I recently watched the film King Corn. The filmmakers had their hair tested to determine how much of the carbon originated from corn. They estimated that over 50% of the carbon in their hair was directly from corn. Is their a specific isotope that can prove that corn was the source of the carbon?

I found this article that goes into more detail on the science.


I don't know about the study that King Corn used (if any), but the summary of this one indicated that different carbon isotopes can be used to track where the atoms are used in the body of the subject animals. Given that hair is constantly grown, and therefore needing sources of carbon, depending on the volume of corn or corn products consumed, it could be possible, though it would vary greatly by diet.

  • I don't know that the technique in your study can be as specific as corn vs. Other similar plants, but that was an interesting abstract, thanks for posting it. – Dogmafrog Mar 16 '11 at 19:00
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    What this study does (in regards to the question) is provide a method of testing such a claim. You could grow corn in a 13C-rich environment over several generations. You could then feed that corn to your test subjects, and then take hair samples. I'm skeptical that this is the methodology used for King Corn, as the, if I remember right, were talking about all of the carbon from corn that would be coming up the food chain, and that would complicate the experiment tremendously. More likely they just estimated the mass of the corn up the food chain versus other food. – Ustice Mar 16 '11 at 19:12
  • I think you're right – Dogmafrog Mar 16 '11 at 19:14

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