I thought I'd better read the research before commenting...
"in the sample of 3 year old children Mix A showed a significant adverse effect on the average level of hyperactivity within this group, compared with the placebo, but Mix B did not. For the 8-year old children, Mix B but not Mix A showed a significant adverse effect on the average level of hyperactivity compared with the placebo"
So the effect is age-dependent.
"some specific types of genetic make-up, specifically to do with variations in certain genes involved in the release of histamine from cells, were associated with greater responses to either or both of the test mixtures"
So it's also dependent on your individual genetic make-up.
"had adverse effects on the hyperactive behaviour of some children"
Yes, but how many is some? I suspect it was a minority.
"It is important to note that neither of the challenge drinks equates to any drinks that might be commercially available"
So what they seem to be saying is :
Depending on (a) your age and (b) if you drew the short straw genetically, if we fed you our laboratory-brewed additive potion, you MIGHT become a bit more hyperactive.
Just my opinion, but I think some more work is needed here before we started banning all food additives.