Ita Buttrose says Australia's aged care system is split between haves and have-nots and pensioners are "pretty well stuffed".

If you're a pensioner with dementia in Australia, you're pretty well stuffed.

"There's no other way to put it," says media personality and Alzheimer's Australia ambassador Ita Buttrose.

Ms Buttrose warns Australia's aged care system is being split between the haves and the have-nots.

There are no quality standards in the aged care sector and the system ignores the fact it's caring for real people, with the right to a life, she says.

"They're just in there - they're cared for, they're washed, they're watered, they're put out there, they gaze out the window, they see nothing much," she told the National Press Club in Canberra on Wednesday, World Alzheimer's Day.

"That's not good enough."

Ms Buttrose said funding cuts showed the government didn't understand the realities of aged care or how to support people with dementia.

She issued a stern warning to the nation's politicians.

"Politicians get older too and they also get lonely - we'd like to remind them of that."

More than 350,000 Australians are living with dementia, at an estimated cost to the health and aged care system of $5 billion each year.

It can take up to three years on average to get a diagnosis.

There are 1800 new cases diagnosed each week and the number of cases is set to triple in the next 30 years.

By the 2060s, the cost will be $83 billion unless more is invested in medical research to slow down progression of the disease, or cure it, Ms Buttrose said.

Dementia sufferers are some of the loneliest people in Australia, excluded from their communities, she said.

While Australia had made huge progress in supporting people with physical disabilities, dementia was still considered a terminal medical condition where nothing could be done.

"When they're given the appropriate support, they can, like the rest of us, lead meaningful lives."