Please Set Me Straight on Synthetic Yellow Dyes

Dear Ms. Hari and Ms. Leake,

Good evening. Earlier tonight, I read your change.org petition calling for a ban on Yellow #5 (tartrazine) and Yellow #6 (Sunset Yellow) in Kraft Mac & Cheese. I must say that, while not a mac connoisseur myself, I have certainly eaten it once or twice. Furthermore, I agree that all processed food companies should periodically review their popular brands, taking into consideration consumer sentiment, and should make every effort to produce quality goods. 

Since your petition now has well over 230,000 signatories, I assume many in the general public agree with us. But I must know: Where did you source the scientific data for your claims?

Let's start from the top:

"Artificial food dyes...are man-made in a lab with chemicals derived from petroleum (a crude oil product, which also happens to be used in gasoline, diesel fuel, asphalt, and tar)."

Well, I can't disagree with the first part - they're certainly synthetic azo dyes. However, I'd like to discuss your second point, where you equate 'petroleum-derived' to well-known flammable, smelly, or oozy black 'chemicals.' These azo dyes don't really resemble the compounds you've mentioned at all - gasoline and diesel are long saturated chains of carbon atoms, while tar / asphalt are collections of polycyclic aromatic hydrocarbons (PAHs), which might resemble these dyes if you took just the naphthalene portion (right-hand side), deleted the "OH" group, and chained a whole bunch of 'em together.

Yes, azo dyes come from organic chemists (like me!) in a lab somewhere. But, you know what else comes from petroleum? Pharmaceuticals. Plastics. Cosmetics. Synthetic fibers. Coatings. Many of the modern materials you interact with on a daily basis.

"Require a warning label in other countries outside the US."

I believe the US also mandates (Code of Federal Regulations Title 21, section 74.1705) inclusion of tartrazine on labels - I've seen it listed on my mouthwash. (Incidentally, that same CFR page sets exacting limits on impurity content in these dyes)

"Have been banned in countries like Norway and Austria (and are being phased out in the UK)."

Are we just lifting directly from Wikipedia by this point? 

"Yellow 5 and Yellow 6 are contaminated with known carcinogens (a.k.a. an agent directly involved in causing cancer)."

Now here's where things get interesting. Head on over to TOXNET, the National Library of Medicine toxicology database. I've looked up both Yellow 5 (tartrazine) and Yellow 6 (Sunset Yellow), and I can't find any positive studies suggesting carcinogenicity. Ditto both Wikipedia pages, and even my copy of the Merck Index (13th Ed., pp. 9091 and 9157).

What about the potential impurities, you ask? Sunset Yellow can indeed be contaminated with Sudan I (see picture, above), a non-sulfonated version of the compound. Sudan I lists as a Class 3 Carcinogen, which (thanks, ACS!) means "unclassifiable as to carcinogenicity in humans." The European Food Safety Authority (EFSA) actually re-evaluated Yellow 6 in 2009, declaring an acceptable daily intake and noting Sudan I contamination was well below the allowed limit for lead in processed foods.

I won't argue against your claims regarding hyperactivity and allergic reactions; the Hazardous Substances Databank (linked through TOXNET) indicates several studies in which patients do indeed respond poorly to artificial dyes. However, I will note that the responsive patient percentages are often low, and many weren't deemed statistically significant relevant to placebo.

I don't disagree with consumers' rights to petition companies for product changes. But please, check the science, lest you lapse into harmful chemophobia.

Thanks,

See Arr Oh

Update (8:00AM 3/15) - @thefoodbabe contacted me on Twitter with the following: "you are incorrect in your critique of our petition, I've got to go interview live with CNN now - Ciao"

Update 2 (9:00PM 3/15) - CNN posted two responses to the petition.
One leans scientific, the other mostly re-states the bloggers' objectives.

Did Someone Say Pink Slime?

Face it: School lunches have always looked a bit dodgy. Thick, overcooked casseroles. Spongy grey sandwich patties. Slabs of greasy pizza. Thus, when industrial beef producers suggested one more (cheap) processed ingredient, cash-strapped school districts gladly agreed.

