brain aging" published April 26 in Proceedings of the National Academy of Sciences, was authored by Lars Nyberg, Umeå University and University of Oslo; Fredrik Magnussen and Øystein Sørensen, University of Oslo; Anders Lundquist and Sara Pudas, Umeå University; William Baaré, Copenhagen University Hospital; David Bartrés-Faz, Carme Junqué and Lídia Vaqué-Alcázar, University of Barcelona; Lars Bertram, University of Oslo and University of Lübeck; C. J. Boraxbekk, Umeå University and Copenhagen University Hospital; Andreas M. Brandmaier and Ulman Lindenberger, Max Planck Institute for Human Development and Max Planck University College London Centre for Computational Psychiatry and Ageing Research; Christian A. Drevon, Vitas Analytical Services and University of Oslo; Klaus Ebmeier, University of Oxford; Richard N. Henson and Ethan Knights, University of Cambridge; Paolo Ghisletta, University of Geneva; Rogier Kievit, University of Cambridge and Radboud University Medical Center; Maike Kleemeyer, Max Planck Institute for Human Development; Simone Kühn, Max Planck Institute for Human Development and University Clinic Hamburg-Eppendorf; Brenda W. J. H. Penninx, Vrije Universiteit Amsterdam; and Kristine B. Walhovd and Anders M. Fjell, University of Oslo and Oslo University Hospital.