Men who watch a lot of porn have less grey matter, study suggests

Researchers found less grey matter in the brains of men who watched large amounts of sexually explicit material, according to a new study.

The research could not determine if porn actually caused the brain to shrink or whether men with such brains were predisposed to watching it, prompting the authors to call for additional study on the topic.

"Future studies should investigate the effects of pornography longitudinally or expose naive participants to pornography and investigate the causal effects over time," said researchers at the Max Planck Institute for Human Development in Berlin. Germany.

The institute recruited 64 male subjects aged between 21 and 45, "with a broad range of pornography consumption" for the study, which appeared in the journal JAMA Psychiatry, the men were not told initially that the research was monitoring their brains on porn, rather that it was "a scientific study including magnetic resonance imaging (MRI) measurements."

They were told during a later phone interview that questions about pornography would be part of the research, and none dropped out.

Participants filled out surveys, describing how much porn they watched. Their responses averaged a little more than four hours per week.