The Truth About Tryptophan
Does tryptophan really make you sleepy -- and is turkey to blame? Experts set the record straight.
Amino Acid Overload
When you eat foods rich in tryptophan, as the food digests, amino acids -
not just tryptophan - make their way into the bloodstream. This causes
competition among the various amino acids to enter the brain.
"Tryptophan, which is a bulky amino acid, would have to stand in line to get
through the blood-brain barrier with a whole bunch of amino acids," Somer says.
"It would be like standing in line when the Harry Potter movie comes out and
you didn't get in line early enough. The chances of getting in [to see the
movie] are pretty slim. That's what happens when you eat a protein-rich food.
Tryptophan has to compete with all these other amino acids. It waits in line to
get through the blood-brain barrier and very little of it makes it across."
The small, all-carbohydrate snack is tryptophan's ticket across the
blood-brain barrier, where it can boost serotonin levels. So have your
turkey, Somer says, because it will increase your store of tryptophan in the
body, but count on the carbohydrates to help give you the mood boost or the
"It's the all-carb snack that ends up being like a sneak preview of the
[Harry Potter] movie, where no one else knows it's showing," she says.
Too Much of a Sleepy Thing
Is it possible to have too much tryptophan in the body? Not really, Somer
says. "Except if you end up eating a lot of tryptophan, it means you're eating
a lot of protein and Americans already eat a lot of protein. It's the only
nutrient we get too much of," she says.
"If you're getting even one serving of 3 ounces of meat, chicken, or fish; a
couple of glasses of milk or yogurt; or if you're eating beans and rice, you
will get all the amino acids you need and in there will be the tryptophan,"
Thanksgiving Grogginess: Look Beyond the Turkey
So if eating turkey isn't exactly the same as popping a sleeping pill, why
the sudden grogginess as soon as our holiday feast is over?
"It boils down to Thanksgiving being a time when people overeat," Jackson
Blatner says. "When people overeat food, the digestion process takes a lot of
energy. Don't incriminate the turkey that you ate," she says of
post-Thanksgiving meal exhaustion, "incriminate the three plates of food that
you piled high."
And let's not forget that the holidays generally mean time off from work and
with family. Many people feel more relaxed to begin with (family wars not
withstanding). Add alcohol to the mix, and voila! Sleep!
Speaking of sleep, Joyce Walsleban, PhD, associate professor at New York
University's Sleep Disorders Center, suggests we all get plenty of it. "Coming
up on the holidays and trying to get all the things done that one would
normally be doing, you short cut your sleep and that's never helpful. By the
time the holiday comes, everyone has gotten sick."
At least then you'll have a good excuse to lay down and take a nap.