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Whenever we hear the term “senior moment” from an elderly person struggling to find the right word in a conversation, we often assume that memory naturally worsens with aging. Episodic memory is one of the cognitive abilities most vulnerable to aging.

“Episodic memory is one of the cognitive abilities most vulnerable to aging”.

People experiencing such senior moments on a regular basis worry about these symptoms in particular if they have read about the projected increase in the incidence of Alzheimer’s disease (AD). Today, nearly 7 million Americans are living with a diagnosis of AD and by 2050, this number is projected to rise to nearly 13 million with staggering personal and public health implications.

“…there is new evidence that some individuals may even be able to maintain full cognitive function and memory as they experienced when much younger.”

However, while a certain decline in our cognitive functions with age may be the norm for the great majority of people, only a small percentage of the elderly develops progressive cognitive decline. And there is new evidence that some individuals may even be able to maintain full cognitive function and memory as they experienced when much younger.

For a little over a decade, scientists have been studying this subset of people they call “super-agers.” These individuals are age 80 and up, but they have the memory ability of a person 20 to 30 years younger.

As quoted in a recent article in the New York Times by Dana Smith, Emily Rogalski, a professor of neurology at the University of Chicago, who published one of the first studies on super-agers in 2012 stated: “if we’re constantly talking about what’s going wrong in aging, it’s not capturing the full spectrum of what’s happening in the older adult population”

“…aimed to study elderly individuals with the memory ability of people 30 years younger to provide evidence that age-related cognitive decline is not inevitable.”

A recent report by Marta Garo-Pascual and Bryan A. Strange recently published in the Journal of Neuroscience aimed to study elderly individuals with the memory ability of people 30 years younger to provide evidence that age-related cognitive decline is not inevitable. In a sample of 64 super-agers with a mean age of 82 years (59% women) and 55 typical older adults of similar age and sex distribution from the Vallecas Project, they studied different aspects of the white matter of the brain with a technique called diffusion imaging over 5 years with yearly follow-ups. (The Vallecas Project is a longitudinal cohort recruited between Oct 10, 2011, and Jan 14, 2014, aged 79.5 years or older, on the basis of their delayed verbal episodic memory score). The study revealed better white matter microstructure in super-agers than in typical older adults. The better preservation of white matter microstructure in super-agers relative to typical older adults supports resistance to age-related brain structural changes as a mechanism underpinning the remarkable memory capacity of these individuals.

In an earlier publication, Bryan A. Strange and co-investigators reported research results from the same Vallecas cohort. The participants completed multiple tests assessing their memory, motor and verbal skills; underwent brain scans and blood draws; and answered questions about their lifestyle and behaviors.

“…super-agers had more volume in areas of the brain important for memory, most notably the hippocampus and entorhinal cortex.”

The scientists found that the super-agers had more volume in areas of the brain important for memory, most notably the hippocampus and entorhinal cortex. Previous studies have shown that several interventions, like regular physical exercise and flavonol supplementation can slow the age related decline in cognitive function and affect these particular brain regions. They also had better preserved connectivity between regions in the front of the brain that are involved in cognition. Both the super-agers and the control group showed minimal signs of AD in their brains. However, super-agers exhibited slower overall grey matter atrophy, particularly in memory-related regions.

“…faster movement speed (despite no group differences in exercise frequency) and better mental health were the most differentiating factors for super-agers.”

A machine learning classification including 89 demographic, lifestyle, and clinical predictors showed surprisingly that faster movement speed (despite no group differences in exercise frequency) and better mental health were the most differentiating factors for super-agers. In addition, they reported lower anxiety and depression levels, better sleep quality and fewer instances of hypertension and type II diabetes, all known risk factors for cognitive decline. The amount of education did not differ between the groups, and there no group differences in APOE ε4 frequency, the major genetic risk factor for non-familial AD, nor in blood biomarkers of dementia.

“Understanding these factors [underlying the resistance to age-related aging of the brain] could lead to the urgently needed progress in the development of effective AD treatments and prevention.”

The authors acknowledged that despite introducing 89 variables into their statistical model, the classification accuracy of less than 70% indicates that other variables, possibly including genetic factors, are associated with the super-aging phenotype. In addition, they emphasized that their results were observational and do not allow to make any inferences about which factors are causally related to the super-aging phenotype. They concluded that “the brain structural signature and clinical and lifestyle factors associated with the super-aging phenotype probably reflect a resistance to age-related memory decline. Understanding these factors could lead to the urgently needed progress in the development of effective AD treatments and prevention.