Excuse my retrospect, but I am 100 percent confident that such an issue was paramount some 20+ years ago when I was a school pupil.
Oh whoopee do, new research!! So what? Surely any parent who can read (which excludes a few no doubt) must have realised that evidence has always led the public to accept that E numbers cause hyper-active activity and strange pre-pubetic mis-behaviour.
Remember Kia-ora and Umbonga scares circa 1983 ish?
My son demonstrated an immediate and strong reaction to E110 - sunset yellow in 1987, at the age of about 14 months!
We then shopped and made attempts to avoid it; but you'd be surprised where it turned up, Jellies, KP Skips, Maynards Wine Gums, Tizer, Irn Bru, original Lucozade, corn pads, for God's Sake !
(I think some companies took to using turmeric for the orange/yellow colour eventually).
It was apparent from his behaviour if he had ingested some E110............