A study of the brains of mice shows that structural deterioration associated with old age can be prevented by long-term aerobic exercise starting in mid-life. Old age is the major risk factor for Alzheimer’s disease, like many other diseases, as the authors at The Jackson Laboratory in Bar Harbor, Maine, note.
Age-related cognitive deficits are due partly to changes in neuronal function, but also correlate with deficiencies in the blood supply to the brain and with low-level inflammation.
“Collectively, our data suggests that normal aging causes significant dysfunction to the cortical neurovascular unit, including basement membrane reduction and pericyte (cells that wrap around blood capillaries) loss. These changes correlate strongly with an increase in microglia/monocytes in the aged cortex,” said Ileana Soto, lead author on the study.
However, the researchers found that if they let the mice run freely, the structural changes that make the blood-brain barrier leaky and result in inflammation of brain tissues in old mice can be mitigated. That suggests that there are also beneficial effects of exercise on dementia in humans.