By Brian Purtymun
Those of us who sit down to a wild turkey feast this Thanksgiving certainly have a lot to be thankful for. For instance, did you know that at the turn of the 20th century, the wild turkey population in North America stood at less than 30,000 birds? But thanks to the work of federal, state and provincial wildlife agencies and the National Wild Turkey Federation’s many volunteers and partners, there are now more than 7 million wild turkeys and nearly 3 million turkey hunters. The comeback of the wild turkey is one of America’s greatest conservation success stories, and the NWTF is poised to keep the wild turkey’s future bright.
Turkeys are definitely something to be thankful for, but have you ever wondered why you feel sleepy after eating Thanksgiving dinner? Does turkey really deserve the blame, or is it the lop-sided football game on TV or your boring in-laws? Well, the NWTF is here to settle the score about turkey meat, both wild and farm-raised.
Most people have heard of tryptophan, the chemical in turkey meat that leads to drowsiness. But what exactly is tryptophan?
To find out, we spoke with food scientist Dr. James Acton, Ph.D., from the University of Clemson’s food science & human nutrition department. Dr. Acton explained that tryptophan is an essential amino acid that is a basic building block for protein synthesis. In layman’s terms, that means that the more protein-rich a food is, (such as turkey), the more likely it is to include tryptophan. Tryptophan helps your brain produce serotonin, a chemical that makes you feel drowsy.
So, indeed, turkey is partially to blame for making America sleepy on Thanksgiving. But you may have wondered, "Does wild turkey meat contain more tryptophan than farm-raised turkey meat?"
"Wild turkey meat will have about two percent more protein than domestic turkey meat, due to lower fat content," Dr. Acton explained. "So wild turkey meat will have a very slight additional amount of tryptophan content." So it’s true that wild turkey meat is healthier, and it may also make you sleepier than meat from a farm-raised turkey – but just barely.
The NWTF’s Senior Vice President of Conservation Programs, Dr. James Earl Kennamer, explained that wild turkey meat has a lower fat content due to a wild turkey’s diet and living conditions.
"In the wild, turkeys must find their own food, which includes insects, plants, seeds, and berries," Kennamer said. "Due to their lifestyle, they eat natural, wild food devoid of any additives."
Our next question regarded the age-old debate over white meat versus dark meat. Does dark turkey meat make you sleepier than white turkey meat? Dr. Acton told us that, "The dark leg and thigh meat itself, without skin, will average about 27 percent protein, whereas the breast meat averages a little less. Remember, the richer a food is in protein, the more likely it is to contain higher amounts of tryptophan."
So once again the myth proved true, even if dark meat contains just slightly more tryptophan than white meat. But check out the chart at right:
These data reveal that turkey meat is on par with other common meats in our diet, including chicken, beef and fish. But as protein-rich as turkey meat is, it has less than half the tryptophan content of raw soybeans, which contain 0.59g per 100 g of food. Want to fill your stomach, yet stay wide awake? Try a banana; 100 g contains a paltry .009g of tryptophan.
So if turkey meat isn’t exceptionally loaded with tryptophan, where does the drowsiness come from? Why aren’t people falling asleep face-down in their chicken dinners?
The answer lies in the quantity of food that we eat on Thanksgiving.
"When you consider that the typical Thanksgiving meal contains 3,000 calories and 229 grams of fat," said Dr. Acton, "it’s no wonder we feel sleepy after snacking before the meal, eating huge portions of comfort food during the main course, and then loading up on Mom’s home-made pie for dessert."
Eating also triggers your brain to send blood to your stomach muscles to help them churn away and digest the food you just ate, which adds to that light-headed, drowsy feeling.
So this Thanksgiving, after the plates have been cleaned, everyone begins to settle into their chairs and the conversation dies down, you’ll have the answer when that inevitable question pops up: "What’s that stuff in turkey that’s supposed to make you sleepy?"