Regular exercise can improve brain function by up to 15%: Study

‘For older people in the community, their greatest fear used to be cancer – not the economy, not the pollution, not global warming. Now, it’s dementia. People are terrified.’
 
That is what Scientia Professor Henry Brodaty, co-director of the Centre for Healthy Brain Ageing, recently told newsGP.
 
While scientists have yet to find a magic bullet for cognitive decline, what if social prescribing of physical activity could, at the very least, delay its onset?
 
Those are the conclusions  of a recent study by University of Queensland researchers.
 
The study drew on longitudinal data from the Survey of Health, Ageing and Retirement in Europe (SHARE) involving 16,700 people aged 54-75 over the course of 13 years. The data showed a clear link between regular exercise and improved cognitive function – and the effect was particularly evident for women.
 
Weekly moderate physical activity increased people’s cognitive function on average by 5% for men and 14% for women.
 
A combination of moderate and vigorous physical activity each week saw the positive effect on cognition increase even further, to 8% for men and 15% for women.
 
Lead author, PhD candidate Sabrina Lenzen told newsGP that while she expected to see some positive effect, the degree of improvement was surprising.
 
‘If a person scores 12 out of 20 in their cognitive function test and then started doing regular moderate exercise, we could see scores increase to 12.6 for men and 13.7 for women,’ she said.
 
‘That was quite surprising, especially because studies so far often see the correlation of physical activity on cognition [as due] to vascular improvement.
 
‘But we actually see the improvement through physical activity, rather than physical activity improving your vascular health, and that's why your cognition improves.’
 
Examples of moderate physical activity include going for a brisk walk, while vigorous activity might be running or circuit training.
 
For healthy adults aged 18-64, the World Health Organization recommends at least 150 minutes of moderate-intensity physical activity or 75 minutes of vigorous-intensity activity per week. However, just 15% of Australian adults meet the physical activity guidelines.
 
Ms Lenzen says the research adds to the evidence around addressing modifiable risk factors for dementia, and emphasises the importance of social prescribing.
 
‘If we can start a broader prevention program [on] prescribing physical activity, that would be really beneficial,’ she said.
 
‘It's just a question now of how to do it so that people actually will follow that advice, [because] just telling someone to be more active is always a bit tricky.
 
‘So if we can actually get some more tailored physical activity programs that will be ideal.’
 
Study co-author and PhD supervisor Professor Brenda Gannon agrees, and says GPs have a critical role to play in getting the message out to patients.
 
‘Exercise is one of the mechanisms that GPs can use in their social prescribing, alongside other things like, for example, volunteering or even brain training exercises,’ she told newsGP.
 
‘While our study has these findings, not everybody's going to read it. So it's important that the word gets out there via primary care physicians. We need to go and target those who we might say have an unmet need; they might not even realise they need to exercise more.
 
‘So that's where the social prescribing could be quite useful.’
 
Professor Gannon says encouraging people to build movement into their daily lives can be helpful.
 
‘Some will say “where will I get that hour in the day?” It could be walking, and that can include your walk to the bus or walking up the stairs at work,’ she said.
 
‘[For] those who may suffer from obesity or diabetes, we're not expecting people to go out and run crazy – we're talking about a brisk walk, regularly, three times a week.’
 
While the study was limited to people aged 54-75, Professor Gannon says the focus on physical activity should in fact start much earlier.
 
‘It’s okay to start at 50, but actually, it's a life span issue. I can imagine it must be extremely hard if you were 50 and given a prescription of exercise rather than the prescribing beginning when you're younger,’ she said.
 
‘If we had done this study using information on people aged 30, 40 plus, I'm sure we would have found similar effects. So it's never too early to start.’
 
From a policy perspective however, both Ms Lenzen and Professor Gannon agree more needs to be done.
 
‘It's quite important to have public health campaigns in terms of having the facilities close to people,’ Professor Gannon said.
 
‘We’ve seen it this year, particularly in the COVID crisis. It's important that we can actually get out and walk within our own areas, not just way off at the beach or a park that could be 20 kilometres away.’
 
Currently, more than 300,000 Australians live with dementia. That’s expected to rise to 900,000 by 2050, which is estimated to cost an estimated $6 billion in healthcare and lost productivity.
While scientists continue their efforts to find a cure, Professor Gannon says incorporating healthier habits can both improve quality of life and also be cost effective.
 
‘If we can slow down that cognitive decline for people, it might prevent them from getting dementia. But if it doesn't, at least they've had a longer decline into it and might enjoy a better quality of life,’ she said.
 
‘Also, it's important in terms of cost efficiency for the healthcare system. People with dementia need a lot of care.
 
‘If we can slow down the process and have less people needing the high end facilities then I think that will be a benefit not only for the people but also for the economy and the health system.’

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cognitive function dementia physical activity social prescribing