Published in Biological Psychiatry, the findings are a significant step towards better understanding how memory loss is inherited.
The Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium, which involved Monash University researchers, analysed data from nearly 30,000 individuals.
Researchers had the participants – who did not have dementia – complete memory tests. Their entire genome was then genotyped, and using sophisticated statistical analysis was examined for segments that were associated with low memory scores.
The researchers found genetic variants near the Apolipoprotein E gene – known to harbour an increased risk of dementia (especially Alzheimers disease) – were associated with poorer memory performance, mostly in the oldest participants and for short story recall.
Funded by the National Health and Medical Research Council (NHMRC), Associate Professor Velandai Srikanth, School of Clinical Sciences at Monash Health, and his team of Australian collaborators contributed to the analysis and report using data collected from the Tasmanian Study of Cognition and Gait (TASCOG).
“It is exciting to contribute to such a large international collaboration, which offers great opportunities towards understanding mechanisms involved in brain ageing and dementia,” said Associate Professor Srikanth.
“Ultimately the knowledge derived from these studies will assist in efforts to preserve brain health in ageing individuals and offset the risk of dementia.”
Lead author, Adjunct Associate Professor of Neurology at Boston University School of Medicine, Stéphanie Debette, said: “Interestingly genetic variants associated with memory performance also predicted altered levels of expression of certain genes in the hippocampus, a key region of the brain for the consolidation of information.”
“These were mainly genes involved in the metabolism of ubiquitin that plays a pivotal role in protein degradation.”
The study has generated important hypotheses on the biological underpinnings of memory decline in old age, however the researchers caution that more work is needed to confirm the findings.