[dcolkitt]

> bloodletting was a popular medical procedure up to 19th century

You know a funny story about this, is that bloodletting (phlebotomy) is the standard medical treatment for iron overload and hemochromatosis. A hereditary condition that affects as many as 1% of Northern Europeans.

Even for those without hereditary hemochromatosis, there's evidence of pernicious health impact from iron levels even on the high-end of normal.[1] Regular blood donors have much lower incidence rates of disease as varied from Alzheimers to colon cancer. This is especially true for those who are carriers of the hemochromatosis mutation, which is as much as 10% of Northern Europeans.

[1] http://nautil.us/issue/67/reboot/iron-is-the-new-cholesterol