In a perfect world, we'd all live to see 100. We're not quite there yet, but a new study suggests that by 2030, life expectancy is set to increase globally — and that South Koreans may live the longest, up to age 90 on average.

Scientists from Imperial College London in collaboration with the World Health Organization set out to study longevity, which reflects "one measure of the overall health of a population," Imperial researcher James Bennett told Seeker.

The team developed a Bayesian model averaging (BMA) system, a method that's commonly used to crunch weather data and make predictions, to analyze age data for 35 industrialized countries. They used age-specific death rates, which reflects health during the entire life course, and then calculated life expectancy for people in various countries at birth, again at age 65, and then looked at the probability of dying before age 70.

The countries in the study ranged from high-income nations, such as the United States, Canada, the U.K., Germany and Australia, to emerging economies like Poland, Mexico and the Czech Republic — and all countries had data dating back to 1985 and a population of 1 million or more during the entire period.

Based on the team's calculations, a baby girl born in South Korea in 2030 will have an average life expectancy of 90.8 years. A baby boy born in the same place and time would be expected to live to age 84.1 years.

In the past, an average life expectancy over age 90 was once considered impossible, Majid Ezzati, a lead researcher from the School of Public Health at Imperial, said in a press release. "Many people used to believe that 90 years is the upper limit for life expectancy, but this research suggests we will break the 90-year-barrier," he said. "I don't believe we're anywhere near the upper limit of life expectancy — if there even is one."

"South Koreans projected gains may be the result of continued improvements in economic status, which has improved nutrition for children, access to healthcare and medical technology across the whole population," Bennett told Seeker. "This has resulted in fewer deaths from infections and better prevention and treatment for chronic diseases, in a way that is more equitable than some Western countries."

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Among high-income countries, the U.S., however, ranked lowest, at a life expectancy of 83.3 years for women and 79.5 years for men in 2030. In comparison, French women are expected to live until age 88.6 and Swiss and Australian men until age 84.

"U.S. life expectancy is already lower than most other high-income countries, and is expected to fall further behind in 2030, potentially as a result of its large inequalities, absence of universal health insurance and of the country having the highest homicide rate, body mass index and death rates for children and mothers of all high-income countries," Bennett said.

The research also suggest that the life expectancy gap between men and women is closing. "Men traditionally had unhealthier lifestyles, and so shorter life expectancies," Ezzati said, explaining that they smoked and drank more and had more road traffic accidents and homicides. "As lifestyles become more similar between men and women, so does their longevity."

These findings could help to better set expectations for governments planning for health and social services and for pensions around the world.

In the future, Imperial researchers plan to tackle two more areas: include cause specific mortality to gain new insight into some of the major diseases impacting humans and extend average life expectancy analysis for every country in the world. Bennett said this will be "a very challenging area, as data from many countries are not as clean or reliable as those in the study."

The study shows potential for many people living longer around the world, though the U.S.'s ranking is a wake-up call that the country might have some catching up to do.

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