Every year we hear the same thing regarding turkey at Thanksgiving – it makes everybody sleepy because of the high tryptophan levels. Turkey, tryptophan (an amino acid), and sleepiness are so closely linked you’d think the birds would come with one of those, “Don’t operate heavy machinery” warnings you see on certain medications. Interestingly though is that the feeling of physical and mental fatigue so many get from Thanksgiving dinner has nothing to do with the turkey. Actually, tryptophan levels in turkeys are pretty much the same as in other meats, such as beef and chicken. Eggs have close to four times the amount of tryptophan but you don’t hear anyone talking about an “omelet coma.” (For the record I’m taking credit for coining that false term.)
So what’s the deal against turkeys and is this a plot set forth by Vegans? I’m not sure if we can point the finger at Vegans, but I can tell you with certainty that the reason is not because of the turkeys, but because of the high amount of carbohydrate-rich foods consumed during Thanksgiving. Hmmm…Vegans like carbs – interesting. Okay, enough giving those Vegans a hard time, for now.
All the high carbohydrate foods, especially the sugar (and alcohol) consumed during Thanksgiving stimulates the release of insulin which then carries most of the other amino acids from the blood into the muscles, except for tryptophan. Left hanging out in the blood, and now unopposed by other amino acids, tryptophan is allowed to cross the blood brain barrier. When it does get to the brain it triggers an increase of the neurotransmitter serotonin, which has a sedating effect on your body. (Think Lexapro & Prozac if you’re into medications.) Furthermore, this increase in serotonin can continue on and increase melatonin levels, which is the hormone naturally made by your pineal gland when it is time to sleep.
Additionally, the more stuffing, potatoes, gravy, sugary cranberry sauce, pie, and other carbohydrates consumed subsequently produce more insulin. This will eventually result in your blood sugar crashing down, so you’ll become even more tired. Actually, too many carbs, especially those refined carbs, over time can lead to depression; almost like Thanksgiving every day in your head, and that’s not a good thing. For more on carbs and insulin, click here.
The sugar-tryptophan connection is also the reason why a warm glass of milk before bed helps some people sleep. It’s the milk sugar (lactose), not the calcium or any other nutrient in the milk. And this is the same reason why some nice hotels offer a candy on the pillow or a cookie before bed to their guests, (yeah, it’s a nice gesture too).
How about the opposite effect of carbohydrates and tryptophan? That would be another amino acid called tyrosine and not more carbs but actually protein (or the absence of excess carbs). The increase of tyrosine in the brain allows for more norepinephrine to be produced and that is actually a stimulant to the nervous system. So, if you ate mostly turkey with a bunch of green vegetables for Thanksgiving (kinda like a Paleo-Type meal) then you would actually have the opposite effect – that of an upper rather than a downer. Tyrosine is also a precursor to thyroid hormone, and that’s very important as without it, hypothyroid symptoms might occur such as weight gain, fatigue, and poor mental clarity. Hey, sounds like Thanksgiving meal all over again.