Has the 120-year-old mystery of Sir Ernest Shackleton's deteriorating health finally been solved? Antarctic explorer had to return home after voyaging close to the South Pole in 1901 due to a bout of 'beriberi' and NOT scurvy, new study claims Antarctic explorer Sir Ernest Shackleton came close to the South Pole in 1901 The explorer had to return home after struggling with deteriorating health Previous theories suggested was linked to scurvy or a congenital heart defect A team explored the health condition of others on the same 1901 expedition US researchers say their findings suggest that the British explorer suffered from beriberi, a serious and potentially life-threatening condition