TARGETING lifestyle risk factors for dementia that occur throughout life may help to reduce the incidence of the condition by up to one-third, says an Australian expert.
In a Viewpoint published in JAMA Neurology, Professor Graeme Hankey, Professor of (Neurology) Medicine at the University of Western Australia, wrote that epidemiological studies in Australia and the UK had pinpointed up to nine modifiable lifestyle risk factors – low levels of education; midlife hearing loss; physical inactivity; hypertension; type 2 diabetes; obesity; smoking; depression; and social isolation – that contributed to the development of dementia throughout the course of life.
“The implications are that successful modification or elimination of these risk factors through increasing childhood education; managing midlife hearing loss, hypertension and obesity; and maintaining physical activity and social engagements, reducing or stopping smoking, and managing depression and diabetes in later life could reduce or delay dementia incidence by up to one-third,” Professor Hankey wrote.
He said that positive results from the Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) study – a 2-year randomised clinical trial of a multidomain intervention addressing diet, exercise cognitive training, social stimulation, and management of vascular and metabolic risk factors – suggested that public health interventions may be employed to decrease the risk of dementia.
However, Professor Hankey noted, a causal link and generalisability were yet to be established, and efforts were underway in various regions – including the United States, Europe, Singapore and Australia – to further understand the associations.
A pilot project for Australia’s contribution to this international effort – the Maintain Your Brain trial – is now underway, with the trial expected to start in April 2018. The 4-year randomised controlled trial will investigate the cognitive impact of a multimodal targeted intervention, which will be delivered online.
Professor Henry Brodaty, trial leader and co-director of the Centre for Healthy Brain Ageing at the University of NSW, said that the trial aimed to enrol 16 000 people from the 45 and Up Study cohort.
Participants will be assigned to either an information arm (where they will be provided with static information to help them improve lifestyle measures) and a coaching arm (where they will receive more intensive coaching to support them in shifting their behaviours).
Professor Brodaty said that the program was targeting people aged 56–76 years, which he described as the “sweet spot” for intervention.
“People [in this age range] are young enough not to have accumulated too much Alzheimer’s or vascular pathology in the brain, but are old enough to be at risk of cognitive decline,” he said.
Professor Brodaty said that the goal of the trial was to develop an individualised, online platform that could be rolled out nationally, and perhaps internationally.
“That’s the beauty of this program,” Professor Brodaty told MJA InSight. “If we can show that it works, it’s eminently scalable.”
Professor Nicola Lautenschlager, chair of Old Age Psychiatry at the University of Melbourne, welcomed research efforts to design a multidomain intervention to tackle the modifiable risk factors for dementia.
“There are lots of challenges, but the proof of concept demonstrated by the FINGER trial is very exciting,” she said. “It sends a very good message to the population that everybody can do something about their dementia risk. At middle age, if people start thinking – am I active enough, do I carry too much weight, have I regular appointments with my GP, and am I socially and cognitively engaged – it would be great.”
Professor Lautenschlager said that significant challenges around shifting people’s behaviour remained, pointing out that the FINGER trial required a significant time commitment from participants.
“The FINGER trial used a multidomain intervention where you had to do a lot of things – go to the gym, do cognitive training, change diet, and regularly see doctors. It’s very demanding, even for a very motivated person,” she said.
Also, she said, findings from two subsequent European trials – the Prevention of Dementia by Intensive Vascular Care (PreDIVA) trial, and the Multidomain Alzheimer Preventive Trial (MAPT) – were negative.
Dr Terence Chong, psychiatrist and research fellow at the Academic Unit for Psychiatry of Old Age at the Department of Psychiatry, University of Melbourne, said that mounting evidence to suggest that lifestyle modification could reduce dementia risk was “quite exciting”, although he agreed that results from the preDIVA and MAPT trials had “quelled some of the excitement” from the FINGER findings. However, he added, indirect evidence had shown that improved lifestyle measures may be responsible for a slight reduction in dementia incidence over the past few decades.
Dr Chong said that while the jury remained out on causality, lifestyle interventions could provide broader health benefits for patients, regardless of their impact on dementia.
“Lifestyle interventions are going to be beneficial for our health in lots of different ways, even if it’s not yet definitively proven for dementia,” he said. “In the absence of a cure or effective treatment for Alzheimer’s, I think that this is the direction we need to be heading in.”
Dr Chong added that, in his clinical practice, patients and their families appreciated knowing that there were steps they could take to potentially reduce their risk of dementia, and he often referred them to a risk calculator developed by the Australian National University.
Professor Brodaty said that efforts to find a drug treatment for Alzheimer’s disease, the main cause of dementia, had been unsuccessful to date.
“We can’t wait for the silver bullet to come. We know that if we can delay onset of dementia by 2 years, there is a 20% reduction in prevalence, and if we can delay by 5 years, a 50% reduction in prevalence. And the benefits [of lifestyle interventions] are not just for the brain; there are benefits for the heart, for blood pressure, for muscle strength, for bone strength and for mood,” Professor Brodaty said, adding that the Maintain Your Brain trial would measure these factors as secondary outcomes.
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