WEDNESDAY, Dec. 26 (HealthDay News) -- U.S. service members who died in Iraq and Afghanistan had been healthier than troops in previous wars, military researchers report.

Although almost 9 percent of those autopsied had some degree of atherosclerosis (or "hardening") of their coronary arteries, which can lead to heart disease, this was far lower than seen in soldiers who died in Vietnam or Korea, researchers say.

Similar studies had shown that 77 percent of soldiers in the Korean War and 45 percent in the Vietnam War had atherosclerosis, Webber's group noted.

But the numbers found in the survey of today's troops "are probably lower than those seen in the general U.S. population," added lead researcher Dr. Bryant Webber, from the Uniformed Services University of the Health Sciences in Bethesda, Md.

Webber believes the military's medical care is in part responsible for healthier troops. "Some of the things the military is doing -- like addressing high blood pressure, high cholesterol -- we are doing well," he said.

In addition, they have concentrated on weight management, reducing smoking and improving fitness. "We are doing some things right, compared to previous years," Webber said.

Another expert agreed.

"We had a wake-up call 60 years ago when data from young soldiers killed in the Korean War showed a very high prevalence of coronary disease," said Dr. Daniel Levy, director of the Center for Population Studies at the U.S. National Heart, Lung, and Blood Institute in Bethesda, Md. He was also the author of an accompanying journal editorial.

That seems to have turned around based on this current study, he said. "There seems to be some good news that a lurking, dangerous condition appears to be far lower in prevalence today than it was in prior decades," Levy said. He attributes these gains to more attention to a healthy lifestyle and to risk factors such as blood pressure, cholesterol and smoking cessation.

Yet despite these improvements, there are young people fit enough to go into combat who are still at risk for heart disease, Webber added.

The report was published in the Dec. 26 issue of the Journal of the American Medical Association.

For the study, Webber's team looked at almost 4,000 autopsy reports of U.S. service members who died of combat or unintentional injuries between 2001 and 2011 in Iraq or Afghanistan.

Researchers found that, overall, a little more than 12 percent had some hardening of the arteries -- with 8.5 percent having any atherosclerosis, 2.3 percent with severe atherosclerosis, 4.7 percent with moderate atherosclerosis and 1.5 percent with minimal atherosclerosis.

One of the factors contributing to artery hardening was age -- those 40 and over were seven times more likely to have the condition than those aged 24 and younger, Webber said. Almost 46 percent of the older soldiers had some atherosclerosis, compared with only about 7 percent of the younger group.

Other factors included weight, with those who were overweight or obese more likely to have some atherosclerosis; and education, with those with less education more likely to have the condition.

Obesity levels have grown worse in the past 60 years, Levy said. "One worrisome note is the proportion of young people who are overweight and obese has gone up, which carry with it considerable risks," he said.

"We have already seen increases in diabetes," Levy noted. "So while most of the risk factors have trended in the right direction, obesity and diabetes are going in the wrong direction, and that's a source of concern of what will happen in the future to our population," he said.

In addition, those with atherosclerosis in the study were more likely to have been diagnosed with risk factors for heart disease -- such as high cholesterol, high blood pressure or obesity -- than those without the condition, the researchers noted.

Another expert agreed that the heart health of soldiers has improved over time.

"There has been a substantial decline in the rates of fatal and nonfatal cardiovascular events in the U.S. since peaking in the late 1960s," said Dr. Gregg Fonarow, a spokesman for the American Heart Association and professor of cardiology at the University of California, Los Angeles.

This decline has been attributed to improved treatment of cardiovascular disease as well as improved prevention efforts, particularly decreases in smoking, reductions in cholesterol levels and better management of blood pressure, he explained.

"Autopsy studies of U.S. soldiers killed during the Korean War demonstrated that coronary atherosclerosis was anatomically present in three out of four young adults killed in combat," Fonarow said.

"Whether these rates of coronary artery disease in young adults have decreased or not in more recent decades has not been well studied," he added.

This new study shows a very notable decline in the prevalence of coronary artery disease, Fonarow said.

However, he added, "Despite this remarkable progress, cardiovascular disease remains the leading cause of death and there are further opportunities to improve prevention efforts and achieve more ideal cardiovascular health."

More information

To learn more about heart disease, visit the American Heart Association.