Atomic Tune-Up: How the Body Rejuvenates Itself For most people, a makeover means losing weight and getting new clothes, hairstyle and makeup. But the body does its own extreme makeover each year, regularly replacing 98 percent of its atoms. The atomic makeover prompts a more philosophical question: Are people still themselves if their atoms are always new?

Atomic Tune-Up: How the Body Rejuvenates Itself

Atomic Tune-Up: How the Body Rejuvenates Itself

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On Star Trek, Dr. Leonard McCoy, played by actor DeForest Kelley, never wanted to be beamed anywhere because he worried it would scatter his atoms across the universe. Hulton Archive/Getty Images hide caption

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Hulton Archive/Getty Images

On Star Trek, Dr. Leonard McCoy, played by actor DeForest Kelley, never wanted to be beamed anywhere because he worried it would scatter his atoms across the universe.

Hulton Archive/Getty Images

For most people, a makeover means losing weight and getting new clothes, hair and makeup.

But what they may not know is that the body does its own extreme makeover regularly. In fact, 98 percent of the atoms in the body are replaced yearly.

Researchers in the 1950s made the discovery by feeding their subjects radioactive atoms. Using radiation detectors, the researchers watched the atoms move all over the body. They found that the new atoms replaced old ones and ended up in all tissues of the human body.

But these atomic makeovers prompt a more philosophical question: Are people really themselves if their atoms are always new, or are they new people each year? David Kestenbaum tackled that philosophical question — and discussed atomic makeovers — with the experts.