# Turkey, Tryptophan, and sedation.

**URL:** <https://boards.straightdope.com/t/turkey-tryptophan-and-sedation/46746>\
**Category:** Factual Questions\
**Created:** [December 21, 2000, 7:53pm UTC](https://boards.straightdope.com/t/turkey-tryptophan-and-sedation/46746 "2000-12-21T19:53:16Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Mashie](https://avatars.discourse-cdn.com/v4/letter/m/e79b87/32.png) [@Mashie](https://boards.straightdope.com/u/Mashie)\
**Post date:** [December 21, 2000, 7:53pm UTC](https://boards.straightdope.com/t/turkey-tryptophan-and-sedation/46746/1 "2000-12-21T19:53:16Z")

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I am sure everyone has heard claims that the reason people get sleepy after a thanksgiving meal is that turkey contains a lot of L-tryptophan.

Question one: Is this True? Or is it simply overeating.

I understand the molecular basis for L-tryptophan’s theoretical effect . But is it true that this can result from the levels of typtophan in a turkey dinner?

Question two: If this is true… Why do turkeys have so much damned tryptophan anyway. Do they have tons of a particular tryptophan rich protein in their muscles that other animals (which we also eat) do not?

Most proteins have very similar (if not identical) homologues or orthologues in other species. I would not expect these to have altered trytophan levels to such a significant amount.

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**Author:** ![Ethilrist](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ethilrist/32/4604_2.png) [@Ethilrist](https://boards.straightdope.com/u/Ethilrist)\
**Post date:** [December 21, 2000, 7:57pm UTC](https://boards.straightdope.com/t/turkey-tryptophan-and-sedation/46746/2 "2000-12-21T19:57:31Z")

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Question three: If turkeys have so much tryptophan, how do they stay awake?

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**Author:** ![Mashie](https://avatars.discourse-cdn.com/v4/letter/m/e79b87/32.png) [@Mashie](https://boards.straightdope.com/u/Mashie)\
**Post date:** [December 21, 2000, 9:13pm UTC](https://boards.straightdope.com/t/turkey-tryptophan-and-sedation/46746/3 "2000-12-21T21:13:25Z")

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> [@](#):
>
> \*Originally posted by Ethilrist \*  
> \*\*Question three: If turkeys have so much tryptophan, how do they stay awake? \*\*

AHHH, I assume this is a quip.

However, I will take it seriously just in case.

There is a difference between, containing a lot of tryptophan in the form of long polypeptides (proteins) and “free” tryptophan. Tryptophan containing proteins would not have this affect. Free tryptophan-absorbed by the body from the digestion of high tryptophan containing proteins… in say, turkey… could cause this sedation, theoretically.

However, I was not interested in discussing the molecular basis for the proposed drowsiness. I would like to know:

If the amount of tryptophan in a turkey dinner could cause such effects?..

And what makes the turkey so tryptophan rich?