If you Google it you will find there is. There are some people who cannot get an erection no matter what, they need to get a "bionic penis" implant.
It has nothing to do with porn consumption and is physiological.
I read somewhere some people have "performance anxiety" after watching a lot of porn and lose their boner before penetration, but that's completely different to "never getting a boner".
What are the physical problems one can get through watching porn? If this study is accurate, it seems batting off more often may be a good thing ?