Individuals with the genes APOE and CLU have been shown to have higher risks of developing Alzheimer’s disease and dementia; however, a growing body of research suggests that lifestyle and other factors can impact risk of dementia or rate of cognitive decline. A recent study looked at which factors provided “memory resilience”—sustaining high memory function despite genetic risk factors—for those at higher genetic risk for Alzheimer’s and memory decline.
The study looked at the memory resilience of 642 adults with either the APOE or CLU genes between ages 53 and 95 over the course of nine years. Researchers examined 22 non-genetic risk factors to see how predictive they were for memory resilience. These were grouped into five main categories: demographic, functional (BMI, grip strength etc.), health (depression, diabetes etc.), mobility, and lifestyle. In addition, they looked at men and women separately. Memory resilience was measured by scores of three-word recall tests.
For individuals with APOE genes, the analysis of female participants showed age as the major predictor of memory resilience, in line previous research showing risk of Alzheimer’s increasing with age. Other predictors (in decreasing order of influence) were everyday novel cognitive activity (e.g., learning a language), education, working time, volunteering, pulse pressure, and social visits. For men with APOE, the impact of age was very close to that seen for women, but otherwise there were many fewer predictors than for women. For men, other main predictors (in decreasing order of influence) were education, everyday novel cognitive activity, grip strength, and depressive symptoms.
For those with the CLU gene, again women had more factors that predicted resilience, but for this gene education was the strongest predictor, followed by subjective health, pulse pressure, turning time, grip strength, social visits, everyday cognitive activity, walking time, and then age. Education was also the strongest for men, followed by grip strength, age, depressive symptoms volunteering, social visits, and pet ownership.
Overall, this study shows that a number of non-genetic factors can play a role in providing memory resilience even for those with genetic predispositions to Alzheimer’s, a number of which are modifiable by lifestyle change. The data also shows that sex and gene type are important in relation to which factors provide the most impact.