Removing sugar is one of the most obvious ways to extend life expectancy. Credit:Tribune No one is yet signing off on an upper limit. Some people are talking about 125 years; others 600 years, which is the age by which, even if we could medically live forever, we would be as good as certain to have a life-ending accident. Getting even a handful of those extra years would require herculean efforts of the kinds at which we once excelled but now find daunting. Australia's first life table, published in The Sydney Morning Herald a century and a half ago, gave a newborn colonist just 45.6 years. One published today would give that newborn boy 80.4 years and a newborn girl 84.6. The figures are midpoints, derived from adding up the death rates at each year of life. Some newborns will live longer. In Melbourne's inner east and Sydney's north shore the typical newborn girl can expect 87 years. Indigenous Australians can expect much less, about 70 for a boy and 75 for a girl.

Australia's first life table, published in The Sydney Morning Herald, November 1867. Credit:Trove Higher education is associated with an extra four years, according to Melbourne University's Philip Clarke, although it may not be education itself that buys the years, but something that goes with it. Higher income buys an extra five to six years. Perhaps because of that it matters which electorate you are in. People in Labor and National Party electorates get fewer years than those in Liberal electorates. The early gains were relatively easy. In the 1860s an extraordinary 20 per cent of boys didn't make it to the age of five. Twenty per cent of girls didn't make it to 10. By ensuring that children survived the first few years, we boosted expected lifespans to 67 for boys and 72 for girls. Then came the cancer years. For two decades from the 1950s right through to the early '70s, life expectancies scarcely grew. Demographer Peter McDonald told the conference that Bureau of Statistics projections at the time factored in no further growth. Sixty-seven for men and 72 for women was as good as it was going to get. During this time, tobacco accounted for an astonishing one in every three deaths of men aged 35 to 69. Motor vehicle deaths were appalling, too. By 1972 one in every 20 male deaths involved a car.

One third of Australians are clinically obese, another third are overweight. A public campaign against sugar of the kind we had against tobacco would lengthen lives. Then, from the early 1970s, we got serious. Victoria led the nation in anti-smoking campaigns and in drink-driving and seatbelt laws. Deaths from smoking-related diseases plummeted, along with alcohol-related road deaths. Today transport accidents account for just 1.5 per cent of all deaths for men and fewer for women. A decade later we did it with AIDS. Remember the Grim Reaper campaigns and appeals to everyone at risk to get tested? Our rate got nowhere near as high as those in other countries, then slid towards zero. Here's our problem: most of the gains against young and middle-aged deaths have been taken. McDonald says even if we made cars even safer and medicines even better and eliminated all deaths below the age of 75, we would only add 3.6 years to the expected lifespan of a man and 2.2 years to the expected lifespan of a woman. We couldn't promise 90 years, let alone 100.

To get there we are going to have to cut deaths beyond 75. Fortunately, we know what to do. Statins are enormously effective. One pill containing statins, low-dose aspirin and blood pressure drugs has been found to cut the risk of heart attacks and strokes by 65 per cent. Sugar has led to an explosion in obesity. One-third of Australians are clinically obese, another third are overweight. A public campaign against sugar of the kind we had against tobacco would lengthen lives. But many Australians don't take the pills they are prescribed. Many more don't go to the doctor. Many, many more continue to over-consume sugar. At the conference half-serious suggestions included adding statins to the water supply in the same way as we add fluoride and withholding pensions from older Australians who don't fill prescriptions in the same way as we withhold family benefits from the parents of children who aren't immunised.

Loading If we really wanted to extend lives we would tax sugar and campaign against it like we did with tobacco. We would ban it in certain products and target its eventual elimination. And we would properly tax alcohol and ban its advertising. But we are not like we were in the 1970s. We've become less accepting of the nanny state, happier with the years we've got. Some of us still smoke. We've become happy not to live too far beyond 90.