There are more people than ever aged 100 years of age and older in Australia, and a new study has found that as a group they need less home care than seniors who are approaching their 100th birthdays.

"They seem to go into old age much healthier," said Colette Browning, director of the Royal District Nursing Service (RDNS) Institute.

"Even though they do have a number of chronic illnesses, they seem to be able to manage better."

The RDNS Institute is part of RSL Care and RDNS, which supports more than 110,000 seniors in their homes and in residential aged care.

The institute analysed the health records of 123 centenarians, and more than 1,000 "near centenarians" aged 95 to 99.

It found once seniors reached 100 years of age, their required home visits actually declined to an average of 58 home visits per client over two years.

Near centenarians required an average of 72 home visits over two years.

The question is — why?

Ms Browning has some theories. Good genetics are important, and so are good habits regarding food and drink.

But Ms Browning believes life experience also plays a role.

"We need to think about who these people are in terms of their life course," she said.

"They were teenagers in the Great Depression. They were middle-aged during the '60s... they seem to have a way of coping with stress, an attitude to life that's maybe a bit more positive."

If anyone embodies that spirit, it is 100-year-old Bert Bush, who lives on Victoria's Mornington Peninsula.

"I want to live life, now that I'm 100 years of age," he said.

"I know I can't live the age of a 20-year-old, but I still want to live life."

100-year-old Bert Bush is the primary carer for his 88-year-old partner Joyce. ( ABC News: Norman Hermant )

Mr Bush recently cut down on his sporting activities. He no longer bowls at his local club, but he stays active.

He is the primary carer for his 88-year-old wife, Joyce. The two live on their own, with regular home care visits to help with things around the house.

They even have a special double seat mobility scooter so they can still regularly head down to the local shops for coffee.

"If you think because of your age, you're going to just sit down and grow old in a chair, well that's not for me," he said.

There are more than centenarians than ever before in Australia — 4,400. And that number is set to grow.

The proportion of the population aged over 85 nearly doubled in the past two decades.

A centenarian's secret to long life

Since turning 100, Denise Johnston has given herself a pass on exercise. ( ABC News: Norman Hermant )

If there is a secret to a long life, centenarian Denise Johnston agrees it's not complicated.

"I sort of don't worry about things too much," she said.

Ms Johnston just turned 100. She has had some health issues, and an RDNS nurse comes twice a week to change compression stockings on her legs.

But living in part of a house next her son and daughter-in-law, with books to read and "telly" to watch in her favourite chair, she's happy.

"I probably should do more exercise," she said.

When it's suggested that at age 100, she can give her herself a pass on exercise, she agreed.

"I think I gave myself that pass a long time ago," she said, laughing.