Biliruben Is the Secret

Well, someone at the Penn State Food Science department has a sense of humor.  Ha ha ha.  Have you followed my attempt to contact Galliker’s, the Yahoo! Answers question, posing the question to Turner’s, and Turner’s final suggestion?  OK, then you’re caught up… and you can read this.  I emailed the following to a bunch of people there, and as of yet have only received one reply.  Here’s the email:

from: ERiC AiXeLsyD  <world.and.lunar.domination@gmail.com>
to: foodsci@psu.edu
cc: ca3@psu.edu, xd11@psu.edu, jdf10@psu.edu, tsd3@psu.edu, sep14@psu.edu, jmw5@psu.edu, jxc16@psu.edu, moconnor@psu.edu, emills@psu.edu
date: Fri, Aug 13, 2010 at 11:03 PM
subject: Blue + Brown = …Green?
mailed-by: gmail.com

Salutations Savvy Sustenance Science Scholar Staff!

I write to you today with something that has had me perplexed for quite a while.  It was recently suggested to me that you would be the the ones with the most knowledge and best skill set to deal with my query.  I of course, thought that this was a splendid idea… which is why I’m (obviously I guess) writing to you now.

Do you like “blue flavored” drinks and Popsicles?  I do.  I enjoy them quite a lot, actually.  Whether it’s the seemingly fictional blue raspberry, some sort of punch, Faygo’s Jazzin’ Blues Berry, or “Bug Juice”… I just seem to gravitate to blue colored drinks.  As of late, I’ve noticed an interesting side-effect of said blue flavored drink consumption:  For some reason, it tends to turn my feces a quite disturbing shade of green.

First, I wrote to Gallagher’s and my missive went unanswered.  Perhaps they did not find the humor in my inquiry.  Perhaps they were upset that I mentioned rival dairy, Turner’s, as having a better Iced Tea.  Perhaps they were offended that I offered to provide photos as evidence of my brightly-hued chartreuse bowel movement upon request.

Second, I posted a question to the Yahoo! Answers community, and wasn’t exactly satisfied with the answer.  I understand the general concept that what you eat determines the contents of your waste, but want a deeper explanation.  Why does the blue dye turn out so green?  Why doesn’t it come out blue?  What is going on in there?  What exactly isn’t digesting?  Does that much blue dye really need to be there?  Are my insides dyed blue or green after it comes out?  Is it harmful?  Are my intestines playing some sort of practical joke on my eyes?

In a tertiary attempt to unravel the mystery at hand, I contacted the good people at Turner Dairy Farms, and was met with a couple of responses, each unfortunately unable to answer my original question… but courteous and accommodating nonetheless.  It was a Mr. Yon & his Quality Control Manager at Turner’s who directed my attention to your esteemed department as the group that would successfully be able to provide a satisfactory explanation of the process behind the green from my behind.

I would really appreciate any insight that you may have on the situation.  Have studies been done about this phenomenon?  Has anyone ever asked you about such things before?  I have so many questions, and you’re the  education experts!  I really appreciate your taking the time to read my email, and thank you in advance for your assistance!

The Emerald Excreter,
-ERiC AiXeLsyD

Perhaps it was too goofy for all the other stuffy scientists?  Maybe they’re scared of the Emerald Excreter!

At any rate, I got an amusing an informative answer (finally):

from: EDWARD MILLS <ewm3@psu.edu>
to: ERiC AiXeLsyD <world.and.lunar.domination@gmail.com>
date: Wed, Aug 18, 2010 at 2:07 PM
subject: Re: Blue + Brown = …Green?
mailed-by: psu.edu

Eric,
Interesting question with possibly a very simple explanation.  The human eye sees green when blue and yellow light are reflected simultaneously from a surface.  Blue food dye reflects blue light.  Find a yellow dye to go with it and you could account for the observed green.

I would speculate that the blue food dye is passing through your GIT largely unchanged and is not absorbed across the gut wall. One of the more common pigments of normal stool in biliruben a yellow pigment (derived from hemoglobin or myoglobin breakdown).  Put the two together and the resulting stool might appear green.

Have a great day!
Ed Mills
814-865-2394

Win!  I did have a great day Mr. Mills, thanks to your easy to understand explanation.  Finally, the great mystery is solved!