Professor Alexandre Kalache grew up in the bustling Brazilian city of Rio de Janeiro, at a time when the average life expectancy for the nation’s citizens was just 43.

More than five decades on that number has almost doubled to 75, a trend that is reflected in developing nations around the world.

However, the rapid pace of ageing, while astonishing in the course of just one generation, poses the greatest challenge to modern society, Professor Kalache says.

An expert in the fields of ageing and gerontology, Professor Kalache says his childhood in Brazil, spent in a busy household of multiple generations, informed his attitude towards older people.

“My grandmother had 13 brothers and sisters, and my grandfather had 17 siblings, so I had very close contact with older relatives,” says Professor Kalache, the president of the International Longevity Centre in Brazil, and HelpAge International in London.

Professor Kalache believes the move away from extended families living under the same roof is leading to a lack of empathy from younger generations towards their elders.

“Each of my grandparents came from Portugal, Italy, Greece, and Lebanon, and we didn’t have a television, so I listened to lots of fascinating stories growing up.”

Professor Kalache was recently in Wollongong as a guest of Global Challenges. A member of the Living Well, Longer Advisory Board, he also took part in ‘A Conversation With’, a series in which a renowned academic takes part in an informal chat about their career.

Professor Kalache, a trained doctor, has devoted his work to understanding ageing, and what it will mean for society as we move further into the 21st century.

As Director of the World Health Organisation, a position he held from 1994 to 2008, he pioneered the concept of active ageing and launched the Global Movement on Age Friendly Cities.

“I’ve never looked back,” he says of his decades spent researching geriatrics. “When I moved to the United Kingdom in 1975, no one spoke about ageing. I saw an opportunity. No one could have predicted the speed of ageing that has occurred.”

The world, he says, is struggling to both understand and support its ageing population. And this older generation is not going in to their twilight years quietly. Rather, Baby Boomers, who have changed societal definitions of each stage of life they pass, are again disrupting what it means to age.

“Baby Boomers have a very different idea of retirement and ageing,” Professor Kalache says. “Just as they were the original disrupters in the 1960s and 1970s, they are disrupting the wisdom of what ageing means.”

He explains that Baby Boomers have created a new stage in life – a concept he terms “gerontolescence”, a older version of that definitive stage of transformation, adolescence – in which they are embracing ageing and viewing life post-retirement as exciting, rather than exhausting.

Professor Kalache argues for greater understanding of and strategies for older generations, to ensure they receive the support they deserve and are able to continue contributing to society. Otherwise, he says the experience and wisdom of our older members of society will be lost.

Initiatives such as Global Challenges’ Living Well, Longer enable society to view ageing in a more positive light and recognise the importance of embracing every life stage, even if it brings greying hair and a few wrinkles.

Professor Kalache’s passion for the subject, which sees him work with organisations throughout the world on the importance of active ageing and creating age-friendly cities, is infectious and it is clear that his own retirement is not in sight.

“When I was born, life was a 100 metre sprint. Now it is a marathon,” says Professor Kalache, who entertained the ‘A Conversation With’ crowd with his anecdotes of life in Brazil, where he still lives.