Life expectancy. From 45 to 82 years, we've come a long way

Life expectancy. From 45 to 82 years, we've come a long way

Peter Martin | Fairfax Media | November 6 2017

One hundred and fifty years ago on Tuesday [November 6] The Sydney Morning Herald broke news that these days would be considered shocking.

The first 'life table' prepared for the British colony put the expected lifespan of a newborn non-Aboriginal Australian at just 45.6 years.

The Bureau of Statistics now gives newborns a lifespan of 82.5 years; 80.4 for boys, and 84.6 for girls.

And that's almost certain to be an underestimate. Improvements in medical technologies throughout 80 years of life are likely to add an extra four years to those totals.

On November 7, 1867, the life table was good news. We were better off than England where newborns got only 40.9 years, and better off than Belgium where they got 32.2.

And things were even better than the raw figure of 45.6 years suggested. An extraordinary 10.6 per cent of newborns (10.6 per cent of boys, 9.8 per cent of girls) died before they reached the age of one. If you survived to the age of one, you were likely to make it to 51.

From today's vantage point it looks as if life expectancy has always increased, but it hasn't, for decades at a time. The 1960s were what Melbourne University demographer Alan Lopez refers to as the "tobacco years". Life expectancy increased not at all.

For older Australians life expectancy scarcely increased for 50 years, between 1920 and 1970. It was only after 1972 when the tobacco use was brought under control (it didn't finally peak until 1978 - 1980) and progress was made against heart attacks that it began to grow again.

In recent years, newborns have been gaining an extra year of life every two and a half years. Australian National University demographer Liz Allen can't see an upper limit, although she concedes it will be more difficult. Controlling tobacco, preventing heart disease and making driving safer were easier to do than it would be to extend the lifespan of the parts of our bodies with built in obsolescence. Our bodies weren't designed to last too many years beyond childbirth, she says.

Alan Lopez says we've already harvested most of the low-hanging fruit. "The gains in lung cancer, chronic heart disease and the tobacco causes will continue, but at a much slower rate," he says. The gains from road accidents will depend on whether we adopt strict road rules of the kind Sweden has where there is a zero tolerance for alcohol.

At a public lecture to be presented at Melbourne University next week, he will suggest that life expectancy will continue to climb for the next 25 years, but at half the rate of the previous 25 years.

The biggest obstacle will be obesity, which has helped turn back the life expectancy of white men in the United States.

"Roughly one-third of Australians are obese, another third are overweight," he says. "Thirty or so years ago it might have been only 10 per cent. We don't yet know what the full effects of that will be, we do know that we are not having success in bringing it down."

Liz Allen says it's important to distinguish between the maximum possible lifespan (which at the moment is 122 years) and life expectancy. Life expectancy depends on conditions; on things such as sanitation, education and income. That's why it's nine to 11 years worse for Indigenous Australians. Who gets the extra years will be up to us.

By numbers:

Life expectancy at birth

1867: 45.6 years

Today: 82.5 years

Extra years expected at age 65

1867: 9

Today: 20

Photo by Liane Metzler on Unsplash

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