Staying Sharp as We Age
The limited role of genetics versus lifestyle choices.
Posted Sep 29, 2020
Many of us would like to maximize our chances of aging well and staying sharp. But how much control do we have over the process of brain aging? What can we do to protect ourselves from the risk of dementia? Is there anything we can do to maintain our cognitive abilities as we get older?
Recently published studies from the University of Texas system have helped us understand how changes in both the grey and the white matter of the human brain may contribute to cognitive losses as we age. This new information suggests links between specific genes and the rapid loss of grey matter, which is a hallmark of dementia (Hofer et al., 2020). Discouraging, right? Not entirely.
The majority of instances of cognitive decline are not in the category of dementia. Most of us can influence our brain health as we age. It helps to refresh ourselves on the difference between "cognitive decline" versus dementia. There are differences in severity and in progression.
Dementia is "a progressive loss of cognitive function, marked by memory problems, trouble communicating, impaired judgment, and confused thinking. It is caused by damage to brain cells and usually worsens over time. Dementia most often occurs during old age but is a more severe form of decline than normal aging."
Mild Cognitive Impairment (MCI) is "a decline in cognitive function that may include compromised memory, language, or critical thinking. It is considered more serious than expected age-related decline but less serious and concerning than dementia."
Roughly 10% of adults over age 65 develop MCI. Another 30 to 40% have a mild cognitive loss in memory, which is referred to here as “expected age-related decline.”
Of course, we cannot control whether our parents have passed down to us the genes that increase risk for dementia. One can hope that more effective dementia treatment will become available in the future, but we cannot change our individual genotype.
However, the new research from the University of Texas does not provide any evidence that these genes are the primary cause of Mild Cognitive Impairment (MCI), or of the still more prevalent “expected age-related decline.” Although both age and genetics are believed to be risk factors for MCI, the remaining risk factors for MCI are subject to our personal choices. As summarized by Dr. Nicole Anderson, these factors include “Lack of intellectual engagement, metabolic health, and depression.” We can keep our minds challenged, as well as manage our diet, exercise and sleep routines.
The good news is that “aging alone is generally not a cause of cognitive decline.” People who believe in the possibility of maintaining their memory may be more likely to keep their minds active and to keep their bodies in good health. What we believe influences what we do for ourselves and our well-being.
Hofer et al. Genetic correlations and genome-wide associations of cortical structure in general population samples of 22,824 adults. Nature Communications. (First published 9/22/2020).