It may not be the Turkey that makes you sleepy.
Carbon monoxide from an electric oven
Cooking the turkey for hours can introduce considerable amounts of carbon monoxide to the home during the cooking process. Turkey has a component that has been attributed to that nap after dinner. Others hypothesize it is just eating too much that leads to sleepiness. It is also possible that exposure to Carbon Monoxide is a contributor.
If carbon monoxide is a culprit, it is not only related to gas ovens.
I am not sure how much CO is given off in an electric oven during the cooking of a turkey, but certainly some amount is likely. I will have to wait until Thanksgiving to get more information on that.
Considerable is created when using the self-clean function of the oven.
My own oven gives off between 28 and 3 PPM for the first 1-1/2 hours of the 3 hour cycle. After that time, whatever was creating the CO was successfully incinerated and CO levels dropped to normal.
These amounts are perhaps not enough to kill you, but certainly enough to affect a person–especially infants that might be around.
In the first 15 minutes of operation, my own oven gave off about 28 PPM, after about half an hour it settled down to 12 PPM and after about an hour it was down to 5 PPM. At the one-hour mark, ambient CO levels in the kitchen 10 feet away from the oven hovered around 3 PPM—with the exhaust fan on and a window open.
I suspect the amount of CO will depend on what the oven is burning off in the cleaning mode, and levels likely could be considerably higher, and for longer periods of time, if the oven is not cleaned very often. I clean min probably twice a year. I may start doing it more often now.
Of course your ordinary CO alarm is “not allowed” to alarm, per its listing, at these low levels, so most of the time you will have no idea why you need a nap.
I think the lesson here is to clean your ovens regularly–don’t wait until you can see the bottom of the oven. You should also run the kitchen exhaust hood the whole cleaning cycle and keep a window open.
Perhaps I will go take a nap, while I wait for the oven to finish.
Charles Buell, real estate inspections in Seattle