Brain health decreases with age, with the average brain shrinking by approximately five percent per decade after the age of 40.
Washington: Turns out, you don't have to turn to supplements to boost your brain power as according to a recent study, working up a sweat is enough.
Researchers from Australia's National Institute of Complementary Medicine at Western Sydney University and the Division of Psychology and Mental Health at the University of Manchester in the U.K. examined the effects of aerobic exercise on a region of the brain called the hippocampus, which is critical for memory and other brain functions.
Brain health decreases with age, with the average brain shrinking by approximately five percent per decade after the age of 40. Studies in mice and rats have consistently shown that physical exercise increases the size of the hippocampus but until now evidence in humans has been inconsistent.
The researchers systematically reviewed 14 clinical trials which examined the brain scans of 737 people before and after aerobic exercise programs or in control conditions.
The participants included a mix of healthy adults, people with mild cognitive impairment such as Alzheimer's and people with a clinical diagnosis of mental illness including depression and schizophrenia. Ages ranged from 24 to 76 years with an average age of 66.
The researchers examined effects of aerobic exercise, including stationary cycling, walking, and treadmill running. The length of the interventions ranged from three to 24 months with a range of 2-5 sessions per week.
Overall, the results showed that, while exercise had no effect on total hippocampal volume, it did significantly increase the size of the left region of the hippocampus in humans.
Lead author Joseph Firth said that the study provides some of the most definitive evidence to date on the benefits of exercise for brain health.
He noted that during exercise, a chemical called brain-derived neurotrophic factor (BDNF) is produced, which may help to prevent age-related decline by reducing the deterioration of the brain.
Firth added that along with improving regular 'healthy' ageing, the results have implications for the prevention of ageing-related neurodegenerative disorders such as Alzheimer's and dementia - however further research is needed to establish this.
Interestingly, physical exercise is one of the very few 'proven' methods for maintaining brain size and functioning into older age.
The study is published in the journal NeuroImage.