Literature Review

Which factors distinguish superagers from the rest of us?


 

FROM THE LANCET HEALTHY LONGEVITY

Even at an advanced age, superagers have the memory of someone 20 or 30 years their junior. But why is that? A new study shows that, in superagers, age-related atrophy of the gray matter, especially in the areas responsible for memory, develops much more slowly than in normal older adults. However, the study also emphasizes the importance of physical and mental fitness for a healthy aging process.

“One of the most important unanswered questions with regard to superagers is: ‘Are they resistant to age-related memory loss, or do they have coping mechanisms that allow them to better offset this memory loss?’ ” wrote Marta Garo-Pascual, a PhD candidate at the Autonomous University of Madrid, Spain, and colleagues in the Lancet Healthy Longevity. “Our results indicate that superagers are resistant to these processes.”

Six years’ monitoring

From a cohort of older adults who had participated in a study aiming to identify early indicators of Alzheimer’s disease, the research group chose 64 superagers and 55 normal senior citizens. The latter served as the control group. While the superagers performed just as well in a memory test as people 30 years their junior, the control group’s performance was in line with their age and level of education.

All study participants were over age 79 years. Both the group of superagers and the control group included more females than males. On average, they were monitored for 6 years. During this period, a checkup was scheduled annually with an MRI examination, clinical tests, blood tests, and documentation of lifestyle factors.

For Alessandro Cellerino, PhD, of the Leibniz Institute on Aging–Fritz Lipmann Institute in Jena, Germany, this is the most crucial aspect of the study. “Even before this study, we knew that superagers demonstrated less atrophy in certain areas of the brain, but this was always only ever based on a single measurement.”

Memory centers protected

The MRI examinations confirmed that in superagers, gray matter atrophy in the regions responsible for memory (such as the medial temporal lobe and cholinergic forebrain), as well in regions important for movement (such as the motor thalamus), was less pronounced. In addition, the volume of gray matter in these regions, especially in the medial temporal lobe, decreased much more slowly in the superagers than in the control subjects over the study period.

Ms. Garo-Pascual and associates used a machine-learning algorithm to differentiate between superagers and normal older adults. From the 89 demographic, lifestyle, and clinical factors entered into the algorithm, two were the most important for the classification: the ability to move and mental health.

Mobility and mental health

Clinical tests such as the Timed Up-and-Go Test and the Finger Tapping Test revealed that superagers can be distinguished from the normally aging control subjects with regard to their mobility and fine motor skills. Their physical condition was better, although they, by their own admission, did not move any more than the control subjects in day-to-day life. According to Dr. Cellerino, this finding confirms that physical activity is paramount for cognitive function. “These people were over 80 years old – the fact that there was not much difference between their levels of activity is not surprising. Much more relevant is the question of how you get there – i.e., how active you are at the ages of 40, 50 or even 60 years old.”

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