Australian scientists believe they've found an association between high levels of iron in the brain and the progression of Alzhiemer's disease.

Australian researchers say they've made a breakthrough in Alzheimer's research that points towards a potential new therapy to slow, if not stop, the progression of the brain disease.

Scientists at the Florey Institute of Neuroscience and Mental Health and the CSIRO have for the first time shown an association between higher levels of iron in the brain, the presence of the Alzheimer's protein known as amyloid with poorer memory and language skills.

It's long been known a build up of amyloid in the brain determines whether people will eventually experience Alzheimer's disease.

Analysis of MRI brain scans of 117 participants of the Australian Imaging and Biomarker lifestyle study now suggests the presence of high levels of iron in the hippocampus acts together with amyloid to speed up the disease's progression.

"Cognitive abilities like short-term memory, executive function and language ability declined much faster in people with brain iron levels and high amyloid levels even if they were otherwise healthy, than those with low brain iron who were also amyloid positive," said co-lead investigator Dr Scott Ayton.

"Those individuals with high amyloid but low iron will also eventually go on to develop Alzheimer's disease, but much later than their high-iron counterparts," added Dr Ayton.

As a result of the findings, published in journal Brain a drug trial will begin in Australia later this year.

Scientists will use existing drug, deferiprone, to "mop-up" the excess iron in the brain to see if it slows down the progression of the disease.

Professor Ashley Bush at the Florey Institute says if the 3D trial proves iron slows disease progression then it's likely in the future doctors will be better able to predict the onset of Alzheimer's and begin therapy sooner.

"We imagine a future where your GP sends you off for your 60-year health check, including a brain iron MRI scan, which is quick, cheap and painless," Professor Bush said.

* Newly diagnosed dementia patients or those aged 65 who have noticed their memory declining can register to be involved in the study at 3D@florey.edu.au.