Which are the youngest & oldest cities in America? Find out which places topped RealAge 2012 list for staying young and which tanked.

What a surprise to discover which cities rank healthier than Denver. You’ll also be surprised to know how Denver ranked. See the full listing here.

This year, RealAge reviewed two dozen factors that influence a person’s RealAge to reveal the best places to stay young. Lifestyle choices have a big impact on a city’s age, says RealAge cofounder Michael F. Roizen, M.D. “Cities with the lowest stress are basically the youngest. Stress, smoking, diet, exercise — all four of those seem to go together.” When residents take good care of themselves, they tend to have lower rates for high cholesterol, hypertension, and diabetes. And that translates to a younger RealAge.

Denver, CO
Residents of the Mile High City and its neighbor Boulder rank best in the country for optimism. They’re also third best for exercise, thanks to more than 850 miles of off-road trails for cycling, running, and hiking. All that activity helps Denver-Boulder rank as the best place to dodge cholesterol and diabetes, and second-best place for healthy blood pressure

Where does your city rank? Do you live in a city where you stay younger? Or do you live is a city where you are aging too fast? I was surprised with some of the rankings. RealAge