Survival of the sickest chapter 1 summary

hemachromatosis is a hereditary disease, the most common genetic disease for people of European descent, in which the body can't register that it has enough iron. So it continuously absorbs as much of it as possible, and this can have very serious side effects (including death). Iron is very important for bacteria, cancer, and other things to grow which is why too much iron is so dangerous. during the black plague in Europe, people with more iron in their system were more likely to die because bacteria feeds on iron. Women, children, and the elderly were significantly less targeted than men. But people with hemachromatosis also happen to have white immune system blood cells with considerably less iron than the normal person, and this counteracted the precise way that the bubonic plague killed its victims - through their own immune system. Because of this lack of iron, people were actually able to fight off the disease, and their lives were spared.