What do we know about dementia?
Recently Associate Professor Michael Valenzuela spoke at Macquarie University’s Australian Advanced School of Medicine about his work with elderly Australians. Associate Professor Venezuela leads a team of researchers at the Brain and Mind Research Institute, part of the University of Sydney. His work is important for determining how elderly people can be productive into old age rather than being confined to institutions or nursing homes. Dementia is not one disease, but a collection of diseases characterised by a decline in brain functions, such as perception, memory, language and cognitive skills1. Research has shown that shrinkage of the hippocampus (a brain section important for memory and spatial skills) is an indicator for dementia (Figure 1)2.
What are the risk factors?
So what determines whether an elderly person can maintain an independent lifestyle or become dependent on others for care and support? A major risk factor for dementia is being mentally lazy. A person’s cognitive lifestyle across the years of their life is a major factor in the risk of cognitive decline and developing dementia as a person ages. A survey of elderly people in Australia, the UK, the USA and France (Lifetime of Experience Questionnaire) is currently being conducted to find out more about how cognitive lifestyle correlates with risk of dementia3.
One recent finding of the Lifetime of Experience Questionnaire is that managerial experience during a person’s working life is correlated to a bigger hippocampus. Managing at least 10 people can be effective at preventing the onset of dementia4. The researchers analysing the data have postulated that interactions with people and the complex skill set required to successfully perform in a management position are what leads to this reduction in dementia risk.
What can we do to stave off the onset of dementia?
The findings from Associate Professor Valenzuela’s research show that one way to reduce the risk of dementia is to maintain an active cognitive lifestyle (ACL)5. Consistently ‘working out’ your brain can increase the time you live with a clear mind and reduce the amount of time living with dementia6. This pushing back of the onset of dementia is known as compression of cognitive morbidity. Pablo Picasso is a wonderful example of a person who was active and independent into old age. He continued to paint right up to his death at 73 years old (Figure 2).
How do we go about promoting active cognitive lifestyles in communities?
Associate Professor Valenzuela’s team has started a Brain Training Lab at the Montefiore Home in Randwick, Sydney (Figure 3). Here the program participants undergo computer-assisted cognitive training for 60 minutes, three times a week over a 12 week program. There are two groups – one does repeated standardized tasks and the other group watches National Geographic videos and answers questions about them. This study aims to answer questions about the minimum/maximum amount of training required to improve cognitive function and how long positive effects from brain training can last7.
Another experiment that has been established is the Study of Mental Activity and Regular Training (SMART) trial. This study combines mental and physical training to see if either type of training in isolation or the combination of both improves cognitive abilities8. The link between exercise and brain health has been observed in rat experiments. Exercise has been shown to improve brain organisation and object/place recognition in aged rats. This link has also been demonstrated in humans; exercise training has been shown to increase the size of the hippocampus9. The SMART study includes 100 Sydneysiders over the age of 55 and they conduct training twice a week for six months. Measurements of cognitive ability before any training, after six months of training and at an 18 month follow-up hope to determine if there are improvements in the brain, general health and quality of life of the participants8.
Only in the past 100 years have people been able to live beyond 65 years of age. The population of the world is aging fast due to the maturing of the baby boomer generation and medical advancements extending life expectancy. The combination of aging populations and increased life expectancy means more people than ever before are soon going to be retired. Retirement design needs to be carefully considered so the development of dementia in aging population doesn’t negatively impact on the economy and health care systems10. Studies on aging and cognitive ability have shown that it isn’t effective to retire and then do no ‘brain work’ for 20-30 years. Associate Professor Valenzuela warns that retirement design needs to take this into account. Opportunities need to be created where elderly people can replace the intensive cognitive and social interactions of a work environment when they retire. Only in this way can the older people retain their cognitive abilities and stave off the onset of dementia.
Want to learn more?
- Department of Health, Commonwealth of Australia (2013). Dementia, http://www.health.gov.au/dementia, accessed 23 May 2014.
- Thompson PM, Hayashi KM, de Zubicaray GI, Janke AL, Rose SE, et al. (2004). Mapping hippocampal and ventricular change in Alzheimer disease. NeuroImage, 22(4), 1754-1766. doi: 10.1016/j.neuroimage.2004.03.040.
- Valenzuela M & Sachdev P (2007). Assessment of Complex Mental Activity Across the Lifespan: Development of the Lifetime of Experiences Questionnaire. Psychological Medicine, 37, 1015-1026. doi: 10.1017/S003329170600938X.
- Suo C, Leon I, Brodaty H, Trollor J, Wen W, et al. (2012). Supervisory experience at work is linked to low rate of hippocampal atrophy in late life. NeuroImage, 63, 1542-1551. doi: 10.1016/j.neuroimage.2012.08.015.
- Marioni RE, van den Hout A, Valenzuela MJ, Brayne C, Matthews FE, et al. (2012). Active cognitive lifestyle associates with cognitive recovery and a reduced risk of cognitive decline. J Alzheimers Dis, 28(1), 223-230. doi: 10.3233/JAD-2011-110377.
- Marioni RE, Valenzuela MJ, van den Hout A, Brayne C, Matthews FE (2012).Active Cognitive Lifestyle Is Associated with Positive Cognitive Health Transitions and Compression of Morbidity from Age Sixty-Five.PLoS ONE, 7(12), e50940.doi: 10.1371/journal.pone.0050940.
- Lampit A, Suo C, Gates N, Kwok SSY, Naismith S et al. (2011). Temporal evolution of cognitive training-induced structural and functional brain plasticity. 10th National Emerging Researchers in Ageing Conference, University of New South Wales, Sydney. http://rng.org.au/timecourse/, Accessed 23 May 2014.
- Gates NJ, Valenzuela M, Sachdev PS, Singh NA, Baune BT, et al. (2011) Study of Mental Activity and Regular Training (SMART) in at risk individuals: A randomised double blind, sham controlled, longitudinal trial. BMC Geriatrics, 11(19), doi: 10.1186/1471-2318-11-19.
- Erickson KI, Voss MW, Prakash RS, Basak C, Szabo A, et al. (2011). Exercise training increases size of hippocampus and improves memory. Proceedings of the National Academy of Sciences of the United States of America, 108(7), 3017-3022. doi: 10.1073/pnas.1015950108.
- Brookmeyer R, Johnson E, Ziegler-Graham K & Arrighi HM (2007). Forecasting the global burden of Alzheimer’s disease. Alzheimer’s & Dementia, 3(3), 186–191. doi: 10.1016/j.jalz.2007.04.381.