Food dye—a new bugaboo

If you’re around my age, you remember the disappearance of the red M&M. One day, they were just…gone. Apparently, folks worried that a red food dye not even used in M&M’s caused cancer.

Well, the red ones came back, but food dyes are back in the news. The Center for Science in the Public Interest is concerned about a possible link between certain food dyes and (presumably bad) child behavior.

Now I don’t really care what color my food is (unless my lettuce is brown and my meat is green), but these dyes are used ubiquitously to make food appear appealing, appetizing, and profitable. Given that these dyes don’t contribute nutritionally, there really is no health reason to use them, but food producers like them because they work; they help sell food.

What’s the claim, and what’s the science?

The CSPI claims that there is an association between certain food dyes and childhood hyperactivity. Part of this is based on the “Feingold Diet” of the 1970’s, which they claim improved hyperactive behavior by eliminating food dyes, and some is based on a limited number of published scientific studies.

The studies of the Feingold diet are not particularly strong. There have been more recent studies of food dyes and behavior. One large, double-blinded, placebo-controlled study published in The Lancet last year found an association in certain limited age groups (3, 8, and 9 year olds), but not others (The Lancet, 370(9598), 3 November 2007-9 November 2007, Pages 1560-1567).

The data are not convincing. The measured behavioral changes were not great. There is a great deal of variability in any single child’s behavior, and there are a myriad of non-controlled effectors of child behavior. When a study finds a statistically significant finding such as this, we must also ask, “is it plausible?”

At this point, there doesn’t appear to be a plausible mechanism for this purported effect. Also, why would these age groups be so much more susceptible than others? There was also a great deal of variability among children, not just among groups, which makes explaining correlations difficult (but not impossible).

The European Food Safety Authority has rejected these findings. Should we?

Of all the factors that can affect children’s health, positively and negatively (infectious agents, seat belts, vaccines, bike helmets), any food dye effect would appear to be quite minimal.

That being said, what use are food dyes?

To the consumer, food dyes are not much use at all. To the manufacturers, well, that’s another story. Of course, many of the anti-food dye folks also go after common preservatives, without which our foods would be more dangerous and less palatable.

I wouldn’t rush to empty my cupboard of dyed products, but like any other industrially produced and consumed product, it’s good to ask questions, questions like “what is the risk” and “what is the benefit”. It would appear that the risk is small. It would appear that the benefit to consuming them is non-existent. The next question is, is there any point in banning a probably harmless but (to the consumer) useless substance?


19 responses to “Food dye—a new bugaboo”

  1. Oscar “I have sandwiches, they are green or brown.”

    Felix “What are the ‘green’ ones”?

    Oscar “Either new cheese or old meat.”

  2. I was talking with the VP of sales for my company at a lunch meeting, and he used to work for a “natural” breakfast food company (owned by a large well-known company, but we’ll leave it at that). He was doing some QC inspections (for lack of a better term)and saw a vat of red food dye with a Poison warning stamped on it. Kind of odd that a “natural” food company was using a poison to color their food, eh? BUT in reality, the dye is poisonous only in large doses (kind of like citric acid, or anything else for that matter). The VP was talking about how this was a major part of his visit to the production plant, and discovered you’d have to consume some 700,000 servings in as little as 2 hours to have any POSSIBLE effects (it’d take much more than that to cause any true health concerns). Thought that was an interesting one…

  3. In the bird feeding world, it is recommended that you not use red-dyed hummingbird feeder juice because, apparently, it makes them buzz around like bees.

    So you get this clear hummingbird liquid feed.

    Then when no hummingbirds come for a while you put red dye in it.

    (I should say: I am joking. When your hummingbirds start looking relaxed and laid back, call the bird doctor!)

  4. Denice Walter

    OK, let me get this straight:food dyes (and sugar)cause hyperactivity.Vaccines cause autism.SSRI’s cause classroom shootings.Psychiatric drugs cause psychiatric symptoms(in a rather specialized fashion, e.g.drugs for schizophrenia cause symptoms of that illness, etc.), So, if we eliminated these substances, all of these behaviors/ conditions/illnesses would disappear.Wow! Why didn’t they teach us that in grad school?