Source: theblaze.com

So began the "Pink Slime" fiasco (picked up by the msnbc* Vitals blog, NPR's The Salt, and, of course, our friends at change.org). What is it? If you come from the ranch side of the equation, you refer to pink slime as lean, finely-textured beef (LFTB). Connective tissue and scraps from industrial butcher plants are mixed with ammonia gas or ammonium hydroxide, which degrades the protein matrix of collagen and elastin into component amino acids, and sterilizes the resulting goopy mass against microbes like E. coli. The final product can be blended into hamburger and other "finished" meat products.


So, what are the arguments against this bio-sludge (besides appearance)? First, consider nutrition: there's less in pink slime than in other meat products. There's a higher fraction of insoluble protein, which may be hard to digest, but on the plus side, there's less fat in LFTB than in standard ground chuck. Despite its off-putting look, the final material may actually have a composition closer to soy protein than beef.

pH meter
Source: General Tools

Second, how much ammonia is required? Levels high enough to raise the goop's pH to ~9 seem to kill all pathogens, but batches tested by the NYT back in 2009 showed pH levels as low as 7.75. So what? Well, since pH tracks logarithmically, that corresponds to 18x less total base, which might reduce any ammonia odors but correlates to increased bacterial contamination. 


Finally, it's all about the labeling. A generation of parents accustomed to fighting high-fructose corn syrup (oops, "corn sugar"), artificial dyes, and allergens in processed foods would prefer including ammonia in the final ingredient list. However, manufacturers - and the USDA - consider this a production step, not a discrete additive like ammonium phosphate (leavening agent) or ammonium chloride (licorice, baked goods). 

Mmm...beef.
Source: picturedepot.com

Time will tell if the public uprising surrounding pink slime will lead to cancellation of school lunch contracts. But processed meat products aren't going away anytime soon: consider chicken nuggets, hot dogs, sausages, or scrapple (if you're into that). Or the ubiquitous gelatin, made from bones and cartilage, which gives the gummy to bears and puts the gel in Jell-O. 


*Chemophobia update - Ye Gods, msnbc. Way to scare everyone. How about a scientific fact check? Ammonia is not a "pink chemical" - it's colorless, and you don't use it to leaven cakes (see ammonium phosphate, above). Backtracking to the original report, we see mention of flammability and building bombs . . .really? Ammonia is much more commonly used to clean floors and windows.

Exactly Like Cooking – Corn Meal Mush

Since I started this blog last year, I’ve looked back often at the tongue-in-cheek title. I thought that, like Derek’s delectable experiments, perhaps I should chime in with an offering of my own. However, I thought I’d aim for the opposite end of the culinary spectrum: the starving grad student.

"Piled Higher and Deeper" by Jorge Cham - www.phdcomics.com

Back in school, I not so fondly remember weekends where I had about $5 in my pocket until my next stipend check came in. Sometimes, a trip to McDonald's seemed like a fancy night out. Most of the time, though, I fell back on some tried-and-true favorites: soup, frozen broccoli, ramen noodles, or oatmeal.

But in terms of cost : hunger ratio, I never found a better recipe than this, a See Arr Oh family classic:

Fresh from the pot...so cheap, so good!

Corn Meal Mush (Prep time 10 minutes, serves 4)

3 cups boiling water

1 cup finely-ground yellow corn meal (I prefer Quaker or Goya, but any fine meal will do)

1 tsp salt

1 cup cold water

Procedure – Bring 3 cups of water to a rapid boil. In a separate bowl, pre-mix the cold water, salt, and corn meal together until a loose suspension (no clumps!) forms. Quickly pour the mixture into the boiling water with stirring, and reduce the burner heat to medium-low. Cover pot. Simmer the thickening corn mixture for about 7 minutes, stirring occasionally.

We serve this warm at breakfast, with butter, pepper, and white sugar. I could imagine it seasoned to taste for dinner (cumin, hot sauce, red pepper, soy), or perhaps as a side dish (paprika, parsley, thyme) to a meat or vegetable.

Total Cost: $0.30-0.50 per serving, depending on spices and seasonings