By Dennis Thompson
However, that's not necessarily because U.S. residents have rotten lifestyle habits that ruin their heart health, the researchers added.
Instead, "people who immigrate, they seem to be healthier than those who decide to stay in their home country," said lead author Dr. Jing Fang, an epidemiologist with the U.S. Centers for Disease Control and Prevention.
They found that just over 8 percent of men and close to 5 percent of women born in the United States have heart disease, compared with 5.5 percent of men and just over 4 percent of women born elsewhere.
Native-born Americans also had a higher rate of stroke -- 2.7 percent for both men and women, versus 2.1 percent for foreign-born men and 1.9 percent for foreign-born women.
Heart disease was lowest among people born in Asia, Mexico, Central America or the Caribbean, researchers found. Stroke occurred least often in men from South America and Africa, and women from Europe.
Most surprisingly, researchers found that the length of time an immigrant has lived in the United States did not affect their risk for heart disease or stroke.
"Our first thought was that the longer people live in the U.S., they will have more problems than recent immigrants," Fang said.
It could be that immigrants who choose to make the move to America bring with them a lifestyle learned in their childhood that is better for their heart, said Dr. Eduardo Sanchez, the American Heart Association's chief medical officer for prevention.
"If indeed people are coming here with a different set of health habits, maybe those are part of what confers better health," Sanchez said.
At first glance, one might think that immigrants have better heart health because Americans struggle with obesity, poor diet and lack of exercise.
But Fang noted that countries in Europe, Asia and Africa typically have higher death rates from heart disease and stroke than the United States.
This led Fang and her colleagues to raise the possibility of a "healthy immigrant effect," in which people who decide to move to the United States are generally healthier than those who remain in their home country. This could be either because these folks are more motivated, or because the physical and legal barriers of coming to America require a certain amount of moxie.
Sanchez said an interesting follow-up study would be to look at the children of these immigrants to see if they pick up those healthy habits from their parents, or adapt to the less-healthy American lifestyle.
"Those children born into the culture of America may have a health status that looks more like that of people who have been born in America for many generations," Sanchez said.
The new study was published March 28 in the Journal of the American Heart Association.