Superagers Have a Genetic Advantage Against Dementia, Study Says
“Superagers” are people over 80 who are unusually resistant to dementia, with memory and thinking abilities that look more like those of adults in their 50s and 60s. At a time when Alzheimer’s risk rises sharply, affecting roughly 1 in 9 Americans over 65, these adults stand out as rare examples of exceptional brain health. Now, a new study suggests that certain genetic traits may help explain why superagers are able to stay mentally sharp well into their 80s and beyond.
In the study, published in Alzheimer's & Dementia, researchers analyzed data from more than 18,000 people across eight aging studies to see how a key Alzheimer’s-related gene differs in superagers compared to people with Alzheimer’s disease.
The gene, APOE, has several forms. One variant, APOE-ε4, is known to increase the risk of developing Alzheimer’s disease, while another, APOE-ε2, is thought to be protective.
Researchers found superagers were 68 percent less likely to harbor APOE-ε4. Most notably, super agers were 19 percent less likely to harbor APOE-ε4 than were cognitively normal participants in the same age group.
"This was our most striking finding—although all adults who reach the age of 80 without receiving a diagnosis of clinical dementia exhibit exceptional aging, our study suggests that the super-ager phenotype can be used to identify a particularly exceptional group of oldest-old adults with a reduced genetic risk for Alzheimer’s disease," said Leslie Gaynor, PhD, lead study author, and statistical genetic analyst in the Vanderbilt Memory and Alzheimer's Center.
The study also found that superagers were more likely to carry the protective APOE-ε2 variant. They were 28 percent more likely to carry APOE-ε2 than cognitively normal adults over 80, and more than twice as likely as those with Alzheimer’s dementia.
The authors say more research is needed to fully understand what protects the aging brain, but the findings offer strong evidence that genetics plays a big role in preserving memory into later life.