Cats could be making children stupid, according to research that links a parasite they sometimes carry with falling reading and memory aptitude in youngsters. A study suggests that performance at school might be affected by Toxoplasma gondii, a single-celled organism that infects about a third of the world's population and hides in cells in the brain and muscles, often without producing symptoms.Researchers found the parasite, which grows in the guts of cats and can be spread through contact with their faeces, has been linked to reduced memory and reading skills in school-age children.Previous research had linked the parasite to brain tumours in non-human animals. There is also other evidence that the organism has effects on the brain, leading to changes in behaviour.However, the latest study by scientists at the University of Iowa, and at Florida International University, suggests that Toxoplasma gondii might be having a greater impact than previously thought.It suggests that children who tested positive for the parasite had poorer reading and memory scores in cognitive tests, but that doses of vitamin E would reduce the effects.Scientists from the University of Iowa wrote: "The results suggest that Toxoplasma gondii sero-positivity is associated with poor reading performance and impaired verbal memory."Serum vitamin E seems to modify the relationship between the parasite and verbal memory."The scientists cautioned that "future longitudinal studies are needed to confirm these findings and research could include trials of the efficacy of vitamin E in improving cognitive impairment."Toxoplasma gondii can trigger a flu-like illness in those infected, but in many patients it can form cysts in brain cells.Some studies have suggested that the organism can alter the behaviour of humans too, even causing women to cheat on their husbands. Other research has pointed to a link between the parasite and schizophrenia. ..