BDNF mediates improvements in executive function following a 1-year exercise intervention.

Area of Science:

• Neuroscience
• Gerontology
• Exercise Physiology

Background:

• Cognitive decline, particularly in executive function, is a common aspect of aging.
• Brain-derived neurotrophic factor (BDNF) levels also decrease with age and are linked to cognitive function.
• Aerobic exercise is a potential intervention to mitigate age-related cognitive decline.

Purpose of the Study:

• To investigate if brain-derived neurotrophic factor (BDNF) mediates the relationship between a 1-year walking intervention and executive function in older adults.
• To explore the moderating role of age in the effects of exercise on BDNF levels and executive function.

Main Methods:

• A 1-year randomized controlled trial involving 90 older adults (mean age 66.82).
• Participants were assigned to either a moderate-intensity walking group or a stretching and toning control group.
• Measures included serum BDNF levels and performance on a task-switching paradigm at baseline and follow-up.

Main Results:

• Age moderated the intervention's effect on BDNF levels; older participants (highest quartile) showed the greatest BDNF increase with walking.
• Brain-derived neurotrophic factor (BDNF) mediated the intervention's effect on task-switch accuracy.
• This mediation was age-dependent, occurring only in participants over 71 years old.

Conclusions:

• Aerobic exercise interventions can increase BDNF levels in older adults, particularly the oldest.
• Exercise-induced BDNF increases can improve executive function (task-switching accuracy) in older adults, specifically those over 71.
• Age and BDNF are critical factors in understanding how exercise impacts cognitive function in the elderly.