A major breakthrough in the fight against Alzheimer’s has been announced, with a simple blood test able to detect the disease before symptoms appear.

Experts are calling it the “holy grail” and say it could give Australians access to treatment much earlier than ever before.

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At the new Centre for Alzheimer’s Research, some of Australia’s brightest scientific minds have unveiled the breakthrough blood test that can detect Alzheimer’s disease years before memory loss begins.

“I really describe this as the holy grail,” Health Minister Mark Butler said.

The test measures tiny proteins in the blood, markers that indicate Alzheimer’s. It’s 90 per cent accurate.

The life-changing new blood test. Credit: 7NEWS

“This is transformative in terms of how we’re going to test people, diagnose people,” Professor Emma Devenney from Neuroscience Research Australia said.

The breakthrough is expected to lead to earlier treatment and hopefully a cure.

“We’d like to study people in their 20s and 30s through, you know, looking after blood pressure, cholesterol, exercise, engagement in the community. You can modify such that you never develop Alzheimer’s disease,” Professor Matthew Kiernan from Neuroscience Research Australia said.

Half a million Australians are living with dementia, now the nation’s leading cause of death. Alzheimer’s accounts for two-thirds of those cases.

Theresa Flavin has Alzheimer’s. Credit: 7NEWS

Many are discovered too late, like 60-year-old Theresa Flavin.

“Thank goodness, you know, we’re making some progress here because the diagnosis process is so exhausting and so demoralising,” Flavin said.

Despite the excitement, the test isn’t available to the public just yet. It will be used for clinical trials with specialist referrals due within nine months.

Research is expected to take a few years before it becomes available as a Medicare item through general practitioners.

“Obviously I’d like to see it sooner rather than later,” Butler said.

The breakthrough could give families more time with those they love.