I thought this was a site where science was discussed, but I have been disappointed by the lack of engagement with the facts, and the rather abusive nature of some of the comments.

EFSA had a legitimate concern, which they state, that the manipulation of the data could affect the outcome of the statistical analysis. When they did the re-analysis, several of the statistical findings evaporated (page 3). It is really difficult to pick up this bit of science from the summary above.

The only significant thing in the GHA is the parental response, as agreed by EFSA, the Stephenson paper, etc. Why does anyone take exception to the finding that parental findings that cannot be replicated by independent observers are of “unknown clinical relevance” ?

Nonetheless, the blinding test is described in the Lancet paper, in the last paragraph of “Study design and challenge protocols”. Their X2 value for the blinding test is 4.4, and the 1 in 20 cut-off is 6. It is also a bit interesting to have done the blinding test in two tranches. If there is any batch-to-batch variation in the colour of the juices, this could change the outcome of the blinding trial.

Just directly answering your point, this is a test of blinding. Statistical significance in the outcome would show that the participants were not blind. They didn’t test as big a group as they did in their study, and they didn’t test in children; children are sometimes able to discern tastes that adults cannot. You could certainly argue that they have not tested the blindness of the study as rigourously as they could (and should) have done.

it is worth parsing that carefully. That is both scientific expert groups declined to accept from this study that the chemicals caused hyperactivity.

by contrast, para 22 sets out the FSA reasoning:
“The available
evidence now leaves uncertainty as to whether that safety can be confidently asserted”

so FSA is acting because it is uncertain as to whether the chemicals are safe. Now it strikes me you could have a good debate as to whether this, err, principle, is good or bad science.

other interesting reading is the publically available report on this research (www.food.gov.uk/multimedia/pdfs/additivesbehaviourfinrep.pdf). Figure 5 shows that objective observers couldn’t detect any effect of gving additives. Disaggregated analysis of the GHA (annexes) shows that, oh, surprise ! it is only the parents that picked up any results.
(and did you know that parents had to volunteer to take part in the study ?)

There is also the issue that this is a double-blind study. It might have escaped some people’s notice that this is a test of four food colourings in a drink. So how do you fill a drink with food colouring, and still have a blind trial ? Enquiring minds might think that this is an important question…

Para 10 of the COT opinion makes clear that two panels of 20 adults were tested, so 40 in total. Now as it happens, in the main study, you have a sample size of ~120, and the results are only borderline significant with this sample size (oh, and contradictory between different age groups). Do you really think you can safely conclude that the sample was blinded, when you only tested 40 adults, and the results were skewed ?

> With regard to food colourings, there are no known benefits (except for marketing purposes)

I think that’s a little glib. Fact is, the reason that certain colours of certain foods work well for marketing purposes is that lots of people like them. Now, I’m not one of them: I prefer my raspberry yoghurt not to be bright purple and am quite fond of food that looks sort of greyish as long as it tastes good — Patum Peparium, for instance. But that’s just me. I’ve met plenty of people — I’m sure we all have — for whom the colour of food is so important that they will actually refuse to eat stuff that looks wrong to them. I may think they’re all a bit barmy, but I’m not sure that’s a reason to ban stuff they like. And I’d hesitate to claim with such confidence that the only benefit of allowing fussy eaters access to food they’ll eat instead of food they won’t eat is “marketing”.

I am quite prepared to accept that what i said was approximate rather than precise. However, please feel free to share any facts that contradict what I said. If you can, I will apologise.

if you cannot, perhaps you can explain why you labelled my comment as gibberish ?

They tested two groups of twenty people to see if they could discriminate between the drinks, and pooled those data; the data don’t quite cut statistical significance. So it is only just double blind. But hey; why test more people when you could ruin the blindness ?

reader beware, as far as i can tell this is just gibberish.

The GHA is great.

well, what the gha covers up is that the only thing that comes out significant is the parent’s viewpoint. When the kids were put in front of a medic, or impartial observer, there was no significant effect.

And it is actually one of the key issues as to whether the GHA has any clinical relevance.

Given this, it should be noted that limits tend to be rather random. Working out what levels constute a risk is hard for substances that are not obviously toxic (perhaps having an LD50). Thus a ban on the basis on potential, but difficult to quantify risk is more honest than a limit based on levels.

If a manufacturer wishes to continue to sell or use additives with little obvious benefit to the consumer, the onus should be on them to carry out safety studies with the power (read many thousands of subjects) to detect side effects.

Clearly if there are obvious public health / food avaliability benefits to an additive, then this complicates matters.

So breakfast cereals and those radioactively colored boxes of sugar water lose all or nearly all of their fake coloring (and mums of the world rejoice, as the amount of stained clothes and furniture and floors is reduced), but we’re not looking at an outright ban.

That gives us a reasonable step in the right direction and a reasonable start in improvements while we continue the research. It also gives us some flexibility, since a phased approach gives us time to adapt and identify any potential problems.

As we all know statisticas never ever tell you *whether* something is caused by chance, only how often it would occur *if it was* caused by chance.

Any conclusiosn beyond that fact (what was it in this case, 1 in 20… 1 in 100?) is the job of our brains not our statistics and depends on klnowing far more than the a-obtained.

That said, it was Gillotin who had initially raised the concern that the then-current execution methods left something to be desired – and who proposed that the matter should be resolved by men of science acting rationally to find an effective solution.

I believe a guillotine is traditional.