But the drugs cannot reverse brain damage that has already occurred, and they carry risks of their own because they also strip useful metals from the body, such as iron and zinc.

With a capacity of 400,000 tonnes and measuring 362m in length and 65m in width, this goliath can carry twice as much iron ore as most vessels now plying the route between Brazil and China.

Put simply, the blood becomes more watery and can't carry as much oxygen - iron deficiency anaemia.