The Dementia Collaborative Research Centre: Early Diagnosis and Prevention (DCRC-EDP) is undertaking several research projects focussing on prevention of dementia.  Other Australian researchers are also doing important work in this area.

Literature reviews of dementia risk factors

Sometimes there are several published research studies investigating a particular question that have conflicting findings.  For example, in studies investigating the relationship between having high cholesterol and developing dementia, some might find that high cholesterol increases the risk of dementia, some might find no relationship between the two, and some might find that having high cholesterol reduces the risk of dementia.

What is needed to properly understand the relationship between cholesterol and dementia is to review all the studies, investigate the reasons for the different findings, and come to a conclusion based on all the published data rather than on just one study.  These reviews are extremely important for establishing the nature of the influence of a factor like cholesterol on the risk of developing dementia.

In recent years Professor Kaarin Anstey and colleagues at the Australian National University and Dr Michael Valenzuela and colleagues at the University of New South Wales have undertaken and published several important reviews of the literature on dementia risk factors.  Further reviews of additional risk factors are currently underway.

• Anstey et al. Alcohol consumption as a risk factor for dementia and cognitive decline: meta-analysis of prospective studies. American Journal of Geriatric Psychiatry, 2009, 17(7):542-555.
• Anstey et al. Cholesterol as a risk factor for dementia and cognitive decline: a systematic review of prospective studies with meta-analysis. American Journal of Geriatric Psychiatry, 2008, 16:343-354.
• Anstey et al. Smoking as a risk factor for dementia and cognitive decline: a meta-analysis of prospective studies. American Journal of Epidemiology, 2007, 166(4):367-378.
• Valenzuela MJ, Sachdev P. Brain reserve and dementia: a systematic review. Psychological Medicine, 2006, 36:441-454.
• Valenzuela MJ, Sachdev P. Brain reserve and cognitive decline: a non-parametric systematic review. Psychological Medicine, 2006, 36(8):1065-1073.

Modelling the impacts of dementia prevention interventions

With the results of literature reviews that provide information about how much a factor influences dementia risk, Professor Laurie Brown and colleagues at the University of Canberra are developing computer models to investigate the potential impacts of interventions to modify risk factors.  For example, they have estimated that if we could reduce physical inactivity rates by 5% per year, this would reduce the number of people with dementia in 2050 by 11%.  However, if the number of Australians who are physically inactive continues to grow, there would be a larger than expected increase in the number of people with dementia.

These models can also investigate the potential economic savings of health interventions to reduce dementia risk factors in the Australian population.  This work is very important for helping to establish the likely outcomes of implementing dementia prevention strategies and prioritizing the risk factors that may have the greatest impact.

Developing and evaluating education resources for the community and for health professionals

Awareness of dementia risk factors and the potential for dementia risk reduction among the Australian community is low.  Public surveys reveal that only around half of Australian adults believe it is possible to reduce the risk of dementia.  Education is therefore an extremely important part of the effort to increase risk reduction behaviours.  And that is of course what Mind your Mind is all about.

Alzheimer’s Australia and our DCRC-EDP colleagues are using Mind your Mind, this website and other resources to educate the community and health professionals about dementia risk reduction.  In the coming phase of this work, we plan to implement interactive checklists for people to think about their dementia risk and embark on their own risk reduction program.  We will also develop education resources for health professionals including online training modules and education courses.  The effectiveness of these strategies in increasing knowledge and changing behaviour will be evaluated so that we can learn what works well and improve our approaches to dementia prevention.

Trials of dementia prevention strategies

The Study of Mental Activity and Resistance Training (SMART Trial) aims to determine whether increased mental and physical activity can prevent cognitive impairment or dementia.  It is being conducted by leading ageing and exercise researchers in Sydney.

The SMART Trial involves older individuals with borderline cognitive abilities and therefore at risk of developing dementia.  Participants complete supervised cognitive and/or physical training for six months and undergo longitudinal outcome measures 12 months later.  The study will test whether any benefits to mental function are a result of changes in brain structure and function, body metabolism, biochemistry and immune function.

Other Australian researchers are also developing plans for intervention trials to test the effectiveness of dementia prevention strategies.

Early diagnosis of dementia

The Australian Imaging Biomarkers and Lifestyle Flagship Study of Ageing (AIBL) aims to improve our understanding of the causes of Alzheimer's disease, and help develop improved diagnostic methods and preventative strategies.  It is a longitudinal study of ageing involving over 1000 volunteers with Alzheimer's disease (AD), Mild Cognitive Impairment (MCI) and healthy older people.  The study is being conducted by leading Alzheimer’s researchers in Melbourne and Perth

The study involves cognitive testing, blood tests, brain imaging and measures of lifestyle such as diet and levels of physical activity.  It will help researchers develop and confirm diagnostic markers of Alzheimer’s disease that can be used to diagnose dementia early and monitor disease progression.  The researchers will also develop hypotheses about diet and lifestyle factors that might delay the onset of dementia.  This will enable studies that may lead to clinically proven preventative strategies for Alzheimer's disease to be designed and conducted.

For further information, visit the AIBL website.