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An international study published in Nature Medicine challenges the widely held belief that higher formal education directly protects against cognitive decline and brain aging. The paper, entitled Reevaluating the role of education in cognitive decline and brain aging, analyzed longitudinal data from more than 170,000 people in 33 Western countries, making it one of the largest studies on cognitive aging conducted to date. The results reinforce the need for policies and programs that promote brain health through factors beyond cognitive activity and that extend throughout the life cycle, not just in childhood and youth. The Institut Guttmann and the University of Barcelona (UB) are the only two Spanish centers that participated in the study, led by the University of Oslo (Norway) within the framework of the European Lifebrain consortium.

According to previous studies, although the total number of people with dementia worldwide is increasing due to population growth and aging, the incidence appears to be declining and older adults today have better cognitive function than 20 years ago. This is attributed to changes in the population's lifestyle, and until now the most widespread hypothesis suggested that formal education could provide protection against neurodegeneration or normal brain aging.

However, the researchers have found that although people with more years of formal education tend to start with a higher cognitive level in adulthood, they do not experience slower cognitive decline with age. “You could say that having a higher level of education puts you at an advantage at the start of the race, but once it starts, it doesn't allow you to go faster or show you any shortcuts: you will face the same obstacles as everyone else and they will affect you in the same way as they affect others,” explains David Bartrés-Faz, Principal Investigator of the Barcelona Brain Health Initiative (BBHI) at the Institut Guttmann and Professor at the Faculty of Medicine and Health Sciences and the Institute of Neurosciences at the University of Barcelona (UBneuro).

Studies published to date presented contradictory results and were often limited to small samples or a single country. The study now published in Nature Medicine has processed more than 420,000 neuropsychological scans and imaging tests from individuals in multiple countries and cohorts—European, American, Asian, and Australian—using different methodologies, making it one of the most robust and generalizable studies on the subject. A total of 170,795 people over the age of 50 participated, belonging to 27 longitudinal cohorts and with follow-up of up to 28 years per participant.

Specifically, the BBHI cohort provided 966 subjects for the study, while the UB provided an additional 161. Participants performed tests of memory, reasoning, processing speed, and language, and 6,472 individuals also underwent brain MRI scans to analyze parameters such as total brain volume and the volume of key regions for memory (hippocampus and prefrontal cortex).

A very similar evolution

According to the results, a higher level of education was associated with better memory, greater intracranial volume, and a slightly larger volume of memory-sensitive brain regions. “A plausible explanation is that it is people's initial neurobiological traits that favor them achieving a higher level of education, and not the other way around,” explains Gabriele Cattaneo, PhD in Biomedicine and researcher at the BBHI. And all groups, regardless of their level of education, showed cognitive decline and brain structure aging that were virtually parallel over time. “This does not detract from the fact that starting with a higher cognitive reserve provides an advantage because if you start higher, you will end up higher. Clearly, education and early schooling improve cognitive function throughout life, but they do not influence the rate of decline or structural aging of the brain. If we take educational level as a reference, all brains change in a very similar way in middle age and old age,” Cattaneo continues.

The study raises important questions for public policy on brain health and healthy aging. “Although promoting education remains essential, the results indicate that it is not enough for healthy aging. In other words, accumulating years of schooling is not enough to protect the brain from aging. A broader, multifactorial approach is required, including lifelong interventions such as physical activity, continuous cognitive stimulation, social relationships, and prevention of vascular risk factors,” highlights Javier Solana, PhD in Biomedical Engineering and Director of Research at the Institut Guttmann.