A study has shown that regular brisk walks can slow down the loss of mental ability that is associated with old age, and while it’s not being considered as a cure for Alzheimer’s, it appears that such aerobic exercise could at least delay and slow the onset of dementia.
A group of 120 men and women aged 60 – 80 agreed to take part in a study to test the benefits of physical exercise at the University of Pittsburgh. All participants confessed to doing little or no exercise in their daily lives before the experiment began.
Over the course of a year, half undertook closely supervised aerobic exercise, walking around a track for 40 minutes a day, three times a week. The other half of the group spent the same time stretching, doing light weight training and mild yoga.
MRI scans were used to measure the size of the various areas of the brain before the intervention, after six months, and at the end of the one-year study.
The walking group demonstrated a 2% – 3% increase in the size of the hippocampus and prefrontal cortex, enough to offset and reverse the shrinkage that doctors expect to see among this age group.
‘It may sound like a modest amount but that’s actually like reversing the age clock by about one to two years,’ said neuroscientist Professor Kirk Erickson, who announced his findings at the annual meeting of the American Association for the Advancement of Science last Sunday.
Memory tests were conducted for all participants at the three intervals. Those in the aerobic exercise group showed improved memory function, when measured against their performance at the start of the study, an improvement associated with the increased size of the hippocampus.
‘The prefrontal cortex is really involved in a lot of higher level cognitive functions and the hippocampus is well known to be involved in memory formation, and when it shrinks it leads to Alzheimer’s disease and dementia’ said Professor Erickson.
‘People are misled to believe they need years of vigorous physical exercise. But it only needs to be moderate and not even for that long’ he said. Whilst pointing out that his team had not yet pin-pointed the cause of the increased size of brain areas, he said he thought it might be to do with the increased blood flow or an increase in the number of neurones or other kinds of brain cells.
‘The results suggest that brain and cognitive function of the older adults remain plastic and highly malleable. There is not this inevitable decline that we used to think there was. We can improve brain function by relatively modest amounts of physical activity,” said Kirk Erickson of the University of Pittsburgh in Pennsylvania.