A new study brings scientists closer to understanding what makes some people "superagers," which classifies someone as being in their 80s with the memory function of someone decades younger.
In the study, participants who fit this category had more gray matter in parts of the brain involved in memory and movement and performed better in mobility, agility, and balance tests compared to typical adults of the same age, despite having the same level of physical activity.
The study that appeared in the peer-reviewed journal Lancet used data from The Vallecas Project in Madrid, research that includes 1,213 participants aged 69 to 86 years with no neurological or severe psychiatric disorders.
Using a test that assesses memory function, the researchers identified 64 superagers and 55 typical older adults who performed well on cognitive tasks but did not display superager memory ability. All the participants were 79.5 years or older.
As in previous studies, MRI scans showed superagers to have more gray matter — tissue vital for normal brain function — in key brain areas involved in memory and movement. Over five years, the level of gray matter in these areas degenerated more slowly in these folks compared to typical older adults.
In clinical tests, they scored lower on anxiety and depression than typical older adults. Moreover, blood sample analysis indicated that they have lower levels of neurodegeneration biomarkers than typical older adults.
They also performed better in tests examining mobility and fine motor function, indicating they have better agility and balance than do typical older adults, although both groups self-reported similar exercise levels.
"Though superagers report similar activity levels to typical older people, it's possible they do more physically demanding activities like gardening or stair climbing. From lower blood pressure and obesity levels to increased blood flow to the brain, there are many direct and indirect benefits of being physically active that may contribute to improved cognitive abilities in old age," Senior author Bryan Strange of the Universidad Politécnica de Madrid.
The study observed self-reported differences. For example, superagers in midlife were more active, were more satisfied with their sleep duration, and were more likely to have a musical background — either taught or amateur — than did typical older adults.
However, the study does not establish a causal relation between these factors and superaging. Additionally, the machine learning model was only able to distinguish superagers from typical older adults around 66% of the time, indicating that additional factors — possibly genetic — are linked with superaging.
Earlier research has shown that in superagers, the cortex, the brain's outermost layer responsible for thinking and memory, remains much thicker than in healthy 50 to 60-year-olds. Their brains also have significantly fewer tangles, which indicate Alzheimer's disease, and a larger supply of von Economo neurons linked to communication and higher social intelligence.
Although the new study does not definitively prove what makes some people age well, the findings bring scientists closer to uncovering secrets of healthy aging.
- The Lancet. Brain structure and phenotypic profile of superagers compared with age-matched older adults: a longitudinal analysis from the Vallecas Project.
- EurekaAlert. THE LANCET HEALTHY LONGEVITY: Razor-sharp memory function in older adults linked to faster movement and better mental health, study suggests.
- JNeurosci. Morphometric and Histologic Substrates of Cingulate Integrity in Elders with Exceptional Memory Capacity.
- Northwestern Medicine. SuperAger Brains Yield New Clues To Their Remarkable Memories.