Legends of blood sucking creatures have existed for millennia. Why have people around the world always been so fascinated by vampires? Did vampire tales begin as a way to explain frightening phenomena that people actually witnessed? Although there is no scientific evidence for vampires, there is some scientific basis for vampire folklore.
The vampire has evolved over time in countless directions, moving in popular culture from a pure evil being to a conscience-bound but sexy seducer. The vampires of “Twilight” and “Vampire Diaries” act more human than Bram Stoker’s “Dracula.” However, in general vampires are predatory creatures in human form that survive by drinking the blood of the living through protruding fangs. They are potentially immortal but they can be killed by a stake through the heart, beheading and direct sunlight.
Many vampire behaviors can be explained by medical conditions, such as the rare blood disease porphyria. People with porphyria have an enzyme deficiency that interferes with the production of an important part of red blood cells, called heme. The skin of a porphyria sufferer burns, blisters and scars when exposed to sunlight, so they can only go out at night. This disease can also cause their mouth and urine to turn red, leading to the misbelief that they drink blood. And porphyria is hereditary, so there may have been concentrations of sufferers in certain areas throughout history.
Of course science can’t fully explain vampire myths. Some supernatural magic is required to do that, which is generally more entertaining. So dress up as a vampire on Halloween and just enjoy scaring everyone.
For more information about the science behind vampire folklore, check out my KQED Quest blog.