Researchers from the American Cancer Society made a startling announcement Tuesday: After decades of decline, the average annual death rate in the U.S. has leveled off.
Consequently, our expected life span has plateaued – staying at 77 years – for the first time since researchers started tracking it in the 1960s.
What’s going on here?
The findings were presented in a report published in the Journal of the American Medical Association. For the report, scientists used federal mortality data to track life spans from 1969 to 2013 and discovered the decline in death rates has leveled off from 2010 to 2013. The rate specifically dropped by just 0.4 percent year over year, during that time frame, which is not considered statistically significant.
However, this news is surprising in a time of frequent medical advances and improved access to healthcare — and it surprised researchers as well.
“I didn’t expect the slow-down,” lead study author Ahmedin Jemal, PhD, vice president of surveillance and health services research at the American Cancer Society, tells Yahoo Health.
Jemal says there may be a few reasons for the leveling off. The first, and potentially most significant, is the obesity epidemic. “Obesity has dramatically increased over the last three to four decades,” he says.
Research has shown we’re losing the war on obesity. A study published earlier this year in journal JAMA Internal Medicine found that the majority of Americans are now considered overweight or obese.
Obesity and excess body fat is linked to an increased risk of developing potentially deadly diseases such as Type 2 diabetes, heart disease, and several types of cancer, says Jemal. And the risk typically increases the more a person is overweight.
During the four decade time frame of the study, death rates for some diseases and illnesses such as heart disease, cancer, diabetes, and stroke fell significantly. However, it tellingly leveled off recently for those related to obesity like diabetes, stroke, and heart disease.
Smoking may also be a factor, Jemal says. Despite widespread knowledge that smoking is linked to a host of diseases such as lung cancer, emphysema, and heart disease, about 18 percent of the population smokes, the American Cancer Society reports. That number is down from 42 percent in 1965, but smoking is still prevalent among high school students — one in four male high school students and nearly one in five female high school students uses some form of tobacco.
High rates of hypertension and cholesterol could also be a reason for the plateau, Jemal says.
But he also points out that our life expectancy can only be pushed so far — and we’ve come a long way. “In 1900, the life expectancy was in the low 40s,” Jemal says. “In 1950, it was in the mid-60s. It’s now about 77 years.”
However, he says, this doesn’t mean it won’t change in the future. He specifically cites the higher life expectancy in Canada (80 for men, 84 for women), Germany (80 years), and France (82 years) as a sign that there’s room for improvement.
Jemal says it’s difficult to predict what will happen to our life expectancy in the future, but he’s hopeful it will get better over time. “If we can improve smoking, obesity, physical activity, and diet, we can decrease the mortality rate,” he says. “We cannot avoid diseases, but we can push them so that people live longer.”