Thursday, April 10, 2008

I am skeptical about food additives - hyperactivity link

I've just read in Yahoo News that EU is urged to ban food additives over child hyperactivity fears. Quoting: "main consumer watchdog called Thursday for an EU-wide ban on six food colourings which a scientific study has linked to hyperactivity in children... A study published in September in the British science review, The Lancet, found that a cocktail of artificial colours and the commonly-used preservative sodium benzoate are linked to hyperactivity in children." The study mentioned is apparently the one by McCann et al., 2007, though the publication date given in PubMed is November, not September.

I am nobody to judge the study, but still I would like to recomment utmost caution about its results and any actions based on them. (And if you are not happy about what I am writing here, please keep in mind that this is my blog and I can write whatever I want.)

It is so tempting to pick an ubiquitous environmental factor that can be avoided only at an incredibly high cost (if at all) and blame on it some public health problem. Or a presumed problem - because I suspect that with today's unnatural child raising methods and paradigms, much of what is inside the normal range of childhood behaviour is stigmatized as hyperactivity.

Children's hyperactivity is sometimes blamed on another ubiquitous environmental factor - television. Not so far ago, a team led by an anti-television crusader published a study showing that television viewing in toddlers was associated with attention deficit at age 7. A skeptic immediately commented that "the message resonates in a society seemingly obsessed with public health villains", critisized the authors' methods and, with a language unusually sharp for a scientific journal, concluded that "the statistics are being used, in the words of Andrew Lang, "... as a drunken man uses lampposts—for support rather than illumination." " Later studies, e.g. this one, did not confirm the TV - attention deficit correlation. However, the jin had been let out of the bottle. The initial message reached the public while its disprovals, as usual, didn't. Just search the Google University and you'll find numerous pages warning you that you'll make your toddler ADHD if you let him in the same room with a TV. (Disclaimer: I am not saying that the best for a toddler is to let the TV babysit him.)

Returning to the main subject of this post, I ask myself - isn't it a bit suspicious that so many unrelated chemical substances in small doses are reported to have the same effect on behaviour?

Why didn't anybody try to conduct a study on animal models? At least, I cannot find such an article in PubMed. Animal studies are generally more standardized and hence more reliable than human ones. I know that in many countries it is easier to obtain a permit to experiment on humans than on animals, but still, why not get to the work seriously and do first the paperwork required and then the animal study itself?

Why was the study done only on children, after hyperactivity problems, when present, are thought to persist for life? Is it because adults are generally happy with their own flawed selves but demand perfection from their children, relentlessly drawing the little ones to some superhuman standards of intelligence and behaviour?

What are we going to do now? Consumers demand the culprit substances to be removed from food. While I don't like the presence in our food of so many chemical substances, often with unknown effects on human health, shall we now have to pay more for food protected from deterioration by methods more expensive than a preservative? Or we'll accept greenish food products and bacteria-caused food poisoning as a part of our lives?

Is it a minor issue to deprive kids of junk food? A person on the receiving end of this treatment testifies that it isn't. In conclusion: The sky won't fall on us if we postpone any action for several more years, so let's wait until independent research teams in other facilities confirm the study's findings, as the scientific method requires.

10 years ago, the same Lancet journal published an article (subsequently retracted by almost all of its authors) claiming that MMR vaccine caused regressive autism in children. Although subsequent studies disproved this work in entirety, the world still cannot recover from the enormous damage done by it. Why not learn from our past mistakes?

Update: At Quackwatch, there is a page titled Twenty-Five Ways to Spot Quacks and Vitamin Pushers, by S. Barrett and V. Herbert. Item No. 6 is: "They Claim That Diet Is a Major Factor in Behavior. Food quacks relate diet not only to disease but to behavior. Some claim that adverse reactions to additives and/or common foods cause hyperactivity in children and even criminal behavior in adolescents and adults. These claims are based on a combination of delusions, anecdotal evidence, and poorly designed research."

Update 2: Interverbal blogged about Feingold diet in 2007.


Highlander said...

everything is unnatural anyway lately :)

Maya M said...

You are right, not speaking about the fact that "natural" substances (i.e. originating from plants and other organisms) have been used as murder weapons for millenia.

daedalus2u said...

There is a possible mechanism involving nitric oxide. Many of these compounds are metabolized by the cytochrome P450 enzymes which are regulated by NO and are highly uncoupled, that is they produce a lot of superoxide as a normal part of their catalytic activity. These enzymes are inhibited by NO, when activated they produce superoxide which destroys NO local to the microsome the P450 enzyme is located in, the lower NO level disinhibits the P450 enzyme which can now metabolize the xenobiotic at a higher rate.

However, this has the effect of lowering the NO level still further. How far that low NO region extends from the microsome depends on what the basal NO level is in the vicinity. If it is low, the low NO region extends farther than if the basal level is high.

Low NO is a stress response. Anything that lowers NO will cause a stress response and will exacerbate any stress response that is ongoing. I think that is what a “melt-down” is, stress induced low NO affecting functional neural connectivity in the brain.

I discuss some of my ideas on mechanisms in my blog on how acute fevers improve autism symptoms acutely.

Maya M said...

I know that NO is your topic of interest, but I am not informed about it and so tip-toe around it carefully :-).
I don't doubt that the link in fact MAY be true and, if so, there must be a mechanism explaining it. However, I wonder why, until recently, nobody had noted hyperactivity-causing effect of ANY substance, while other real psychotropic effects had been well described (e.g. those of alcohol, coffee, marijuana).
Plant-derived psychotropic substances are believed to have the function of protecting the plant by modifying the behaviour of herbivores. A substance inducing hyperactivity and attention deficit would clearly protect the plant; why, then, is this effect allegedly observed for artificial substances only? (In fact, Feingold accused also the natural salicylates.)
Why aren't the alleged culprit substances described as "artificial", as if by "healthy food" tradesmen, and not in terms of their chemical structure?
Does anybody familiar with the ABC of chemistry and biochemistry actually expect a preservative to be "healthy" and coloured substances to be easily metabolized or excreted? Let's remember that a preservative, by definition, must be incompatible with the growth of some life forms, and absorption of visible light requires quite complex chemical structure.
Now, food manufacturers may decide to colour their products by beta-caroten, and I am not sure that it is particularly healthy in large doses.

K said...

Thanks for the information on how food additives might lead to hyperactivity. I wonder if the EU really will ban those additives.

We recently wrote an article on a recent study that showed that certain food additives can could cause hyperactivity at Brain Blogger.The recent study that was conducted by the EFSA that food additives was an interesting one. But will doctors take that into consideration when treating a patient? Will they just prescribe a drug and be done with it?

We would like to read your comments on our article. Thank you.