Impress your friends and family this Thanksgiving with some tidbits about the chemistry behind the big meal.
Read this and you can put a stop to that tryptophan myth: that one you’re always hearing about how all the tryptophan in turkey sends you into a stupor. Tryptophan — an amino acid — is not to blame.
That’s just one lesson some College of Wooster professors teach in their annual class focusing on chemistry and Thanksgiving.
Here’s more on the tryptophan tall tale and some other morsels that chemistry professors Paul Bonvallet and Judy Amburgey-Peters share with students, and now you:
• Tryptophan’s bad rap: Bonvallet suspects it stems from the fact that it can be converted into serotonin (that’s the neurotransmitter responsible for feelings of calm and well-being) and then the hormone melatonin. Both can cause drowsiness.
“There is a grain of truth to it,” Bonvallet said. “If you take tryptophan on an empty stomach, it will make you feel sleepy … it’s prescribed to treat sleeplessness or depression,” he said.
But, he said, “I did a calculation and you’d have to eat a pound and a half of turkey to get the same dose that you would get in the form of a tryptophan supplement, and you’d have to eat that on an empty stomach.”
“Blame biology,” Bonvallet said, “rather than chemistry for that feeling of sleepiness after the big meal.”
Blood gets diverted from your brain to help with digestion, slowing down bodily processes. “It’s a very mild form of oxygen deprivation,” he said. “There’s only so much blood and if your stomach has a huge demand, it has to be taken away from somewhere else.”
• Pumpkin pie is good for you: Well, the orange pumpkin part is anyway.
Pumpkins are high in beta-carotene. That’s the same molecule that gives carrots, sweet potatoes and other orange vegetables their color. Beta-carotene is an antioxidant, helping to minimize the formation of free radicals — reactive molecules that are naturally produced in the body, but can cause harm.
Pumpkin also is a good source of Vitamin A.
“Of course, the counterbalance is that you’re eating whipped cream on top and there’s sugar in the pie,” Bonvallet noted. “With everything, it’s a matter of moderation.”
Speaking of fat, there’s what we call the bad fat (saturated), and the good fat (unsaturated). Bonvallet tells his students, “there’s just a very subtle chemical difference between the two.” And for unsaturated fat, the difference means a much shorter shelf life at the grocery store.
That’s why the word “hydrogenated” shows up on food labels, he said. Hydrogenated fat, created by introducing more hydrogen atoms into an unsaturated fat, is more shelf-stable but less healthful, he said.
• Cranberries are on the same team as pumpkin pie: Amburgey-Peters notes that cranberries also are high in antioxidants. “Any time you have a food product that has got color to it, it is useful to trapping those free radicals … so they don’t do damage to your body,” she said.
That’s why, she said, “it’s important to eat the rainbow … the more color in it, the more antioxidants it’s going to have.”
Cranberries get kudos from Amburgey-Peters for another reason. Cranberry seeds are rich in omega-3 and omega-6, what is called “essential fatty acids,” which are not produced by the body and must be obtained through food. Cranberry oil, anyone? Yep, it’s available.
• Bread basket: The bread and its basket are chemically similar. So why can’t you eat wood? They have the same molecular formula (same number of carbon, hydrogen and oxygen atoms), Amburgey-Peters explained, “but you can zoom in one type of bond that is different.”
That difference “is the major reason why our bodies can break down the carbohydrates of bread, but we can’t break down the carbohydrates of wood,” she said. “We just don’t have the enzymes in our body that will break [the bond] in wood.”
On that note, have a happy Thanksgiving, and here’s hoping you create some warm bonds with those at your table.
Katie Byard can be reached at 330-996-3781 or firstname.lastname@example.org. You can follow her @KatieByardABJ on Twitter.