The research was performed by Aron K.
Barbey, Associate Professor of the Departments of Psychology and Bioengineering
at the University of Illinois. Along with his colleagues at Illinois,
collaborators also came from Northeastern University in Boston and the
University of Delaware. The researchers studied 51 healthy adults during the
course of the study: 25 men and 26 women age between 18 and 35. Scientists made
a number of elasticity measurements using MRE images of the hippocampus,
drawing links between the participants' performance on a memory test and their
aerobic fitness levels.
According to Guoying Liu, Ph.D. Director of
the NIBIB program on Magnetic Resonance Imaging, "MRE is a technique that
has been used in organs like the liver, where it can assess the tissue
stiffness and offers a reliable, non-invasive method for diagnosing hepatic
fibrosis... This study now demonstrates the tremendous potential for MRE to
provide new quantitative biomarkers for assessing brain health as it relates to
physical fitness. This is particularly significant given the rise in dementia
and Alzheimer's disease occurring in the U.S. and worldwide."
While we often hear about the mental
benefits of exercise, few studies have been able to find direct links between
physical fitness levels and specific brain function. This work was based on
well-established observations of atrophy and reduced hippocampus function in
cognitively declining seniors and developmentally delayed children, with
scientists looking for direct links between physical fitness and brain health.
While scientists have long known about the correlation between fitness and
memory, they have always been puzzled by the similar size of the hippocampus in
both young adults and seniors. As it turns out, much like physical fitness, its
not size that counts but the elasticity or firmness of the hippocampus that is
responsible for how well it functions.
"Most of the work in this area has
relied on changes in the size of the hippocampus as a measure of hippocampal
health and function. However, in young adults, although we see an increase in
memory in more aerobically fit individuals, we did not see differences in
hippocampal size," said Barbey. "Because size is a gross measure of
the structural integrity of the hippocampus, we turned to MRE, which provides a
more thorough and qualitative measure of changes associated with function - in
this case memory." According to Barbey, the results of this study
"could certainly serve as tremendous motivation for people concerned about
getting forgetful as they age, to get moving and try to stay fit."
Image source: Sofia Zhuravetc/Shutterstock