Why our aging brains require custom care

Researchers propose a new model for studying age-related cognitive decline—one that’s tailored to the individual, a study reports.

People are living longer than ever before, but brain health isn’t keeping up. There’s no such thing as a one-size-fits-all approach to aging brain health, says Lee Ryan, professor and head of the University of Arizona’s psychology department.

A number of studies have looked at individual risk factors that may contribute to cognitive decline with age, such as chronic stress and cardiovascular disease. However, those factors may affect different people in different ways depending on other variables, such as genetics and lifestyle, Ryan says.

Ways of aging

In a paper in the journal Frontiers in Aging Neuroscience, Ryan and colleagues advocate for a more personalized approach, borrowing principles of precision medicine in an effort to better understand, prevent, and treat age-related cognitive decline.

“Aging is incredibly complex, and most of the research out there was focusing on one aspect of aging at a time,” Ryan says. “What we’re trying to do is take the basic concepts of precision medicine and apply them to understanding aging and the aging brain.

“There’s not just one way of aging.”

“Everybody is different and there are different trajectories. Everyone has different risk factors and different environmental contexts, and layered on top of that are individual differences in genetics. You have to really pull all of those things together to predict who is going to age which way. There’s not just one way of aging.”

Although most older adults—around 85 percent—will not experience Alzheimer’s disease in their lifetimes, some level of cognitive decline is considered a normal part of aging. The majority of people in their 60s or older experience some cognitive impairment, Ryan says.

This not only threatens older adults’ quality of life, it also has socioeconomic consequences, amounting to hundreds of billions of dollars in health care and caregiving costs, as well as lost productivity in the workplace, Ryan and her coauthors write.

3 areas of research

The researchers have a lofty goal: to make it possible to maintain brain health throughout the entire adult lifespan, which today in the US is a little over 78 years old on average.

In their paper, Ryan and coauthors present a precision aging model meant to be a starting point to guide future research. It focuses primarily on three areas: broad risk categories; brain drivers; and genetic variants.

Cardiovascular health, consistently linked to brain health, is an example of a risk category for age-related cognitive decline, researchers say. The broader risk category includes within it several individual risk factors, such as obesity, diabetes, and hypertension.

“Kids that are born in this decade probably have a 50% chance of living to 100.”

The model then considers brain drivers, or the biological mechanisms through which individual risk factors in a category actually affect the brain. This is an area where existing research is particularly limited, Ryan says.

Finally, the model looks at genetic variants, which can either increase or decrease a person’s risk for age-related cognitive decline. Despite people’s best efforts to live a healthy lifestyle, genes do factor into the equation and can’t be ignored, Ryan says. For example, there are genes that protect against or make it more likely that a person will get diabetes, sometimes regardless of their dietary choices.

While the precision aging model is a work in progress, the researchers believe that considering the combination of risk categories, brain drivers, and genetic variants is key to better understanding age-related cognitive decline and how to best intervene in different patients.

Ryan says she imagines a future in which you can go to your doctor’s office and have all of your health and lifestyle information put into an app that would then help health-care professionals guide you on an individualized path for maintaining brain health across your lifespan.

We may not be there yet, but it’s important for research on age-related cognitive decline to continue, as advances in health and technology have the potential to extend the lifespan even further, she says.

“Kids that are born in this decade probably have a 50 percent chance of living to 100,” Ryan says. “Our hope is that the research community collectively stops thinking about aging as a single process and recognizes that it is complex and not one-size-fits-all. To really move the research forward you need to take an individualized approach.”

Additional researchers are from the University of Arizona, Georgia Institute of Technology, Johns Hopkins University, the Leonard M. Miller School of Medicine, and the Translational Genomics Institute.

Source: University of Arizona