Groundbreaking discoveries about dementia

Attaining a higher level of education, having a strong grip, and keeping your brain active may decrease your likelihood of developing dementia in later life, according to the latest findings into dementia research in Australia.

Alternatively, being physically inactive, obese, or having high blood pressure in midlife may increase your risk of developing dementia.

These findings are backed by the latest scientific research into cognitive ageing and dementia. They form part of a new report, Cognitive ageing and decline: Insights from recent research, released this month by the ARC Centre of Excellence in Population Ageing Research (CEPAR) in collaboration with Neuroscience Research Australia (NeuRA).

We looked at some of the findings from the report and spoke to lead researcher Professor Kaarin Anstey about what they mean for preventing dementia and cognitive decline in Australia in the future.

New lifestyle risk factors
Among the most important findings made by Anstey and her colleagues is the identification of seven lifestyle risk factors for developing dementia. These risk factors were present in 50 per cent of dementia cases involved in their study:

  1. Physical inactivity: 18%*
  2. Midlife obesity: 17%*
  3. Low educational attainment: 15%*
  4. Midlife hypertension: 14%
  5. Depression: 8%*
  6. Smoking: 4%*
  7. Diabetes mellitus: 2%*

(*Proportion of dementia cases attributable to each of these risk factors)

Public awareness of these risk factors is important because they are modifiable, say the researchers. “If we can get people to be aware of these risk factors and change their lifestyles, we may be able to reduce the incidence of dementia in the future,” says Anstey.

To gauge public awareness about these risk factors for dementia in the Australian population and to develop strategies to prevent the condition, Anstey and the CEPAR team conducted a national survey. They found a gap in people’s knowledge, especially when it came to understanding the importance of having good vascular health.

“We found that there was quite good knowledge about mental activity — that was the protective factor that was being endorsed most often to the public,” says Anstey.

“People knew about eating fish, and doing crosswords and Sudoku as being protective, but only five per cent of people knew about the vascular risk factors for dementia, such as hypertension, obesity, and diabetes,” she says.

Resilience to dementia
There are gender-specific factors that predict how resilient to dementia you are likely to be and there are also factors common to both genders.

The CEPAR report shows that for women, the gender-specific factors that predict your likelihood of being more resilient to dementia are:

  • Living with someone
  • Being married
  • Having lower pulse pressure
  • Having a higher peak expiratory flow (maximum speed of expiration)
  • Having a faster walking time
  • Having a faster turning time
  • Volunteering more often

The only gender-specific factor that predicts your likelihood of being more resilient to dementia if you are a man is:

  • Displaying less depressive symptoms

Factors common to both genders include:

  • Being younger
  • Having a higher level of educational attainment
  • Having a stronger grip
  • Engaging in more cognitive activity

The cost of dementia in Australia
Dementia cost the Australian economy close to $9 billion in 2016. This figure is expected to increase to approximately $12 billion by 2025. In 2016, the Australian economy lost approximately $5.5 billion in foregone work hours, in which carers were required to provide care for Australians with moderate dementia.

Dementia is the second leading cause of death in Australia and the leading cause of disability in Australians over 65. It is estimated that 400, 000 Australians are currently living with dementia and this figure is expected to double in the next twenty years.

Still a lot of work to be done
While the new findings help to bring the picture of dementia and cognitive decline into clearer focus, there are still conundrums to be unravelled by the researchers, says Anstey.

“For example, we know that being obese when you are middle-aged is a risk factor for developing dementia in later life but none of the trials on statins [cholesterol lowering drugs] have shown to be beneficial,” she says.

Another puzzle for researchers is why obesity in midlife is a risk factor for developing dementia but obesity in later life isn’t.

“The messaging for risk factors is quite simple, but we actually think the mechanisms underlying cognitive decline are quite complex,” says Anstey.

These unanswered questions highlight the importance of further research into ageing to pinpoint more risk factors and to raise further awareness.

“We need to develop better diagnostic tests and assessments, increase community education to ensure risk factors attributed to dementia are better managed, and support carers to reduce carer distress in the broader community,” Anstey says.

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