Having a Family History of Alzheimer’s Disease Can Alter Cognition

A team of researchers developed an internet-based paired associates learning (PAL) task that revealed adults with a family history (FH) of Alzheimer’s disease perform poorly on learning assessments compared to people without a family history of Alzheimer’s. This learning impairment appears to be compounded in those with diabetes or a genetic flaw in the apolipoprotein E (APOE) gene. The findings was published in eLIFE.

“Identifying factors that reduce or eliminate the effect of a family history of Alzheimer’s disease is particularly crucial since there is currently no cure or effective disease-slowing treatments,” says lead author Joshua Talboom, PhD, a Postdoctoral Fellow at the Translational Genomics Research Institute in Arizona, US in a press release.

In this study, researchers tested 59,571 individuals (62% female, 92% white) between the ages of 18-85 to who participated in PAL assessment, called MindCrowd. After consenting to the study and answering demographic questions regarding age, sex, education, primary language, and country of residence, the participants were prompted to complete 12 word-pairs, one word-pair at a time. Subsequently, in the recall phase, participants were shown the first word of each pair and instructed to type in the missing word. The recall phase was repeated over two additional task intervals. Before commencing their tasks, each participant received one practice trial consisting of three word-pairs not contained in the 12 used during the test. Word-pairs were presented in random orders during each learning and recall phase. The same word pairs and orders of presentation were used for all participants.

Diabetes, and Gene Alterations Play a Factor

According to the results of the study, FH was associated with lower PAL performance in both males and females under the age of 65. Key factors of this effect of FH on PAL performance included age, sex, education, and diabetes. Moreover, a variation in APOE gene was also associated with lower PAL scores in FH positive individuals. “The APOE genotype is an important genetic factor that influences memory, and we found that those with the variation performed worse on the memory test than those without the variation,” Dr. Talboom continued.

“Collectively, this study supports recommendations underscoring the importance of living a healthy lifestyle, properly treating disease states such as diabetes, and building cognitive reserve through education to attenuate age- and AD-risk-related cognitive declines,” Dr. Talboom added, and further said that “our findings specifically highlight the positive effects of such interventions on FH-associated risk, opening the door to the development of more targeted risk reduction approaches to combat AD. In addition, this work underscores the utility of web-based cohort recruitment and study; thus, facilitating large sample sizes in a cost- and time-effective fashion.”

Source: eLIFE, EurekAlert