Three generations of women

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What Keeps You Young?
More than a decade ago, an internist named Michael Roizen, MD, had a light-bulb idea: He was sure there was a way to calculate a number that represented not your calendar age, but how fast your body actually ages—your body's "RealAge." 

He was right—it just wasn't easy. At that time, researchers were just beginning to learn how individuals have a certain amount of power over the ways their genes affect their lives. Five years and tens of thousands of medical studies later, Dr. Roizen and a team that included Keith Roach, MD (now chief medical officer of RealAge) had not only pinpointed which key factors make you physically older or younger—from vitamin E and your parents' genes to whether you floss—but had also figured out how much older or younger each one makes you. When the RealAge test was launched, Oprah said, "You've got to take it."

Fast forward to today. The RealAge Test has just received its first major scientific update. If you're one of the 27 million who've taken it, odds are your RealAge has changed. Are you younger (or older) than you think?