The team found that individuals with variants near a gene called Apolipoprotein E had poorer scores on memory tests.
The study, led by Prof. Ian Deary of the University of Edinburgh in the UK, is published in the journal Biological Psychiatry.
Prof. Deary and his colleagues - who come from the UK, US, France, Germany, Switzerland, Austria, Finland, Holland, Croatia, Australia and Taiwan - say this is the first study to find a link between common genetic variants and the ability to recall lists of words and stories.
"These international collaborations help us to find the small individual genetic variants that contribute to memory and other important skills," says Prof. Deary.
They hope their findings could help predict which people will experience difficulties with their memory as they age.
To conduct their study, the researchers used data from five studies based at the University of Edinburgh: the Lothian Birth Cohort 1921 and 1936, the Orkney Complex Disease Study (ORCADES) and the Croatia-Korčula and Croatia-Split cohorts.
All together, these make up the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Consortium, which analyzed data from 30,000 individuals over the age of 45.
To conduct their study, the researchers had the participants - who were all free of dementia - undergo memory tests that involved recalling words and stories after an assigned time period.
Individuals with genetic variants had signs of early Alzheimer's in brain tissue
After the memory tests were complete, the researchers analyzed the results along with personal genome data to determine any genetic variants or changes that were linked with lower memory scores.
Results showed that individuals with lower overall scores had variants near a gene called Apolipoprotein E and other gene involved with immune responses.
The researchers note that previous research has indicated that some forms of Apolipoprotein E are linked with increased risk of dementia, including Alzheimer's.
In this latest study, participants with a lower score in remembering short stories had variants near Apolipoprotein E, and those with a lower score in remembering word lists had a mutation near the gene involved in immune responses.
Additionally, the researchers checked 725 postmortem brain tissue samples and determined that individuals with the genetic variants related to poorer test scores were more likely to have signs of early Alzheimer's disease.
Commenting on their findings, lead author Dr. Stéphanie Debette, from Boston University School of Medicine, says:
"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. The differential associations according to memory test characteristics and age should be accounted for in future studies."
The researchers add that their findings could help them better understand the link between immune system problems and memory loss that comes with age.
Medical News Today recently reported on a study that identified a specific brain network that is more vulnerable to conditions such as Alzheimer's and schizophrenia.