Doing physical exercise could help to lower the chances of developing dementia.
This is even the case for those whose genes make them more at risk of contracting the disease, according to new research from the University of Maryland in the US.
The findings showed how regular exercise helped to increase the brain's health and prevent the hippocampus from shrinking.
Even those who had the APOE-e4 gene, which increases the chance of developing the disease, could lower the likelihood of contracting the condition with physical activity three or more times a week.
Scientists measured the size of the hippocampus in four sets of pensioners aged between 65 and 89 at the beginning and end of the study.
The groups were divided based on whether their exercise rate was high or low and if they had the gene or not.
It transpired the only set that experienced the size of the hippocampus decreasing was those who did not exercise frequently and had the gene.
The other three sets maintained the size of this part of the brain, including the group of pensioners that had the APOE-e4 gene.
Kinesiology researcher Dr Carson Smith, who conducted the study, said: "The good news is that being physically active may offer protection from the neurodegeneration associated with genetic risk for Alzheimer's disease."
"We found that physical activity has the potential to preserve the volume of the hippocampus in those with increased risk for Alzheimer's disease, which means we can possibly delay cognitive decline and the onset of dementia symptoms in these individuals."
However, he commented how these findings necessitated additional research to determine how exercise and genetics worked together to reduce the risk of contracting dementia.
The research is published in full in the journal Frontiers in Aging Neuroscience.
Around 800,000 people in the UK have been diagnosed with dementia. In excess of one-third of those over the age of 65 expected to develop the condition in the future.
Find out about dementia care and support services at Barchester care homes.