An international team of scientists announced Monday that people across the globe are living longer, healthier lives compared to a generation ago, an achievement researchers largely attributed to advances in medical science.
The new study finds that the last few generations of humans are experiencing a boost in life expectancy that is unprecedented in the history of primates, i.e. the family of mammals including people, apes and monkeys.
Researchers from the United States, Germany, Denmark, Kenya and Canada looked at the birth and death records of more than 1 million people born around the world between the 1700s to the present. The data included records for those living in industrial societies as well as modern day hunter-gather groups. The latter were included as a sort of control group to compare how long people lived without easy access to many contemporary amenities such as supermarkets or vaccines.
The results show that a baby born in Sweden today, for example, can expect to live more than twice as long as one born in the 19th century. Then, Swedish life expectancy hovered around 35 years; the average Swede now lives beyond 80 years of age.
Interestingly, those living in industrial societies live 40 - 50 years longer than those living in traditional hunter-gatherer groups, such as the Aché people of Paraguay. These hunter-gatherers outlive wild primates by 10-20 years.
The research was published online Monday in the journal Proceedings of the National Academy of Sciences by researchers from Duke University, Princeton University, the Max Planck Institute in Germany and elsewhere.
"We've made a bigger journey in lengthening our lifespan over the last few hundred years than we did over millions of years of evolutionary history," co-author Susan Alberts of Duke University said in a statement.
One puzzling discovery in the data is that women still outlive men by two or three years, a statistic that has barely changed for centuries. The stubborn gender gap appears to exist for nearly all other primates as well.