In 2002 a study was conducted to test the effect of a common bread preservative on children following many anecdotal reports of child hyperactivity after consuming the bread preservative.

The study was published in the Journal of Paediatrics and Child Health.

The behaviour of twenty-seven children on the Royal Prince Alfred Hospital diet, which prohibits food additives, natural salicylates, amines and glutamates, improved significantly.

The children were then given bread containing the preservative calcium propionate (preservative code 282) or bread free of the preservative - placebo. They were allowed to eat four slices per day.
After only 3 days, the behaviour of 52% of children eating the bread with the preservative ‘worsened’ in comparison to the others.

The study authors noted a multitude of symptoms in the children whose behaviour deteriorated including irritability, restlessness, inattention and sleep disturbance. And they concluded, “Minimizing the concentrations [of the preservative] added to processed foods would reduce adverse reactions”.

Calcium propionate (preservative code 282) is very common bread preservative used in many countries worldwide.

Read more about the study here.