  5. Elf Eye

    First, this is anecdotal, so take it for what it’s worth. It has nothing to do with dyes as contributing to hyperactivity but rather with the possibility that some people may be allergic to certain dyes. My daughter was experiencing outbreaks of hives so severe that one day I took her to the emergency room. The ER doctor guided us through a reconstruction of everything she had recently eaten or daubed on her skin. Anything new? Anything different? One thing and one thing only: My daughter had downed a nice, tall cool glass of red Koolaid at a barbecue at a friend’s house. The ER doctor advised us to avoid red dyes, and in a follow-up visit with an allergy specialist, we received the same advice. (Alas! Turns out that red dye is everywhere. Yesterday I was about to purchase a can of vanilla icing, for FSM’s sake, and discovered it contained red dye!) We have scrupulously avoided red dye, and my daughter hasn’t had another episode of hives. Again, I know this is anecdotal, but given that dyes add no nutritional value to foods, I wish food manufacturers would err on the side of caution.

  6. The BMJ link is paywalled – I assume the ‘findings’ the ESA have rejected are the weak link, not the absence of a link?

    In Europe, of course, all food additives have to be listed so the consumer is able to reject food with some added colourings, which we did for our sons, who appeared to show some effect, but not our daughter, who didn’t.

  7. Another Anonymous Poster

    Question: Is it actually the dyes that might cause a problem, or might it be that feeding your kids enough of the kinds of foods that contain such dyes is more of an issue? It seems to me that if you stuff a kid full of cheetos, M&Ms, and other super-processed crap, that even baby Albert Schweitzer might develop behavioral problems.

  8. Perhaps this is a generational thing, and it also might be redundant with AAP above me’s comment, but growing up my siblings and I just weren’t allowed to have foods that had dyes, except once or twice a year on special occasions (Halloween, birthday parties).

    Is it because foods commonly given to children now, all contain dyes where they didn’t used to? Or because the diet of the average child has changed and now routinely includes foods that were considered unhealthy 25-30 years ago?

  9. Ktesibios

    The red dye that caused trouble for Elf eye’s daughter was very likely carminic acid, or carmine, which is made from the cochineal insect. After being hammered into near-unmarketability by synthetic dyestuffs, cochineal made a comeback as a food coloring due to fears about synthetic food colors. While it had been used in foods and even as a medicine for hundreds of years, there are known cases of allergic reactions to carminic acid.

    In the USA, this dye might be listed in the ingredients as “carmine”, “carmine lake”, “carminic acid” , “natural red 40″or even just “color added”. In Europe, it might be labeled as “E120”. It’s a very widely used food coloring.

    Sometimes I have a bit of fun telling people that the pretty red stripes on a candy cane might be made out of dead bugs.

  10. This is yet another reason for ensuring that everyone gets a good education in science and reason.

    Maybe if enough people grow up learning or rationalizing that we can get (say) strawberry soda which is clear (and actually contains no strawberries!), and it tastes exactly like the “traditional” soda, we can dispense with the food dyes because they really don’t matter.

    But as long as everyone thinks strawberry or raspberry drinks just have to be red, blueberry yogurt has to be blue, banana milk shake has to be yellow, etc. (but curiously, such products with “blackberry” are never black!), we’re never going to get rid of unnecessary additives regardless of whether they actually do cause problems.

  11. “Or because the diet of the average child has changed and now routinely includes foods that were considered unhealthy 25-30 years ago?”

    I don’t buy that at all. My diet and the diet of most kids my age consisted of a ton of junk food 30 years ago. I would like to hear some of these foods that were considered unhealthy 25-30 years ago. It’s just now there are more brands of unhealthy products and consuming larger quantities of these unhealthy items.

  12. minimalist

    Fine fine great fine, so what are they going to do about those cockroach shells in the green M&Ms?!?!

  13. I’ve been trying to explain this to my sister for some time. Her two kids have both been diagnoses with ADD and she blames the chemicals in food and limits their food to all natural. She claims it helps, but personally I do not she it.

  14. synapse

    My brother is also severely allergic to red dye; he gets very severe hives. We avoided giving him any artificially colored foods while he was growing up. It definitely didn’t fix his other problems (delays in verbal development, problems with abstract thought, obesity).

  15. Egaeus

    Another example of fine scientific analysis by the Center for Scaremongering in the “Public Interest.” I’m expecting them to start warning against toxins in vaccines any day now.

  16. I have a possible mechanism which (of course) relates to nitric oxide. Dyes are xenobiotic chemicals and many of the effective ones contain aromatic groups (a chemical ring where the bonding is enhanced by “resonance”) because many aromatic groups absorb light well so they make good dyes.

