Is it Healthier to Live in Summit County?

Is it somehow healthier to live in Summit County? That's what a new study from Harvard University seems to say.

Summit and six other counties located along the Continental Divide in Colorado lead the nation in longest average life expectancy, 81.3 years.

The only thing these places have in common, other than people long in the tooth, is thin air. The lowest point in any of them is in Eagle County, at the edge of Glenwood Canyon, where the elevation is about 6,000. Some principal towns in the group range from 9,000 to 10,000 feet in elevation.

The Harvard researchers don't know why mountain counties lead the nation in longevity.

There are two theories. One can be called the theory of self-selection. When people get sick, particularly with chronic lung and air diseases, they tend to leave the High Country for places with lower elevation like Grand Junction, Denver, Tucson and Phoenix, where medical facilities are generally better and where the air has more oxygen. This is mostly anecdotal, although one study conducted in the early 1980s documented the migrations in Colorado. On the other hand, migrants who are healthier may be drawn to mountain counties. The aging population is increasing in ski towns. The above-60 age cohort, while still relatively small, was the fastest-growing population segment in the 1990s. One of the researchers, Majid Ezzati, said that the research team had studied broadly demographic migrations, but not from individual counties. As such, those migrations in and out of mountain counties could explain their high rankings.

A second theory is advanced by Dr. Benjamin Honigman, director of the Colorado Center for Study of Altitude Medicine and Physiology. That theory holds that people who have lived at higher elevations for a long time develop a protective effect that yields stronger lungs and hearts. That has been proven in populations who have lived hundreds or thousands of years in high elevations. Tibetians, for example, have lived at locations of 12,000 feet and even higher. But that theory lacks supporting evidence, says Honigman. "There isn't much known about longevity and altitude," he says.

Honigman hopes to find money to study the connection between thin air and health. For example, Colorado also has a lower rate of heart attacks and stroke than most places, but it's not known why. It's a classic chicken-and-egg question: Do people in Colorado have behaviors that make them healthier, or is it because living in Colorado makes them healthier?