Could eating rare-cooked meat give you road rage? That is the intriguing question posed by new research into the parasitic bug toxoplasma gondii which will, at some point, infect half of adults.
The bug causes toxoplasmosis in the brain and we contract it primarily from handling or eating raw and undercooked red meat, such as lamb, or through contact with cats.
In most cases, the parasite is infective for only a few weeks after you have contracted it, though the very mild flu-like symptoms of initial infection are usually so subtle that most people never notice they have had it; then the bug goes into a long-term dormant or 'latent' stage.
This dormant stage was considered generally harmless, but that view is now changing, thanks to mounting evidence that it can influence people's behaviour by altering the chemistry of their brains, making some people more aggressive, reckless, impulsive and more likely to put themselves in danger.
Last month, scientists at the University of Chicago reported that people who explode into bouts of extreme anger such as road rage are twice as likely to have dormant toxoplasmosis.
'Our work suggests latent infection with the toxoplasma gondii parasite may change brain chemistry in a fashion that increases the risk of aggressive behaviour,' says Emil Coccaro, a professor of psychiatry and behavioural neuroscience, who led the study of 358 adults. He stresses that he has not established cause and effect, which is difficult to do when linking highly complex brain chemistry with behaviour.