Scientists have discovered a new trait unique to a special group of octogenarians whom they’ve dubbed super-agers — older adults who retain a much sharper memory than their peers.
STAT chatted with study author Emily Rogalski of Northwestern University about the work, published in the Journal of the American Medical Association.
Who counts as a super-ager?
When you think about normal aging, memory performance starts to decline in our late 20s and 30s. But when you look at individual data points, there’s a lot of variability in decline in our later years. There are people who seem to avoid this decline in memory performance. For our purposes, they have to be over age 80, and they have to have memory performance better than individuals in their 50s and 60s. It took us a couple years just to develop a cohort to start to study. We screened well over 1,000 people who thought they had outstanding memory. And of those people, under 5 percent qualified for the research.
What did you discover about how their brains age?
We already knew their brains are bigger than their peers. But we wanted to know if it was because they were born with bigger brains, or if it was more because they’re on a truly different aging trajectory and aren’t losing brain mass at the same rate as an average ager. We used MRI to measure the thickness of their cortex [the outer layer of the cerebrum] and compared those to average agers. Compared over an 18-month period, the average agers are atrophying at more than twice the rate than that of the super-agers. They seem to be resistant in some way to the atrophy process that’s common in average aging. The next natural question is how you get on the slow-atrophy train. And that’s certainly an important next step.
How can you parse out those potential contributing factors?
We want to study the composition of the cortex and which neurons are most vulnerable in aging. And we want to know which things are protective — what kinds of activities are they participating in that may help them resist this change? We can attack this from a biological perspective, but also a psychosocial and lifestyle perspective.