Cognitive decline can lead to dementia, making improving cognition as you age key to prevention.
A clinical trial has shown an internet-delivered lifestyle intervention has resulted in significantly better cognition in older adults.
The team, led by Professor Henry Brodaty AO, Co-Director of UNSW's Centre for Healthy Brain Ageing (CHeBA), calculated a global cognition score from online tests that measured memory, reasoning and speed of information processing, and published their findings in Nature Medicine today.
The landmark trial, known as Maintain Your Brain, is the largest internet-based trial ever conducted to attempt to prevent cognitive decline and dementia.
The researchers recruited over 6000 participants aged 55-77 for the trial through the Sax Institute's 45 and Up Study, to target modifiable risk factors for dementia in general and Alzheimer's disease in particular. Participants were without dementia but carried at least two of the major risk factors for dementia.
Half of the participants received an active intervention which included personalised coaching in two to four modules - physical activity, brain training, nutrition or depression/anxiety - depending on their risk factors, while the control group received publicly available information. A Mediterranean diet with limited meat and dairy, an increase in moderate-vigorous intensity exercises and specific types of computerised brain training were among the changes that led to an improved cognition score.
The Maintain Your Brain trial provided participants with four key modules to follow: |
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| 300 minutes of moderate or 150 minutes of vigorous exercise weekly, plus strength and daily balance training. | A Mediterranean diet rich in plant foods and healthy fats, with limited meat and dairy. | Three 45-minute sessions weekly for 10 weeks, followed by monthly cognitive skill sessions. | Using a digital program designed to reduce anxiety and depression. |
The trial directly or indirectly tackled several of the 14 modifiable risk factors, reported by the Lancet Commission, accounting for approximately 45% of the risk of dementia.
The researchers say the findings have international significance.
This intervention is scalable with the potential for population-level roll out that may delay cognitive decline in the general community. We could essentially reduce worldwide dementia prevalence if this trial were implemented to the wider population.
Professor Henry Brodaty
Greatest benefit to date in preventing cognitive decline
The trial incorporated participants from metropolitan, rural and remote areas, and assessed an online lifestyle intervention to prevent cognitive decline over a three-year period, with follow ups done at the end of each year. The team split participants in two groups.
The trial specifically tested whether improving lifestyle behaviours can slow cognitive decline.
The outcome was a resounding yes - we can improve cognition over three years and therefore, likely enhance resilience to dementia.
Professor Henry Brodaty
"Both groups improved but the intervention group demonstrated the greatest benefit to date in a randomised control trial to prevent cognitive decline."
82 year-old Bowral resident Paddy Goldsmith, who participated in Maintain Your Brain, believes the trial has significantly benefited her and her husband Geoff. Together they have continued to adhere to the nutrition guidelines and found that the brain training improved their concentration.
"I continue to do weekly balance and strength training as well as online brain training, which I would never have done without the knowledge learned in the trial," says Paddy.
Evidence to support a tailored prevention program
The findings recommend personalising prevention efforts and suggest that interventions focused on just one modifiable risk factor, for example physical inactivity, are less effective in preventing dementia.
"Previous trials have largely not tailored interventions to match dementia risk factors of individual participants," says Prof. Brodaty. "Our findings suggest personalising interventions and targeting a broad range of lifestyle factors are important for success."
Chair of CHeBA's Advisory Committee, Ita Buttrose AC OBE, says this is a moment to be celebrated.
"We now have clear evidence to support a national dementia prevention program," says Buttrose. "Previously Australia has been a leader in prevention, particularly with smoking, skin cancer and HIV minimisation, but we have dropped the ball. Dementia is a prime example of where we can and must act now.
"This evidence demonstrates significant benefits to improving cognition and potentially delaying the onset of dementia.
It is now time for Australia to think seriously about long term goals, to acknowledge the evidence and embrace the need for investment in prevention.
Ita Buttrose AC OBE
Findings may be even more significant
The estimate of the intervention effect is considered conservative, given the control group and the group that received personalised coaching both improved.
Through assessing self-reported change from baseline to the year three follow up, researchers also noted significant improvements in aerobic activity, strength training, diet and depression scores.
"If we were able to compare the intervention with a control group that received no information at all, we would likely find out that the benefits of this trial would be even greater," says Prof. Brodaty. "Participants aged 55-65 showed greater benefit than those aged 66-77, suggesting we should consider starting prevention programs earlier."
This trial has several strengths, particularly in terms of the large population sample size and methodology. Limitations exist, including that participants were more likely to have university education, better self-rated quality of life and a family history of Alzheimer's disease. There was also a lack of ethno-racial diversity among participants.
Prof. Brodaty says this research offers new hope for prevention of dementia.
"Future developments could focus on cultural adaptation, particularly targeting groups from lower socio-economic backgrounds and those with less education."
The intervention modules were: |
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