The researchers did a meta-analysis of 14 studies and examined the brain scans of 737 people before and after aerobic exercise programs or in control conditions. The subjects ranged in age from 24 to 76 with an average age of 66 and included both healthy participants as well as those with mild cognitive impairments (like Alzheimer’s) and those with a clinical diagnosis of mental illness (like depression and schizophrenia).
The exercise involved included stationary cycling, walking, and running on a treadmill, two to five times a week, for durations ranging from three to 24 months. The new study’s authors discovered that while exercise had no effect on total hippocampal volume, it significantly increase the size of the left region of the hippocampus in humans.
“When you exercise you produce a chemical called brain-derived neurotrophic factor (BDNF), which may help to prevent age-related decline by reducing the deterioration of the brain,” says lead author, NICM postdoctoral research fellow, Joseph Firth
Firth says that along with improving regular healthy aging, the results have implications for the prevention of aging-related neurodegenerative disorders such as Alzheimer’s and dementia.