The hippocampus shrinks in late adulthood, leading to impaired memory and
increased risk for dementia. Hippocampal and medial temporal lobe volumes
are larger in higher-fit adults, and physical activity training increases
hippocampal perfusion, but the extent to which aerobic exercise training can
modify hippocampal volume in late adulthood remains unknown. Here we show,
in a randomized controlled trial with 120 older adults, that aerobic
exercise training increases the size of the anterior hippocampus, leading to
improvements in spatial memory. Exercise training increased hippocampal
volume by 2%, effectively reversing age-related loss in volume by 1 to 2 y.
We also demonstrate that increased hippocampal volume is associated with
greater serum levels of BDNF, a mediator of neurogenesis in the dentate
gyrus. Hippocampal volume declined in the control group, but higher
preintervention fitness partially attenuated the decline, suggesting that
fitness protects against volume loss. Caudate nucleus and thalamus volumes
were unaffected by the intervention. These theoretically important findings
indicate that aerobic exercise training is effective at reversing
hippocampal volume loss in late adulthood, which is accompanied by improved
memory function.
Proc Natl Acad Sci U S A. 2011 Feb 15;108(7):3017-22. Epub 2011 Jan 31.