Aging often leads to cognitive decline, particularly in memory function, and is associated with neurodegenerative diseases like Alzheimer’s. However, a unique group of older adults known as “superagers” defy this trend by maintaining memory comparable to much younger individuals. Researchers analyzing the white matter of superagers over a 5-year period found that, despite similar overall white matter health with typical older adults, superagers exhibited superior microstructure in specific frontal region fibers, suggesting resistance to age-related cognitive decline. In a new study, researchers examined the structural integrity of white matter in superagers using diffusion imaging to explain how these individuals are able to preserve their cognitive abilities.
As people age, the brain undergoes structural and functional changes that can lead to declines in cognitive abilities, particularly affecting episodic memory. These declines are often linked to neurodegenerative conditions like Alzheimer’s disease. Superagers, however, are able to resist typical age-related changes in gray matter. In the recent study, researchers analyzed the white matter of superagers over a 5-year span, contrasting them with typical older adults. Although there were no notable differences in the overall health of their white matter, superagers displayed superior microstructure in certain white matter fibers, especially in the frontal region. This finding indicates their ability to resist cognitive decline typically associated with aging.
The study involved 64 superagers and 55 typical older adults selected from the Vallecas Project cohort in Madrid, Spain. MRI data was collected to evaluate brain white matter health and microstructure, focusing on white matter volume, lesion volume, and white matter hyperintensities using the Fazekas scale, which are associated with cognitive decline. Diffusion-weighted images were processed and analyzed, revealing that superagers initially performed better on cognitive tests, but both groups showed similar rates of cognitive decline over time, except for a slower decline in animal fluency among superagers. While there were no significant differences in total white matter volume, white matter lesions, or severity of lesions between the groups, detailed analysis showed superagers had higher fractional anisotropy and lower mean diffusivity in certain brain regions, particularly in the frontal areas, indicating their resistance to cognitive decline.
Marta Garo, a neurobiologist involved in the study, explained that superagers show better preservation of white matter microstructure over time compared to typical elderly individuals with normal memory for their age. By studying superagers’ brains, researchers hope to understand which brain structures are important for maintaining a good memory as people age, which could inform potential brain stimulation treatments to fight against cognitive decline. Other experts in the field commented on the significance of the study, highlighting the importance of understanding mechanisms that protect against age-related memory loss and the role of factors like vascular health in cognitive aging.
Superagers have been found to have better mobility, mental health, and overall physical health compared to typical elderly individuals. While controlling factors like good mental and physical health, as well as engaging in hobbies, may contribute to healthy aging, causality cannot be inferred from the study. Recommendations for healthy aging include maintaining good sleep hygiene, regular physical exercise, social interaction, and mental exercise. Social interaction, in particular, is emphasized as vital for brain health, as isolation can be detrimental to cognitive function. Engaging in cognitive challenges and activities can help exercise pathways in the brain, preserving their structure and preventing atrophy. Using the brain more, especially for high-level cognitive tasks, may be linked to greater white matter integrity, making the brain more resistant to decline.
