Is Poor Fitness Associated With Smaller Brain Volume?

Poor fitness in midlife is linked to smaller brain volume two decades later, according to a new study.

“Brain volume is one marker of brain aging,” said lead study author Nicole L. Spartano, PhD, from Boston University School of Medicine. “Our brains shrink as we age, and this atrophy is related to cognitive decline and increased risk for dementia. So it is important to determine the factors—especially modifiable factors, such as fitness—that contribute to brain aging.”
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In the study, Framingham Offspring participants (n=1094, 53.9% female) free from dementia and cardiovascular disease (CVD) underwent an exercise treadmill test at a mean age of 40 +/- 9 years. The researchers administered a second treadmill test and MRI scans of the brain 2 decades later (mean age 58 +/- 8 years).

They found poor cardiovascular fitness and greater diastolic blood pressure (BP) and heart rate response to exercise at baseline were associated with a smaller total cerebral brain volume (TCBV) almost 2 decades later (all p < 0.05) in multivariable adjusted models; the effect of 1 SD lower fitness was equivalent to approximately 1 additional year of brain aging in individuals free of CVD. In participants with prehypertension or hypertension at baseline, exercise systolic BP also was associated with smaller TCBV (p < 0.05).

“The broad message is that health and lifestyle choices that you make throughout your life may have consequences many years later,” Spartano said. “I think many people know that their lifestyle choices have an impact on their weight and risk of diseases like heart disease, but not everyone understands how these lifestyle factors can impact their brain. You never know what might click for different patients in terms of adopting a healthy lifestyle. For some patients, learning that poor fitness in midlife is linked to smaller brain volume might be a powerful message.”

As this current study shows the link between a snapshot of fitness in midlife with a snapshot of brain structure 20 years later, Spartano said she hopes future research will look at changes in lifestyle factors across the lifecourse and how they relate to changes in brain structure/function over time.

-Mike Bederka

Reference:

Spartano NL, Himali JJ, Beiser AS, et al. Midlife exercise blood pressure, heart rate, and fitness relate to brain volume 2 decades later. Neurology. 2016;86:1-7.