A Swiss long-term study found that certain degenerative processes are reduced in the brains of academics, with their brains better able to compensate for age-related cognitive and neural limitations.
The findings add to initial findings of other research groups, who have found that education has a positive effect on brain ageing. Previous studies also suggest that mental processing speed depends on the integrity of neural networks in the brain.
The study by was by University Research Priority Programme Dynamics of Healthy Aging, led by Lutz Jäncke, professor of neuropsychology at the University of Zurich, study, and was published in NeuroImage: Clinical.
The researchers followed more than 200 senior citizens for more than seven years. The study participants are not affected by dementia, have average to above-average intelligence and lead highly active social lives.
They were examined neuroanatomically as well as neuropsychologically using magnetic resonance imaging at regular intervals. Based on statistical analyses, the researchers were able to show that academic education may have a positive effect on age-related brain degeneration.
White spots and black holes
In her PhD thesis, first author Isabel Hotz used novel automatic methods, among others, to study so-called lacunes and white matter hyperintensities. These degenerative processes showed up as “black holes” and “white spots” on the digital images. The reasons for this are not yet known and may have to do with small, unnoticed cerebral infarcts, reduced blood flow or loss of nerve pathways or neurons. This can limit a person’s cognitive performance, particularly when degeneration affects key regions of the brain.
The findings revealed that over the course of seven years, senior citizens with an academic background showed a significantly lower increase in these typical signs of brain degeneration. “In addition, academics also processed information faster and more accurately, for example, when matching letters, numbers of patterns. The decline in their mental processing performance was lower overall,” summarises Hotz.
Tapping into reserves
Even though no causal link between education and reduced natural brain degeneration has so far been found, the following at least seems likely: “We suspect that a high level of education leads to an increase in neural and cognitive networks over the course of people’s lives, and that they build up reserves, so to speak. In old age, their brains are then better able to compensate any impairments that occur,” says Jäncke.
It is also possible that brains that are active well into old age are less susceptible to degeneration processes, adds the neuropsychologist, though this would have to be verified in the further course of the ongoing long-term study.
Associations of subclinical cerebral small vessel disease and processing speed in non-demented subjects: A 7-year study.
Isabel Hotz, Pascal Frédéric Deschwanden, Susan Mérillat, Franziskus Liem, Spyridon Kollias, Lutz Jäncke
Published in NeuroImage: Clinical, Volume 32, 2021
Markers of cerebral small vessel disease (CSVD) have previously been associated with age-related cognitive decline. Using longitudinal data of cognitively healthy, older adults (N = 216, mean age at baseline = 70.9 years), we investigated baseline status and change in white matter hyperintensities (WMH) (total, periventricular, deep), normal appearing white matter (NAWM), brain parenchyma volume (BPV) and processing speed over seven years as well as the impact of different covariates by applying latent growth curve (LGC) models. Generally, we revealed a complex pattern of associations between the different CSVD markers. More specifically, we observed that changes of deep WMH (dWMH), as compared to periventricular WMH (pWMH), were more strongly related to the changes of other CSVD markers and also to baseline processing speed performance. Further, the number of lacunes rather than their volume reflected the severity of CSVD. With respect to the studied covariates, we revealed that higher education had a protective effect on subsequent total WMH, pWMH, lacunar number, NAWM volume, and processing speed performance. The indication of antihypertensive drugs was associated with lower lacunar number and volume at baseline and the indication of antihypercholesterolemic drugs came along with higher processing speed performance at baseline. In summary, our results confirm previous findings, and extend them by providing information on true within-person changes, relationships between the different CSVD markers and brain-behaviour associations. The moderate to strong associations between changes of the different CSVD markers indicate a common pathological relationship and, thus, support multidimensional treatment strategies.
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