A recent study tried to explain the phenomenon in which immigrants seem to have longer life expectancies than people native to the country:

It’s a epidemiological mystery. In rich countries immigrants often seem to live longer than native-born residents, a fact that appears to fly in the face of public health assumptions. After all, richer and better-educated people usually tend to live longer, and in the U.S., at least, immigrants tend to be poorer, less well-educated and have poorer access to health care. Despite that, native-born residents are still dying earlier than their immigrant counterparts — something called the “healthy immigrant effect.”

The study was based on vital statistics data and data from the 2000 US Census.  It found that:

…smoking explains more than half of the difference in life expectancy at 50 years between foreign-born US residents and native-born Americans, and close to three-quarters of the difference in life expectancy between US Hispanics and non-Hispanic Whites.

So, while immigrants may have some issues with adapting to a new culture, sometimes their “old world” values may benefit them in their new country.  The conclusions from this research were particularly interesting to me, since smoking is especially taboo among Sikhs.

The study’s abstract can be viewed here.