The Tsimané people of Bolivia have almost no dementia. Scientists say modern life is our problem. (GOOD)

GOOD featured research by Andrei Irimia on how indigenous groups in the Bolivian Amazon show less dementia and slower brain aging than industrialized populations. “The lives of our pre-industrial ancestors were punctuated by limited food availability,” Irimia said. “Humans historically spent a lot of time exercising out of necessity to find food, and their brain aging profiles reflected this lifestyle.”