There are some important things to keep in mind here, like the fact that 15 of the 17 studies were case-control studies.

This kind of research can’t show cause and effect, and it often doesn’t account for factors that may have affected both the exposure and the outcome.

The researchers also highlight the low quality of a number of the examined studies.

Results were inconsistent across studies, but those of higher quality suggested that associations in unadjusted models might have been due to factors that could have influenced the results.

I appreciate having an article on this topic, but the headline is a little strong.

A full half of the global human population is infected with toxoplasma gondii, and human infection isn’t associated with cat-ownership, so that explanation seems unlikely.