    Virtually all aromatic compounds are metabolized by the cytochrome P450 enzymes. The P450 enzymes are quite “uncoupled”, that is while consuming O2 they produce superoxide. Mitochondria do this too, but mitochondria are highly coupled, that is the electron flow is coupled to the membrane and doesn’t leak off. Usually at most a few % of O2 gets converted to superoxide by mitochondria. The P450 enzymes can convert as much as 50%. This actually is a “feature”, where normally the P450 enzymes are inhibited by NO binding to it. When the P450 starts to oxidize substrate, it generates superoxide, the superoxide pulls down the NO level, the P450 enzyme becomes uninhibited and the metabolism of the xenobiotic is accelerated. A good control scheme to deal with xenobiotic chemicals that might be toxic, such as bacterial toxins.

    The liver has a lot of P450 enzymes, but so do many other tissue compartments including the skin, and the brain. The brain makes and metabolizes steroids and so it requires P450 enzymes. Similarly the skin does too. The skin also contains xanthine oxidoreductase. The skin is the place where many xenobiotics first make contact with the body.

    The decrease in NO caused by activation of P450 enzymes activates other things too. The master switch of inflammation, Nuclear Factor kappa Beta (NFkB) is inhibited by NO, and becomes more active when NO is lowered. Inflammation lowers NO still more, the positive feedback robustly turns on inflammation. That inflammation exhibits hysteresis, it can’t be “turned off” without an external source of NO. That is where my bacteria come it. More NO turns down the “gain” of the P450 activation, and also the “gain” of NFkB inflammation. In the skin, mast cells are sensitized by low NO, so they become more sensitive by anything that lowers NO levels. Turn the gain up high enough (i.e. to 11), then there can be activation even without a signal.

    I think that this metabolism of xenobiotics in the skin can also contribute to Stevens Johnson Syndrome. I suspect that SJS might be a “feature”, that if you get such a severe dose of cooties on your skin, infection, or glob of poison, or some blood from the creature in Alien, the “best” solution might be to kill off the affected skin and have it slough off. One of the most common drugs that causes SJS is allopurinol which inhibits xanthine oxidoreductase (XOR). A major role of XOR is to make nitrite from nitrate and NO from nitrite and a major site for it is in the skin. When XOR is acted upon by proteases (such as are released from mast cells), it turns (irreversibly) into xanthine oxidase (XO) which doesn’t make NO, only superoxide.

    This could explain both the behavioral and skin rash/hives symptoms. Low NO in the brain will mimic the same symptoms as stress, such as invoking a melt-down.

    Hyperglycemia can do the same thing. Hyperglycemia does cause the production of superoxide, which also lowers NO levels. That effect is more limited to the vasculature but that vasculature includes the brain. A superoxide mediated decline in brain NO would act right through the brain blood barrier. I suspect that low NO in the brain is the final common pathway by which some food dyes and excess consumption of sugar sometimes cause behavioral problems. The solution is to raise NO levels. I discuss this in my blog on the physiology behind how acute fevers cause the resolution of some symptoms of autism.

  17. Ubi Dubium

    Wow, thanks, daedalus2u!

    I also have a child who gets hives from Red #40. We have never had a problem with other food dyes, but unfortunately Red #40 is nearly ubiquitous. It took us some time, and some trial and error, to figure out what was causing the hives, but once we specifically eliminated Red #40 from her diet the problem was solved. (She also has ADD problems, but we have never been able to directly link her inability to concentrate to consumption of specific foods, so I have no evidence that would lead me to suspect that it is food-related.)

  18. doug l

    The persistence of bad information is everybit as hard to overcome as the most preposterous of groundless superstition it seems, even among those who should know better.
    I remember how it used to be a defining fact that stomach ulcers were caused by stress and it took over 20 years to overcome that concept. If something which had been studied for so long and so much and as straight line as that can take that long to get the medical/scientific community to accept that it’s been wrong, it speaks volumes as to how much regard one should place in the consensus regarding anything (I’d include the CO2 connection myself). I’m sure that 99 percent of people (smart people with modern educations) are still convinced that after exercise sore muscles are caused by lactic acid buildup in their muscles. Our superstions these days are based on erroneous or oversimplified analogies from our early education, such as the “greenhouse” effect…useful to illustrate a principle for an unsophisticated student but not exactly the way it works.

  19. The thing about this that bothers me is that I had always figured that under their ridiculous attention-whoring publicity methods, the CSPI had a solid core of science backing up their dramatics. Evidently I was wrong.

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