Early warning offers hopes of staving off Alzheimer’s

Alzheimer's disease could be detected years ahead of time using a newly discovered blood biomarker, potentially giving elderly Australians valuable time to mitigate the decline.

The Australian Institute of Health and Welfare estimates there are 83 per 1000 Australians aged over 65 with dementia, of which Alzheimer’s is the most common cause. Picture: Matt Rourke

Alzheimer's disease could be detected years ahead of time, potentially giving elderly Australians and their doctors valuable time to mitigate the decline, new research has found.

Scientists at Macquarie University and the CSIRO have discovered a relationship between a blood biomarker and that individual’s risk of cognitive impairment in several years.

“Someone with increased levels of 3-HAA is 35 times more likely to progress to Alzheimer’s than someone with normal levels,” Macquarie Medical School’s David Lovejoy, team leader, said.

The discovery could open the door to systematic screening and early detection. It may also lead to the development of a simple blood test instead of a costly and complex diagnosis years down the line, giving patients valuable time to make steps to stave off the crippling disease.

Lifestyle changes to this end include a Mediterranean diet, getting at least half an hour of cardiovascular exercise a day, and reducing alcohol consumption.

However, Dr Lovejoy warned it was not yet known if lifestyle changes – despite being known to reduce chronic inflammation – would be able to altogether reverse cognitive decline.

“That is something that needs more research, but there are so many exciting possibilities here,” he said.

The Australian Institute of Health and Welfare estimates 83 out of every 1000 Australians aged over 65 have dementia, of which Alzheimer’s disease is the most common cause. It is estimated Australia’s ageing population will see the number of people with dementia double to 849,300 by 2058 compared to 386,000 in 2021.

The Macquarie University and CSIRO study is based on data from the Australian Imaging Biomarkers and Lifestyle Study of Ageing, a CSIRO project launched in 2006 that has more than four years of longitudinal data on over a thousand elderly Australians to study the development of Alzheimer’s disease.

The study found that the people whose blood samples contained elevated levels of the 3-HAA blood biomarker were far more likely to develop Alzheimer’s disease or mild cognitive impairment in several years’ time compared to people otherwise.

“We found there were very profound differences … 3-HAA dramatically increased the risk,” Dr Lovejoy said. “Every point increment above [average], you’re 35 times more likely to develop Alzheimer’s or mild cognitive impairment.”

The 3-HAA blood biomarker is indicative of chronic inflammation of the neurological system, the study said. That underlying inflammation, in turn, is understood to be one of the key culprits in causing Alzheimer’s disease.