For my latest book I headed inside the body to look at blood, a marvellous substance that can kill us or save us; that is feared and revered, and always has been. But I also travelled widely — to India, Nepal, South Africa and the Canadian prairies — to understand the place of blood in our world. I explored why menstrual blood is still considered so taboo, girls are forced to live in unheated sheds when they have their periods; how modern trauma care is maybe using the wrong kind of blood; why leeches are still found in hospital pharmacies; and why thousands of people are still seeking justice after they were given contaminated blood products in the 1980s.
I learned dazzling facts about blood. Every three seconds, a person receives some from a stranger. Our veins and arteries, measured, are sixty thousand miles long, or twice the circumference of the earth. Every day, our trillion red blood cells travel about twelve thousand miles around our bodies. There are more than 300 known blood types, far more than A, B, O, and scientists still don't know why we have them.
I discovered wonderful characters such as Dame Janet Vaughan, a pioneering haematologist who helped set up the modern blood supply in England, but who was dismissed by her boss as "a very naughty little girl." I met Arunchalam Muruganantham, a poorly educated machine worker who asked his wife one day what she was hiding behind her back. Because it was "nasty cloths," (menstrual rags), Muruga decided to change the lives of millions of women in India and elsewhere.
Finally I explore the future of blood, which may be synthetic, and why Silicon Valley millionaires think injecting young blood will give them youth (actually a desire as old as humanity.)
Also, there are vampires.