By Robert Cohen Executive Director Text Only

WARNING: Don't Trip on the Tryptophan

Each Thanksgiving, tryptophan warnings are issued because
turkey protein contains an excess of this amino acid, and
consumption of tryptophan can make you feel sleepy, affect
your mood, and detract from your memory.

In other words, the average American should not drive,
debate, or take tests of any kind after his or her
Thanksgiving meal.

A Dutch study published in the November, 2002 issue of
Brain, Behavior and Immunity (the official journal of the
PsychoNeuroImmunology Research Society), found that
tryptophan worked directly on the brain to alter cognitive
functioning and produce mood swings and depression in human

The investigators did find some good news. The scientists
noted that the most powerful effects are noted 6-8 hours
after ingestion. By that time, most turkey eaters are

The bad news:

I decided to research and compare trytophan levels in
turkey, cheese, and tofu.

Turkey (the subject of this column) was used as the
standard. According to USDA, a 100 gram portion (about 3.5
ounces) of roasted turkey breast meat and skin contains
0.318 grams of tryptophan.

How much tryptophan is in cheddar cheese? This is not good
news for cheeseheads. An equal portion of Wisconsin's finest
cheddar contains a bit more tryptophan than turkey, 0.320
grams. Go easy on the Parmesian cheese. Parmesian contains
52 percent more tryptophan than cheddar at 0.482 grams.

Good news for tofurkey eaters. Tofu contains just 0.085
grams of tryptophan, almost one-quarter that of cheddar
cheese and turkey.

Just for the record...the mozzarella cheese used on pizza
contains 0.271 grams, nearly the same amount of tryptophan
as turkey.

Most Americans eat turkey on special occasions.
Most Americans eat cheese on every occasion.

Got cheese? Got tryptophan!
Got tryptophan? Got drowsiness, mood swings,
and possible memory loss.

Robert Cohen, author of:   MILK A-Z
Executive Director (
Dairy Education Board

Do you know of a friend or family member with one or more of these milk-related problems? Do them a huge favor and forward the URL or this entire file to them.

Do you know of someone who should read these newsletters? If so, have them send an empty Email to and they will receive it (automatically)!