People now live longer and healthier thanks to advances in medicine and public health. Findings of a new study, however, have shown that despite improvements in longevity, gender gap still exists in life expectancy with women likely to live longer than men.
Humans And Primates Now Live Longer
In the new research, which was published in the journal Proceedings of the National Academy of Sciences on Nov. 21, Duke University biology professor Susan Alberts and colleagues looked at the data of more than 1 million individuals worldwide beginning the 18th century to the present.
The researchers also looked at the mortality patterns of monkeys and apes. They found that the last few generations enjoyed the greatest life expectancy increase, and this was observed not just in humans but also in all other primates.
Contributors To Improved Life Expectancy
Advances in medicine and public health are among the contributors in gains, as these help increase the likelihood of survival and reduce death toll from illnesses.
Over the past two centuries, life expectancy in Sweden increased from mid-30s to more than 80 years. In the United States, life expectancy of those who were born in 1900 was only 47 years. Now, Americans can expect to live until 79 years old.
Males Still Trail Behind Females
Males, however, still trail behind females when it comes to life expectancy, and the pattern is observed across members of the primate family tree, including humans.
"In spite of the astonishing progress humans have made in lengthening the lifespan, a male disadvantage in lifespan measures has remained substantial — a result that will resonate with enduring public interest in male-female differences in many facets of life," the researchers wrote in their study.
Reasons Behind Gender Gap In Life Expectancy
Several hypotheses have been proposed to explain the gender gap, one of which is genetics.
Male primates carry only one copy of the X chromosome while females have two copies, so males do not have a second X chromosome that can compensate for harmful gene variants in their X chromosome.
"The male disadvantage has deep evolutionary roots," Alberts said.
Higher level of risky behavior in men may also be responsible for the difference. Engaging in risky behaviors such as drinking and driving is known to increase odds of sustaining injuries.
The researchers said that identifying the culprit behind the gender gap in life expectancy and being able to come up with interventions may help men to catch up.