Being physically active can keep you fit and lift your mood, but might aerobic exercise also help delay or reduce dementia risk?
A new study involving Trinity College Dublin is recruiting relatively sedentary people aged over 50 with mild memory problems.
Participants in the year-long study will be divided into groups: one group does regular aerobic exercise, one does regular toning and stretching, and a control group does no prescribed exercise.
Various strands of evidence suggest that physical activity could reduce the risk or delay the onset of dementia, according to consultant psychiatrist Prof Brian Lawlor, one of the principal investigators on the study. One strand is the link between physical activity and brain structure and function.
“Physical activity, and particularly aerobic exercise – where you increase the heartbeat – lifts mood and improves spatial learning and memory and attention. And in older people who do not have memory impairment, studies show that, over time, aerobic exercise can increase the size of the hippocampus, which is important for spatial and short-term memory.”
He says studies suggest that people who report having been sedentary in midlife have an increased risk of dementia later. Also, people who report having been active in midlife tend in later life to have fewer physical hallmarks in the brain associated with dementia.
It seems to make sense that exercise could help reduce dementia risk by keeping our hearts and blood vessels healthy and by keeping blood pressure and diabetes in check, but it is hard to pin down any specific cause and effect, says Lawlor.
“There could be something else mediating this, and that is why we want to look specifically at exercise in our research.”
The new study, which is being carried out in Ireland, Germany and the Netherlands and funded under the EU Joint Programme on Neurodegenerative Disease Research, is looking for people over the age of 50 to take part. “We want people to contact us if they are relatively sedentary and feel their memory is less than it should be but they are still functioning independently,” says Lawlor.
Potential participants will be screened over the phone initially, and the researchers will liaise with the candidates’ GPs and carry out an exercise test to ensure they can take part.
The initial exercise sessions will take place three times a week, with two supervised sessions at St James’s Hospital in Dublin, then participants will be supervised once at week at St James’s and twice a week unsupervised at home by themselves. All participants – including those who are not attending the exercise sessions – will take tests to monitor their cognition, physical fitness and quality of life at points during the study.
In the meantime, Lawlor stresses there are never guarantees, but he suggests some general rules for protecting brain health. "No smoking, cut alcohol, get the blood pressure under good control – all these things can make a difference.
"And exercise does seem to be linked to better brain health, so I would recommend to anyone in midlife that they avoid a sedentary lifestyle and exercise three times a week. It doesn't have to be in a gym; you could go for a brisk walk."
- For more information, phone 085-2239249 or email neuroexercise@tcd.ie
