New analysis of a group of all-women extreme divers called Haenyeo—native to Jeju Isand, off the coast of South Korea—has uncovered genetic differences that could help them survive the intense physiological stresses of free-diving. These women spend hours in the water every day harvesting seaweed, abalone, and other food items from the seafloor—up to 60 feet below the surface, without equipment. In a study that measured physiological variables and sequenced participants’ DNA, researchers found two genetic changes that could give the Haenyeo advantages underwater: For Haenyeo with a lifetime of diving experience, heart rate drops by up to twice that of an average untrained person from the area, which may also be associated higher tolerance to cold-based pain. And because Jeju Island has one of the lowest rates of stroke mortality in Korea (and a significantly lower rate than in the U.S.) researchers posit that the Haenyeo’s genetic variations could help protect against stroke—insights that could ultimately lead to better treatments for blood pressure disorders.
