Sports writer David Epstein tracks down some surprising health claims circulating in the football world.

David Epstein is author of the recent New York Times bestseller The Sports Gene, an exploration of the genetic basis of athleticism. He is currently an investigative reporter at the non-profit ProPublica. Up until September, he was a senior writer at Sports Illustrated. He has been a crime reporter at the New York Daily News, and an education reporter at Inside Higher Ed. In his past life, David was a geology grad student. He has lived in the Sonoran Desert, on a ship in the Pacific Ocean, in the Arctic in Alaska, and -- like every other writer -- in Brooklyn.