More people around the globe are living long enough to get cancer

Around the world, people are getting healthier. Child mortality rates are falling, fewer people are dying of HIV/AIDS, and people live an average of 10 years longer than they did in 1980. But as life expectancy hits an all-time high, the growing burden of chronic disease is posing new obstacles to global health systems, according to a new report published in the Lancet.

Someone born today can expect to live for 71.8 years, up from 61.7 years just 35 years ago, based on the latest findings in the 2015 Global Burden of Disease study from the Institute for Health Metrics and Evaluation at the University of Washington.

Life expectancy improvements varied from region to region. Several countries in Africa saw their populations living more than 10 years longer, while people in war-stricken Syria will live 11 fewer years than older generations.

Driving the extended lifespans is an overall decline in deaths caused by infectious diseases like HIV/AIDS and malaria.

Since the 1980s, the HIV epidemic has had one of the most profound and sustaining impacts on global health. At its peak, HIV killed more than 1.7 million people worldwide in 2005. Now that number is down by more than 33 percent, with 1.2 million deaths a year. While a catastrophic event, like a natural disaster or a violent conflict, can temporarily impact death rates, the HIV/AIDS epidemic was unique.

"HIV is sort of one of those big shock events, big high-fatality events," said Dr. Nick Kassebaum, an associate professor at the University of Washington and one of the study's authors. The virus has endured for years and particularly devastated younger populations, predominantly in Africa. "Because it was so widespread in sub-Saharan Africa where there's a huge number of people," he said. "It had a big impact on life expectancy at the global level."

Another reason people are living longer is declining maternal and child death rates. Last year, 5.8 million children under age 5 died, about half the number of deaths in that age group in 1990. The number of women dying from childbirth dropped by a third during the same period, with a total of 275,000 such deaths around the globe in 2015.

As the world succeeds in tackling these issues, health systems face a new challenge: the burden of chronic diseases like cancer, heart disease, drug use, and diabetes.

Currently, 70 percent of deaths globally are linked to these so-called noncommunicable diseases, due to a growing population that's living longer. As more people spend more time living in poor health and the occurrence of chronic diseases increases, countries will have to adapt their medical systems to cope.

"This has far-reaching implications, not just for health-system financing and service delivery but also for economic growth and well-being," the authors wrote.