When Professor Creswell Eastman visited a remote, mountainous region of Tibet in the 1980s, he was shocked by what he found. While researching the extent of iodine deficiency disorders, he came across entire villages filled with people with low IQs, large goitres (enlarged thyroid glands) and other deformities, many of whom were deaf and mute.

“It was like some kind of medieval scene,” he says. “It was hard to believe that we were living on the same planet.”

When he returned home to Australia, he couldn’t stop thinking about what he saw, and felt compelled to do something to help. In the decades since, Eastman has led many projects to abolish iodine deficiency – the most common preventable cause of brain damage throughout the developing world. His work with populations in remote areas of China led him to be dubbed ‘the man who saved a million brains’, but in reality he and his team have saved countless more, including in Malaysia, Laos, Thailand, Vietnam and Indonesia.