The Secret to Preserving Brain Health as You Age
As people grow older, it’s common to experience cognitive decline, particularly in areas like episodic memory. However, a unique group of older adults, known as “superagers,” defy this trend by maintaining remarkably strong memory abilities comparable to those 30 years younger. What is the secret to their cognitive resilience? Recent research has found that superagers exhibit a remarkable resistance to typical age-related changes in the brain’s white matter structure.
In a comprehensive study published in the Journal of Neuroscience, researchers from the Vallecas Project in Madrid, Spain, examined the white matter health and microstructure of 64 superagers and 55 typical older adults over a 5-year period. While the two groups showed no notable differences in global measures of white matter, such as total volume or lesion severity, the superagers displayed superior white matter integrity at a regional level.
Superagers Exhibit Stronger White Matter Microstructure
The key finding of this study was that superagers exhibited higher fractional anisotropy (FA) and lower mean diffusivity (MD) in specific white matter tracts, particularly in the frontal regions of the brain. These diffusivity measures provide insights into the microstructural properties of white matter, with higher FA indicating stronger directionality of water diffusion and lower MD reflecting tighter tissue constraints.
“The study has found a better preservation of white matter microstructure over time in superagers when compared to an elderly control group with normal memory for their age,” explained Marta Garo, PhD, the study’s first author and a neurobiologist at the Laboratory for Clinical Neuroscience at the Universidad Politécnica de Madrid.
This preservation of white matter microstructure in superagers was most pronounced in anterior brain regions and tracts with protracted maturation, such as the anterior thalamic radiation and association fibers. These are the very areas that tend to be most vulnerable to age-related changes, according to the “last-in-first-out” hypothesis.
“This can be interpreted as superagers can avoid the normal aging changes that occur in white matter microstructure, for that reason we say in the title that superagers resist typical age-related white matter structural changes,” Garo added.
Longitudinal Insights: Superagers Slow the Decline
The researchers also examined the longitudinal trajectories of white matter changes over the 5-year study period. While both superagers and typical older adults experienced some degree of white matter decline, the rate of change was significantly slower in the superager group.
Specifically, the team found that the decrease in FA over time was slower in superagers compared to typical older adults across all the white matter tracts assessed. Similarly, the increase in MD over time was slower in superagers, except for a few tracts like the corticospinal tract, uncinate fasciculus, and forceps minor.
These findings suggest that superagers are able to resist the typical age-related deterioration of white matter microstructure, particularly in the vulnerable anterior brain regions and protracted maturation tracts.
Implications for Understanding Brain Resilience
The superior white matter microstructure observed in superagers provides important insights into the mechanisms underlying their remarkable cognitive abilities. As Garo explained, “The paradigm of superagers shows how an old person can naturally age with excellent memory. This is key when trying to fight against the pathological deterioration of memory because the study of the superager brain will help us understand which brain structures are important to have a good memory as we age.”
By identifying the brain regions and white matter tracts that are better preserved in superagers, researchers may be able to pinpoint specific targets for interventions aimed at enhancing brain resilience and delaying cognitive decline.
“The identification of these structures could potentially help to inform brain stimulation treatments,” Garo noted.
Lifestyle Factors and Brain Health
In a previous study on the same cohort of superagers, the researchers found that this exceptional group exhibited several lifestyle and health factors that differentiated them from typical older adults, including:
- Better mobility and mental health
- Lower incidence of glucose disorders and hypertension
- Greater engagement in hobbies, such as music
While the researchers caution that these factors cannot be directly linked to the superaging phenotype, Garo emphasized that “having good mental and physical health, as well as having hobbies, could contribute to healthy aging.”
Neuroscientist Ben Rein, PhD, who was not involved in this research, agrees that lifestyle factors play a crucial role in preserving brain health as we age.
“Sleep and physical exercise are proven pillars of brain health, but social interaction doesn’t get enough attention,” Rein said. “As we age, we spend more time alone, and isolation is bad for the brain. Spending time with others is a great way to exercise and protect your brain.”
Rein also highlighted the importance of mental stimulation, noting that “engaging in cognitive activities and challenges — i.e., reading, puzzles, hobbies — exercises pathways in your brain that may otherwise be vulnerable to atrophy.”
Unlocking the Secrets of Successful Aging
The findings from this study on superagers provide valuable insights into the mechanisms underlying cognitive resilience and successful aging. By understanding how superagers are able to resist typical age-related changes in white matter structure, researchers may uncover new strategies for preserving brain health and delaying the onset of cognitive decline.
As Rein succinctly put it, “The brain is like a muscle: The more you use it, the stronger it will be, and the more resistant it will be to atrophy.”
By incorporating healthy lifestyle habits, engaging in mentally stimulating activities, and potentially leveraging targeted brain-based interventions, individuals may be able to emulate the remarkable cognitive abilities of superagers and age more gracefully.
