10 celebrities who lived to 100 — and how they did it

• These 10 celebrities made it to 100 years old and have tips on how they did it. • Staying mentally and physically active can contribute to making it to triple digits. • George Burns took brisk walks and avoided stress; Jimmy Carter credited marrying "the best spouse."

You might expect all Hollywood stars to have outlandish health and wellness routines, but these 10 celebrity centenarians kept it surprisingly simple.

Living to 100 is rare, but those who do tend to have some things in common. Scientists who study aging say that genes play a role in how long a person will live, but lifestyle factors, including diet, exercise, stress, and social connections, play a larger one.

From Jimmy Carter to the Queen Mother, here's what famous people who lived to 100 credit their longevity to.