Jasmine: This is Jasmine.
Chrissy: And I am Chrissy.
Jasmine: We're from NIU STEAM and...
Chrissy: This is The Sound of Science on WNIJ.
Chrissy: Every year, Americans eat over 45 million pounds of poultry during the holidays. Today we're talking turkey about why a good nap completes a holiday meal.
Jasmine: Most people explain the post-meal nap by talking about the tryptophan that turkey contains. Tryptophan is an amino acid that is converted to serotonin in the brain and then converted again to melatonin - a hormone which regulates our sleep/wake cycle. Some people will take melatonin as a supplement before bed to help them fall and stay asleep.
Chrissy: All this is true, but turkey has roughly the same amount of tryptophan as chicken. My chicken fingers don't put me to sleep. And when looking at all the amino acids that are present in poultry meat itself, tryptophan isn't even the most present.
Jasmine: True, but it isn't the quantity of tryptophan, it's how the brain gets it! Carbohydrates like potatoes, bread, and pie contain sugars that are broken down into large amounts of glucose.
Glucose stimulates the production of insulin and that stimulates muscles to take up other amino acids found in the body. Carbohydrates don't contain tryptophan, but they do allow for more
tryptophan to be absorbed by the brain by reducing the amount of other amino acids that are absorbed quicker.
Chrissy: That is a good point, but there still isn't enough tryptophan available to cause the sleepiness alone. Earlier you mentioned serotonin and serotonin works in mysterious ways. lt's converted to melatonin, which makes you sleepy, but a lack of serotonin can also cause lack of energy and fatigue. Not only is your brain taking in tryptophan, but extra amounts of glucose from a carb heavy meal can cause serotonin levels to drop drastically increasing the feeling of a lack of energy.
Jasmine: And you've heard of the flight or fight response...our bodies also experience the rest and digest response. Filling our stomachs with all that goodness signals the brain to secrete hormones to begin the process of digestion, switching off the need to be on high alert, also causing us to relax.
Chrissy: So, the turkey-tryptophan tale isn't completely false, it just needs a little help from its party plate sidekicks and human physiology. This is The Sound of Science on WNIJ, where you learn something new everyday.
