A preservative found in bread could be to blame for behavioural problems in children, according to a new study published in the Journal of Paediatrics and Child Health.

Co-author Sue Dengate explained that she started studying the mould inhibitor calcium propionate (preservative 282) 12 years ago when she noticed her daughter's behaviour grow worse after she ate preserved bread.

Dengate, a food intolerance counsellor, surveyed the effects of diet 27 children referred because of behavioural problems, and found that calcium propionate was linked to "irritability, restlessness, inattention and sleep disturbances".

When exposed to the preservative, a total of 52% of the children displayed behavioural changes for the worse and only 19% showed a "statistically significant" improvement.

Scott Wiseman, general manager at the Baking Industry Association Queensland, told the Courier-Mail  that only "multinational bakeries and big plant operations" tend to use calcium propionate as a preservative.