Search Here

Watching scary movies can literally curdle your blood.

According to a new study headed by researchers from The Netherlands, watching horror movies and feeling fear from them can increase the levels of a clotting protein known as blood coagulant factor VIII.

For the research, the team recruited 24 adults who were aged 30 or younger from Leiden University Medical Center. All of the participants were healthy. 14 of them were randomly assigned to watch a scary movie ("Insidious), which was followed by a non-scary, educational movie ("A Year in Christmas"). The remaining 10 participants watched the same two movies but in the reverse order. Both films lasted about 90 minutes each.

The movies were seen more than one week apart from one another but at the same time of the day. The environment was set up so that the participants would feel comfortable and relaxed.

The researchers had collected blood samples before and after each viewing to test for any increases or decreases in the clotting protein. The participants also had to rate their levels of fear on a scale of 0 to 10, 10 being the worst fear they could ever experience. Unsurprisingly, participants rated the scary movie as scarier on the scale than the documentary.

The team found that after watching the scary movie, 12 participants experienced an increase in the number of clotting proteins while nine had a decrease. For the educational movie, only three had increased levels of clotting proteins while 18 experienced reduced levels.

The researchers noted that although there was an increased in clotting proteins, the participants did not actually develop a clot.

The study was published in The BMJ.