Normally people’s brains shrink by about 5% every decade after the age of 40 but this could be prevented.
Exercise increases brain size and so may help stop brain shrinkage with age, a study finds.
In some of the best evidence to date, exercise was shown to increase the size of the hippocampus, a brain structure critical for memory and other functions.
So far, studies have mostly shown the connection between exercise and brain size in rodents.
Shrinking brain size
Researchers followed people aged 24 to 76 for up to two years in a range of separate studies.
They looked at the effects of walking, cycling, treadmill running and general aerobic exercise.
Most people did around 2-5 sessions per week.
The results showed that left hippocampul volume was increased in people who exercised.
Dr Joseph Firth, the study’s first author, said:
“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.
Our data showed that, rather than actually increasing the size of the hippocampus per se, the main ‘brain benefits’ are due to aerobic exercise slowing down the deterioration in brain size.
In other words, exercise can be seen as a maintenance program for the brain.”
Preventing brain shrinking with age is possible
The study reviewed 14 separate clinical trials, including brain scans from 737 people.
This is some of the most definitive evidence yet published of the beneficial effects of exercise on brain health.
Normally people’s brains shrink by about 5% every decade after the age of 40.
Exercise is one of the few interventions proven to slow this process down.
The study was published in the journal NeuroImage (Firth et al., 2018).
