Most people would have read the famous phrase "bloodcurdling scream" in horror stories. But do you think its actually true?
A recent study published in the Journal BMJ
has claimed that fear can actually curdle blood. Researchers from the Leiden University's Department of Clinical Epidemiology, the Netherlands have conducted an experiment to analyze whether blood can curdle while watching horror movies.
‘Horror movies are associated with an increase of blood coagulant factor VIII without actual thrombin formation in young and healthy adults.’
The study was conducted on 24 healthy young participants who were divided into 2 groups, one of 10 participants, the other of 14. The group of 10 was assigned to watch a non-scary educational film followed by a horror film, and the group of 14 was assigned to watch the horror film followed by the educational film, viewed a week apart.
Researchers collected blood samples from the participants before and after watching the movies. They found increased levels of a coagulating factor called VIII in participants who watched the horror movies than who watched the educational movie.
Researchers said that although the coagulation cascade was influenced by acute fear, this did not lead to the formation of thrombin and subsequent fibrin formation. They concluded that in young and healthy adults, watching bloodcurdling movies is associated with an increase in blood coagulant factor VIII without actual thrombin formation.
Reference: Frits R Rosendaal, Banne Nemet, et al. "Bloodcurdling movies and measures of coagulation: Fear Factor crossover trial," BMJ 2015;351:h6367