Ageing is a key factor of cognitive decline. Lifestyle in general, and, in particular, physical activity is consistently shown to be moderators of the ageing effect on cognition. The explanation of this link on the epigenetic level was not comprehensively examined. One promising explanation in epigenetics is age-associated changes in DNA methylation (DNAm). Research demonstrates that DNAm is connected with cardiovascular health, inflammation, and brain functioning, which are involved in physical activity and cognitive processes. Given that, I examined the potential of DNAm-based measures of ageing to be mediators in the association of physical activity and memory performance. The sample consisted of 181 healthy 64-68 Swedish citizens. Structural equation modelling incorporated two measures of physical activity: total duration per week and subjective intensity, three DNAm-based measures: Horvath age acceleration, PhenoAge acceleration, and DunedinPACE, and scores for working and episodic memory performance. Results revealed that physical activity intensity and not its duration was associated with working and episodic memory. None of the three DNAm-based measures were associated with physical activity intensity. DunedinPACE demonstrated a negative association with working and episodic memory, while Horvath age acceleration and PhenoAge acceleration did not. The positive association of physical activity intensity with cognitive performance for individuals with different DNAm degree and pace of ageing indicates the utility of physical activity for better memory performance for any person. DNAm-based measures showed to be useful biomarkers of individual differences in cognitive ageing. Further research with objective physical activity measures in larger age-heterogeneous samples is needed.
Keywords: working memory, episodic memory, physical activity, DNAm-based measures of ageing, cognitive ageing
Currently, Dmitry is continuing his academic path as a research assistant at Bielefeld University in Germany. He works with twins, genetic and epigenetic data to extend the understanding of the role of genetics and environment in health and behaviour.
Congratulations, Dmitry! We wish you the best of luck with your research assistant position!