It’s nice to a see a good study every once in a while and after about 30 years of debating whether preservatives cause hyperactivity/attention deficit. I can’t go into all the studies that have been done because there are too many. Suffice it to say that the methodologies were always lacking, and the results uneven (whether positive or negative).
Now a randomised, double-blind, placebo-controlled trial has been conducted and published in The Lancet (you can get it here for free!). They took 153 3-year olds and 144 8-9 year olds and gave them a sweet drink with either sodium benzoate, a common preservative, and a artificial colors/flavors mix or a placebo. The amount of preservative/color/flavor is less than what many children get in a day. They were tested on a standard hyperactivity index, as well as a attention test. The children were given different drinks on different weeks and since it was double blind, neither the children or the scorers (parents/teachers) knew which drink they got. And since the same children were tested on both, you don’t have to worry about variation between children as much.
Chlidren (both the 3-yr olds and the 8–9 yr olds) given the artificial color/preservative mix had increased hyperactivity. The result was the same no matter how strict you were about inclusion criteria for analysis (e.g. we’ll only look at kids that finished more than 85% of their drink). As expected for any toxicant, some kids were strongly effected and some were not. It’s real, though.
This brings up a problem that public health workers don’t like to think of, much less do something about. The widespread nature of preservatives/artificial colors/flavors, makes this a problem that no one wants to admit to because there are no win-win answers or easy solutions.
The first solution is to make sure your kid doesn’t eat preservatives/artificial colors/flavors. One, that’s expensive for many people. Two, if you’re not cooking/baking a lot, your choices of food are limited because most processed foods have preservatives or artificial colors/flavors. Three, not eating pre-made food can be a difficult switch for many people (what are we going to eat tonight – Gee cooking takes time). So go buy a cookbook (How to Cook Everything by Mark Bittman if you’re only going to have one) and start cooking.
The second solution is for the FDA to get on the stick and re-evaluate these compounds. Why didn’t they fund a study like this decades ago? They should have and (again) really feel down on the job. Seriously, can’t they do anything right on food? Just goes to show why the Safe Food Act needs to be considered and passed. Learn more about it here.