Dr Gillings, who was appointed to his position by UK British Prime Minister David Cameron on behalf of the Group of Seven major advanced economies in February, is visiting Australia to meet ministers, officials, researchers and patient advocates.

During his visit to Canberra he has met with Health Minister Peter Dutton, Social Services Minister Kevin Andrews and his Assistant Minister Mitch Fifield, who has responsibility for aged care and disabilities, as well as Chief Scientist Ian Chubb and officials from the Therapeutic Goods Administration to encourage Australia to be part of the G7 effort.   He will meet with researchers and deliver a lecture at the University of Melbourne tonight.

Dr Gillings is chairman of the World Dementia Council, which is working to reduce barriers to investment in research to speed up drug development, with a goal of finding a cure or disease-modifying therapy by 2025.

Dr Gillings said during the last century, about 30 years had been added to average life expectancy in the developed world through measures such as vaccination, new drugs and economic advancement.

"We stand to lose much of that gain to the ravages of dementia," he said.

"I think this would be a tragedy for medical research, and everything we and our colleagues have devoted our careers to."

Globally, around 44 million people are living with dementia, and this number is expected to rise to 135 million by 2050. The worldwide cost of dementia is estimated at $700 billion a year, or about 1 per cent of global economic output.

About 330,000 Australians are living with dementia and this is expected to grow to almost one million by 2050. Three in 10  Australians over the age of 85, and almost one in 10 over 65 have dementia. A person is diagnosed with dementia in Australia every six minutes.

Dr Gillings said the economic impact of dementia was "increasing relentlessly" and without improvements in prevention and treatment, governments could expect the cost of dementia – which is already more than $5 billion annually in Australia - to grow by 5 per cent a year.

But he said if the onset of dementia could be delayed by five years, the growth in costs could be contained to 2 per cent a year.

"That's substantial, because it moves us from something that's not affordable, to something that is affordable," he said.

Dr Gillings said despite being a "life shattering" disease, dementia attracted only one fifth of the research investment of cancer, because developing drugs for dementia was high risk and low reward.

He is encouraging governments to consider streamlining drug approval processes and introducing incentives such as tax credits to make it more attractive for pharmaceutical companies to invest in dementia research.

He praised the Abbott government's $200 million commitment to dementia research, which he said placed Australia in "the senior club of committed nations."